Term
| What is the function and chemical composition of peptidoglycan in bacteria? |
|
Definition
- Sugar backbone with cross-linked peptide side chains
- Gives rigid support and protects against osmotic pressure (present in gram + and -, but thicker in +) |
|
|
Term
| Describe the major structural differences between gram positive and gram negative bacteria. |
|
Definition
BOTH can have: Capsule (anti-phagocytic), Pili/Flagella (Adherence and sex/ Motility), Peptidoglycan (resist osmotic pressure), Cytoplasmic membrane (oxidative and transport enzymes)
1) Gram positive Positive
- Thick peptidoglycan
- Lipoteichoic acid as a major surface antigen, which induces TNF and IL-1
2) Gram negative
- Outer membrane with LPS (Lipid A endotoxin, which induces TNF and IL-1 and O antigen Polysacharide at surface)
- Periplasm between outer membrane and plasma membrane: Hydrolytic enzymes like beta lactamases
- Thin peptidoglycan wall |
|
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Term
| What is the analogous feature to LPS (gram negative), in gram positive bacteria? |
|
Definition
| Lipoteichoic acid- Lipid portion to induce TNF and IL-1 (similar to lipid A) and Acid as major surface antigen (similar to O antigen). |
|
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Term
| What is the function of a bacterial spore and what organisms make them? |
|
Definition
- Keratin-like coats composed of dipicolinic acid that provide resistance to dehydration, heat and chemicals.
- Clostridium (anaerobe) and Bacillus (aerobe) |
|
|
Term
What is the function of each of the following bacterial components?
1) Peptidoglycan
2) Cell wall
3) Periplasm
4) Capsule
5) Spore
6) Pilus
7) Glycocalyx |
|
Definition
1) Rigid support and resistance against osmotic pressure (sugar backbone with cross-linked peptide side chains)
2) Major surface antigen
3) Site in gram negatives between outer and inner membranes, where hydrolytic enzymes like beta lactamases are housed.
4) Anti-phagocytic (polysaccharide- except for Bacillus anthracis, which contains D-glutamate)
5) Keratin-like coats composed of dipicolinic acid that resist dehydration, head and chemicals
6) Adhesion to bacterial cell surface (conjugation)
7) Adhesion to surfaces like catheters (Polysaccharide) |
|
|
Term
| What are the gram positive cocci and bacilli? |
|
Definition
1) Cocci
- Staph (aureus, epidermitus, saprophyticus)
- Strep (group A, agalactiae, bovis, pneumoniae, veridans)
2) Bacilli
- Clostridium
- Corynbacterium
- Bacillus
- Listeria
- Mycobacterium (acid fast) |
|
|
Term
| What are the gram positive organisms that have a "branching and filamentous" structure? |
|
Definition
1) Nocardia (aerobic and acid fast)
2) Actinomyces (anaerobic) |
|
|
Term
Which of the following lacks a cell wall?
1) Mycobacteria
2) Mycoplasma
3) Chlamydia
4) Straph
5) Brucella |
|
Definition
| 2) Mycoplasma is the only one- they have sterols instead |
|
|
Term
| What are the spirochetes? |
|
Definition
Gram negatives that are seen by dark field microscopy
1) Leptospira
2) Treponema
3) Borrelia
- Burgdorferi
- Recorenthis |
|
|
Term
| How is the cell wall of mycobacterial species unique? |
|
Definition
| Acid fast staining because of mycolic acid (high lipid content). |
|
|
Term
Which of the following is NOT an enteric organism?
1) E. coli
2) Haemophilus
3) Salmonella
4) Shigella
5) Serratia
6) Bacteroides |
|
Definition
| 2- Gram negative, pleomorphic organism that requires chocolate agar with factor X (Hematin) and V (NAD+) to grow (fastidious) |
|
|
Term
| Which bugs do not gram stain well and why? |
|
Definition
These Rascals May Microscopically Lack Color
1) Treponema: too thin (DFM and antibody staining)
2) Rickettsia (intracellular parasite)
3) Mycobacterium (Mycoloic acid)
4) Mycoplasma (no cell wall-sterols)
5) Legionella (Silver stain)
6) Chlamydia (intracellular parasite; lacks muramic acid in cell wall) |
|
|
Term
Why might you use each of the following special stains?
1) Giemsa
2) PAS (periodic acid schiff)
3) Ziehl-Neelsen (carbol fuchsin)
4) India ink
5) Silver stain |
|
Definition
1) Borrelia, Plasmodium, Trypanosome, Chlamydia
2) Stains glycogen mucopolysaccharides- Whipple's disease (Tropheryma whippelii)
3) Acid-fast organisms
4) Cryptococcus neoformans (mucicarmine can also be used to stain thick polysaccharide capsule red)
5) Fungi (e.g. Pneuomocystits); Legionella |
|
|
Term
A patient with abdominal pain, diarrhea, weight loss and joint pain has a duodenal endoscopy, which reveals presence of organisms that are PAS-positive.
What is going on? |
|
Definition
Whipple's disease from Tropheryma whippleii
PAS stains mucopolysaccharide and glycogen
PASs the Sugar |
|
|
Term
How might you culture each of the following organisms?
1) H. influenzae
2) Neiserria species
3) B. pertussis
4) C. diptheriae
5) M. tuberculosis
6) M. pnneumoniae
7) Lactose-fermenting enterics
8) Legionella
9) Fungi |
|
Definition
1) Chocolate agar with factor V (NAD+) and X (hematin)
2) Thayer Martin (VPN- Vancomycin (gram +), Polymyxin
(Gram-negative), Nysatin (Fungi)
3) Bordet-Gengou (potato) agar
4) Tellurite plate, Loffler's media
5) Lowenstein-Jensen agar (also acid fast)
6) Eaton's agar
7) MacConkey agar (pink colonies)
**E coli also grown and eosin-methylene blue (EMB) as green colonies with metallic sheen**
8) Charcoal yeast with cysteine and iron- stain with silver stain
9) Sabouraud' s agar |
|
|
Term
What organisms would grow on the following media?
1) Thayer Martin plates
2) MacConkey agar
3) Eaton's agar
4) Tellurite plates with Loffler's media
5) Chocolate agar with NAD+ and Hematin |
|
Definition
1) VPN plates with vancomycin (gram positives), Polymyxin (gram negatives), Nystatin (fungi)
- N. meningiditis and N. gonorrhea
2) Lactose-fermenting enterics like E.coli and Klebsiella grow as pink colonies
- E. coli can also be grown on eosin-methylene blue (EMB) as green colonies with metallic sheen
3) M. pneumoniae
4) C. diptheriae
5) H. influenzae (factors V and X) |
|
|
Term
What organisms would grow on the following media?
1) Lowenstein-jensen agar
2) Charcoal yeast with cysteine and iron
3) Eaton's agar
4) Tellurite plates with Loffler's media
5) Bordet-Gengou (potato) plates
6) Sabouraud's agar |
|
Definition
1) M. tuberculosis
2) Legionella (silver stain)
3) Mycoplasma pneumoniae
4) C. diptheriae
5) B. pertussis
6) Fungi (silver stain) |
|
|
Term
| What are the obligate aerobes? |
|
Definition
Nagging Pests Must Breathe
- O2-dependent system to generate ATP
1) Nocardia (weakly acid fast)
2) Pseudomonas
3) Mycobacterium tuburculosis
4) Bacillus |
|
|
Term
| Which anaerobic gram negative organism is found in burn wounds, nosocomial pneumonia and pneumonia in CF? |
|
Definition
P. AERuginosa is an AERobe found in burns, nosocomial pneumonia and CF pneumonia.
**Staph is also seen in CF** |
|
|
Term
| What are the obligate anaerobic organisms? |
|
Definition
Anaerobes Can't Breathe Air
- Lack catalase and/or SOD and are therefore succeptible to oxidative damage.
- Foul-smelling (short-chain fatty acids), difficult to culture and produce gas (CO2 and H2) in tissue.
1) Clostridium
2) Bacteroides
3) Actinomyces |
|
|
Term
| Where are anaerobic bacteria typically found and what glass of antibiotics are completely ineffective against them? |
|
Definition
Can't Breathe Air (Clostridium, Bacteroides, Actinomyces)
1) Normally in GI tract and can be pathogenic elsewhere
2) Aminoglycosides (GNATS), which inhibit the initiation complex formation, but require O2 to enter cells.
- Gentamycin
- Neomycin
- Amikacin
- Tobramycin
- Streptomycin |
|
|
Term
| What are the obligate and facultative intracellular bugs? |
|
Definition
1) Obligate stay inside when it is Really Cold
- Rickettsia
- Chlamydia
2) Some Nasty Bugs May Liver FacultativeLY
- Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis. |
|
|
Term
| What is the meaning of a positive "quellung" reaction and what organisms must cause this to occur? |
|
Definition
1) Capsule swells when anti-capsular antisera is added
- Capsules are anti-phagocytic virulence factors and when conjugated with protein, they serve as antigens in vaccines for S. pneumo, H. influenzae and N. meningitis
**Found in asplenic individuals**
2) SHiN SKiS (group B)
- Strep (group B)
- Haemophilus
- Neisseria meningitidis,
- Salmonella
- Klebsiella pneumonia
- Strep pneumo |
|
|
Term
| What are the major catalase positive organisms and what is the relevance of this feature? |
|
Definition
Catalase degrades H2O2 before it can be converted to microbicidal products by MPO
**Patients with CGD (low NADPH oxidase) get these organisms, because they degrade what little H2O2 is left**
PLACESS for your CATs
1) Pseudomonas
2) Listeria
3) Aspergillus
4) Candida
5) E. coli
6) S. aureus
7) Serratia |
|
|
Term
| What organisms are patients with CGF particularly susceptible to? |
|
Definition
Lacking NADPH oxidase, so no respiratory birst of H2O2.
Catalase positive organisms will degrade what little is left over.
PLACESS for your CATs
1) Pseudomonas
2) Listeria
3) Aspergillus
4) Candida
5) E. coli
6) S. aureus
7) Serratia |
|
|
Term
| Why would a vaccine composed of a polysaccharide antigen alone, without a protein conjugate, be ineffective? |
|
Definition
It would not be recognized and presented by T cells to B cells, causing inadequate class-switching.
Need protein + Polysaccharide antigen
1) Pneuomovax (group B)
2) H. influenza type B
3) Menngococcal
Other encapsulated organisms include Klebsiella pneumoniae and Salmonella (SHiN SKins) |
|
|
Term
| What are the Urease-positive organisms and what is the relevance of this? |
|
Definition
Urease splitting organisms neutralize urea to ammonia, which can alkalanize or at least neutralize urine, predisposing to struvite crystal formation (magnesium ammonium phosphate).
CHuck norris hates PUNKSS
1) Cryptococcus
2) H. pylori
3) Proteus
4) Ureaplasma
5) Nocardia
6) Klebsiella
7) S. epidermidis
8) S. saphrophyticus |
|
|
Term
| What bacteria produce pigments (Yellow, Green, Red, ect)? |
|
Definition
1) Actinomyces israelii (branching, filamentous anaerobe)= yellow "sulfur" granules which are a mass of filaments
2) P. aeruginosa (gram negative, oxidase + aerobe)= blue-green
3) Serratia marescens= Red (like Maraschino cherries) |
|
|
Term
What bacteria produce each of the following virulence factors and what do they do?
1) Protein A
2) IgA protease
3) M protein |
|
Definition
1) S. aureus (gram +, catalase + coagulase +)
- Binds Fc region of Ig and prevents opsonization and phagocytosis
2) Encapsulated organisms following splnectomy (S. pneumo. H. influenza type B and Neisesria (SHiN)
- Cleaves IgA (IL-5) and prevents mucosal immunity.
3) Group A strep
- Prevents phagocytosis |
|
|
Term
| What are the primary differences between exotoxins and endotoxins? |
|
Definition
1) Exotoxins (Tetanus, Botulism, Diphtheria)
- Polypeptides secreted from cells in gram + or gram - organisms
- Genes found on plasmids or on bacteriophage, with high toxicity and antigenicity
- Toxoids are used as vaccines
2) Endotoxins (Meningococemia, and gram negative sepsis)
- LPS (genes on bacterial chromosome) released during cellular lysis, with low toxicity, producing fever and shock
- Heat stable and Induces TNF and IL-1, but is poorly antigenic
- No available vaccines (no toxoids) |
|
|
Term
| What bugs produce exotoxins that inhibit protein synthesis? |
|
Definition
1) C. diphtheriae: Diphtheria toxin ADP-ribosylates/inactivates EF-2 and causes pharyngitis and pseudomembranes in the throat
2) Pseudomonas aeruginosa: Exotoxin A ADP-ribosylates/inhibits EF-2 and induces host cell death
3) Shigella: Shiga toxin (ST) inactivates 60S ribosome by cleaving rRNA, causing GI mucosal damage and dysentery
- Can enhance cytokine release and cause HUS as well
4) EHEC (O157: H7): Shiga-like toxin (SLT) also inactivates 60S ribosome by cleaving rRNA and can cause HUS.
- UNLIKE Shigella, EHEC does not invade host cells usually |
|
|
Term
| What bugs produce exotoxins that increase fluid secretion? |
|
Definition
1) ETEC produces
- heat-labile toxin (LT) ADP-ribosylates and over-activates AC (increase cAMP) and increases Cl- secretion in gut with H2O efflux
- heat stable toxin (ST) that over-activates GC (cGMP) and decreases NaCl/water reabsorption in gut
2) Y. enterocolitica: Produces ST toxin similar to ETEC, but is invasive and causes dysentery
3) Bacillus anthracis makes Edema factor that mimics AC, causing edematous borders of black eschar in cutaneous anthrax
4) V. cholerae produces Cholera toxin, which ADP-ribosylates Gs and causes constitutive activation (AC/cAMP), causing "rice water diarrhea" |
|
|
Term
| Which toxins are similar to the LT and ST toxins of ETEC, respectively? |
|
Definition
1) LT: ADP-ribosylation and over-activation of AC/cAMP, causing Cl- secretion in gut and water efflux (watery diarrhea)
- V. cholerae is very similar, and acts of Gs/AC/cAMP arch, producing rice-water diarrhea
- Bacillus anthracis also over-activates AC with edema fator
2) ST: Over-activate GC/cGMP arch, decreasing NaCl reabsorption in gut and preventing H2O reabsorption as well (watery diarrhea)
- Y. enterocolitica also produces ST, but causes bloody diarrhea, because it is invasive |
|
|
Term
| Which toxins inactivate Elongation factor 2 and what are the effects of doing so? |
|
Definition
Protein synthesis inhibitors
1) Corynbacterium diptheriae
- Produces ADP-ribosylating toxin that causes pharyngitis and throat pseudomembranes
2) Pseudomonas aeruginosa
- Produces Exotoxin A which ADP-ribosylates and inactivates EF-2, leading to host cell death. |
|
|
Term
| Which exotoxins are ADP rbosylating A-B toxins? |
|
Definition
C. diptheriae, P. aeruginosa, ETEC, B. pertussis
B (binding) component binds to host cell surface receptor, enabling endocytosis; A (active) component attaches ADP-ribosyl to disrupt host cell proteins.
1) C. diptheriae and P. aeruginosa make Cholera and Exotoxin A, respectively, which both inactivate EF-2
2) ETEC makes LT that over-activates AC/cAMP, causing Cl- secretion in gut and water efflux (watery diarrhea)
3) V. cholerae makes Cholera toxin, which over-activates AC similar to ETEC LT
4) B. pertussis makes Pertussis toxin, which over-activates AC/cAMP by disabling Gi, impairing phagocytosis to permit survival |
|
|
Term
Child presents with coughing on expiration and strange "whooping" sound on inspiration.
What is the exotoxin responsible for these symptoms? |
|
Definition
Whooping Cough from B. pertussis (pleomorphic gram negative)
Pertussis Toxin ADP-ribosylates and inactives Gi, leading to over-activation of AC/cAMP and preventing phagocytosis (permitting survival) |
|
|
Term
| Which exotoxins act by inhibiting neurotransmitter release? |
|
Definition
Tetanus- rigid (GABA/glycine)
Botulinum- flaccid (ACh)
1) Clostridium tetani produces Tetanospasmin
- cleaves SNARE protein and prevents release of GABA/glycine in spinal chord
- Muscle rigidity and "lock-jaw"
2) C. botulinum produces Botulinum toxin
- Cleaves SNARE protein at NMJ, preventing ACh release
- Flaccid paralysis |
|
|
Term
| Which exotoxins cause cell membrane lysis and what manifestations do they produce? |
|
Definition
1) C. perfringens (non-motile, spore-forming anaerobic gram negative bacillus)
- Alpha toxin acts as phospholipase that causes myonecrosis ("gas gangrene") and hemolysis ("double zone" on blood agar)
2) S. pyogenes (Group A strep, beta hemolytic)
- Produces streptolysin O, which lyses RBCs
- Use ASO antibodies to diagnose rheumatic fever (NOT the same of post-streptococcal GN) |
|
|
Term
| What exotoxins act as super-antigens to produce toxic shock syndrome? |
|
Definition
Both toxins bring MHC II and TCR in proximity to cause overwhelming release of IFN-y and IL-2 leading to shock.
1) Strep pyogenes (group A): Exotoxin A causes fever, rash and shock (Scarlett fever)
2) Staph aureus: TSST-1 causes fever, rash, shock
- Other toxins cause scalded skin (exfoliative toxin) and food poisoning (enterotoxin) |
|
|
Term
| How do endotoxins exert their pathological effects? |
|
Definition
Heat stable LPS (lipid A portion) found in outer membrane of gram negative bacteria
Macrophages (fever and necrosis), Complement (neutrophils, hypotension and edema) and Factor X (DIC)
1) Activates macrophages which produce
- IL-1 (fever)
- TNF (fever and hemorrhagic tissue necrosis)
- NO (hypotension/shock)
2) Activates complement (alternative pathway)
- C3a (hypotension, edema)
- C5a (neutrophil chemotaxis)
3) Activates Hageman factor (X)
- Coagulation cascade- DIC |
|
|
Term
| What are the 4 phases of the bacterial growth curve? |
|
Definition
1) Lag- metabolic activity without division
2) Exponential/log- rapid division.
- Penicillins and cephalosporins act here as peptidoglycan is being made
3) Stationary- nutrient depletion slows growth
- Spore formation may occur here for preservation
4) Death- prolonged nutrient depletion and buildup of waste products |
|
|
Term
| What are the 4 methods of genetic exchange exploited by bacteria? |
|
Definition
TCTT
1) Transformation
- Take DNA up from environment ("competence")
- SHiN bacteria (S. pneumo B, H. influenzae, Neisseria)
2) Conjugation
- F+ plasmid (containing genes required for conjugation) is replicated and transferred to F- cell through pilus (ONLY plasmid genes, not chromosomal)
- If F+ DNA gets incorporated into bacterial chromosomal DNA (Hfr cell), it can be transferred to F- cell with flanking chromosomal DNA
3) Transposition
- DNA segment "jumps" from one location to another (plasmid to chromosome or vice versa)
- Excision of plasmid may include flanking chromosomal DNA as well
4) Transduction
- Generalized: "Packaging event" where lytic phage infects bacterium, cleaves DNA and synthesizes viral proteins, but takes bacterial DNA with it in its capsid to next host.
- Specific: "Excision event" where Lysogenic phage infects bacterium and incorporates DNA into bacterial chromosome, so when phage DNA is excised, bacterial DNA is taken with it to new host. |
|
|
Term
| Which bacterial toxins are encoded in lyogenic bacteriophages? |
|
Definition
These are specialized, transduction systems (exchange of bacterial DNA between bacteria) where viral DNA is incorporated into bacterial DNA, and then excised and taken in viral capsid to next host.
ABCDE
1) shigA-like toxin (from EHEC)
2) Botulinum toxin (C. botulinum)
3) Cholera toxin
4) Diphtheria toxin
5) Erythrogenic toxin from strep pyogenes |
|
|
Term
The following are descriptions of gram (+) bacteria. Which bugs could fit the following?
1) Catalase + Cocci
2) Anaerobic spore-forming bacilli
3) Aerobic bacilli
4) Branching filaments
5) Non-spore forming bacilli |
|
Definition
1) Staph
- Coagulase += S. aureus
- Coagulase - = S. epidermitis (novobiocin sensitive) or S saphrophyticus (novobiocin resistent)
2) Clostridium species- all are mobile except C. perfringens
3) Bacillus anthracis (non-motile) or cereus (motile)
4) Nocardia (aerobic and weak acid-fast) or Actinomyces (anerobic)
5) Listeria (motile) or C. diptheriae (non-motile) |
|
|
Term
The following are descriptions of clusters of gram (+) cocci that are catalase negative. Which bugs could fit the following?
1) Alpha hemolytic (green)
2) Beta hemolytic (clear)
3) Non (gamma) hemolytic |
|
Definition
All grow purple/blue on gram stain (positive)
1) S. pneumoniae (encapsulated-optochin sensitive) or S. veridans (optochin resistant)
2) Group A Strep pyogenes (Bacitracin sensitive) or Group B Strep. agalactiae (Bacitracin resistant)
3) Enterococcus (grows at 6.5% NaCl) or Group D Strep Bovis |
|
|
Term
What is the utility of each of the following antibiotics in diagnosing gram positive bacterial infections?
1) Novobiocin
2) Optochin
3) Bacitracin |
|
Definition
1) Tell between Staph epidermidis (sensitive) and Staph saprophyticus (resistant)
2) Tell between Strep pnuemoniae (sensitive) and Strep viridans (resistant)
3) Tell between Group A strep pyogenes (sensitive) and Group B strep agalactiae (resistant) |
|
|
Term
Which gram positive bacteria would form a green ring around colonies on blood agar?
What about clear area of hemolysis? |
|
Definition
1) Alpha hemolysis
- Strep pneumoniae (Optochin sensitive)
- Strep viridans (mutans and intermedians- Optochin resistant)
2) Beta hemolysis
- Group A strep (bacitracin sensitive)
- Group B strep agalactiae (bacitracin resistant)
- Staph aureus
- Listeria monocytogenes (neonatal meningitis) |
|
|
Term
Gram stain reveals gram + cocci in clusters that are catalase + and coagulase +
What are the major virulence factor(s) of this organism and what are the typical manifestations of infection with it? |
|
Definition
Staph aureus
1) Virulence factors
- Protein A: binds Fc-IgG and prevents complement fixation and phagocytosis
- TSST-1: superantigen that binds MHC II and T-cell receptors (polyclonal T-cell activation)
- Enterotoxin (food poisoning)
- Exfoliatoxin (scalded skin syndrome)
2) Disease
- Inflammatory disease: skin infections, organ abscesses and pneumonia
- Toxic Shock Syndrome (TSST-1)
- Scalded skin (exfoliatoxin)
- Nosocomial and CA MRSA that is beta-lactam resistant (altered PBP) |
|
|
Term
Patient with indwelling catheter prevents with cellulitis infection.
Gram stain reveals clusters of gram + cocci
What is the most likely cause of the cellulitis? |
|
Definition
Staph epidermidis (novobiocin sensitive, coagulase -)
- Common on prosthetic devices and IV catheters (biofilm)
- May contaminate blood cultures (normal part of skin flora) |
|
|
Term
Gram stain reveals lancet shaped gram (+) diplococci that are catalase negative.
What are the major virulence factors and diseases associated with this organism? |
|
Definition
S. pneumoniae (Optochin sensitive)
1) Capsule, M protein and IgA protease
2) Disease
- Most common cause of MOPS (Meningitis, Otitis media in children, Pneumonia, Sinusitis)
- Rusty sputum, sepsis in sickle cell anemia and splenectomy |
|
|
Term
| What is the most common cause of death in patients with sickle cell anemia? |
|
Definition
| Strep pneumonia sepsis (asplenia) |
|
|
Term
Gram stain reveals gram +, catalase - cocci that are resistant to Optochin.
What are the most common causes of dental caries and bacterial endocarditis that would also fit these characteristics? |
|
Definition
Both will be Viridans streptococci
1) Dental caries- Strep mutans
2) Bacterial endocarditis- Strep sanguis (damaged valve) |
|
|
Term
Gram stain reveals gram + catalase -, beta-hemolytic cocci that are sensitive to Bacitracin.
What are the virulence factors and diseases associated with this organism? |
|
Definition
Group A Strep pyogenes- recent infection detected by ASO titer
1) Virulence
- M protein (enhance host response but lead to Rheumatic fever)
- Streptolysin O (degrades membranes and contributes to hemolysis)
- Exotoxin A/B/C (Toxic shock-like syndrome and Scarlett fever)
2) Diseases
- Pyogenic: pharyngitis, cellulitis, impetigo
- Toxigenic: Scarlet fever, toxic shock-like syndrome
- Immunologic- Rheumatic fever, acute GN
"PHaryngitis can result in rheumatic PHever and glomerulonePHritis" |
|
|
Term
| What is the basic Jones Criteria for Rheumatic Fever? |
|
Definition
1) Major
No "rheum" for SPECCulations
- Sub-q nodules
- Polyarthritis
- Erythema marginatum
- Choreaform movements
- Carditis
2) Minor
- ESR
- Recent strep infection
- Arthralgia |
|
|
Term
Which Bacitracin-resistant, beta hemolytic colonies of gram positive bacteria colonize the vagina?
What disease do they cause and how? |
|
Definition
Strep agalactiae hit the BABIES, must screen pregnant women at 35-37 weeks (may need intra-partum penicillin prophylaxis)
**produce CAMP factor, which increases hemolysis area relative to S aureus on blood agar**
1) Pneumonia
2) Meningitis
3) Sepsis |
|
|
Term
| What are the "Lancefield group" bacteria and what conditions do the give rise to? |
|
Definition
Group D streptococci (based on C carbohydrate differences in bacterial cell wall).
These are non-hemolytic, catalase negative cocci
1) Enterococcus faecalis and faecium (grow at 6.5% NaCl)
- VRE is important for nosocomial infections
- cause UTI and sub-acute endocarditis
2) Strep bovis (does not grow at 6.5%)
- colonize gut
- bacteremia and subacute endocarditis in colon cancer patients |
|
|
Term
Patient presents with pharyngitis and dysphagia from grayish-white membranes in the throat with accompanying lymphadenopathy
Gram stain reveals club-shaped, gram positive rods that grow on tellurite agar and an Elek test is positive.
Labs also reveal metachromatic (blue and red) granules inside the organisms.
What is the pathophysiology underlying this condition? |
|
Definition
C. diptheriae (Elek test is for toxin): Toxoid vaccine is available!
- ADP-ribosylating exotoxin inactivates EF-2 and inhibits protein synthesis
ABCDEFG:
A- ADP-ribosylates
B- Beta-prophage
C- Corynebacterium
D- Diptheria
E- EF-2
G- Granules |
|
|
Term
| Which bacteria produce spores? |
|
Definition
Spores formed when nutrients are poor during stationary phase of growth (gotta autoclave).
Dipicolinic acid resists heat and chemicals, and spores are non-metabolic
B. anthracis and C. perfringens are soil bacteria
1) Clostridium (anaerobes)
2) Bacillus (aerobes) |
|
|
Term
| What do each of the Clostridial exotoxins do? |
|
Definition
Anaerobic, gram positive rods that are motile (except Perfringens)
1) C. tetani: Tetanospasmin
- prevents GABA/glycine release from Renshaw cells in spinal cord, producing rigid paralysis
2) C botulinum: Pre-formed, LT
- Inhibits ACh release at NMJ
- Flaccid paralysis (adults eat pre-formed toxin and babies eat spores in honey)
3) C difficile: Toxin A (enterotoxin) and Toxin B (cytotoxin)
**Caused by Clindamycin or Ampicillin use: diagnose in stool**
- Toxin A binds intestinal brush border
- Toxin B destroys cytoskeletal structure of enterocytes, causing pseudomembranous colitis
- DIARRHEA
4) C. perfringens (soil): alpha toxin (Lecithinase- phospholipase)
- Myonecrosis (gas gangrene) and Hemolysis |
|
|
Term
| How do you treat the nosocomimal diarrheal infection caused by Clindamycin/Ampicillin use? |
|
Definition
C. dif diarrhea
- Metranidazole or oral Vancomyocin |
|
|
Term
| Patient presents with black eschar necrotic lesions that are surrounded by edematous rings. What pulmonary manifestations can this organism cause? |
|
Definition
Cutaneous anthrax from B. anthracis (aerobic, gram positive rod that produces spores and has D-glutamate capsule)
1) Cutaneous anthrax (contact) caused by lethal factor (cell death) and edema factor (mimics AC/cAMP)
2) Causes pulmonary anthrax when inhaled (Woolsorters' disease if they are in wool) with flu-like symptoms, pulmonary hemorrhage, mediastinitis and shock. |
|
|
Term
| Which is the ONLY bacteria with a D-glutamate capsule? |
|
Definition
| Bacillus anthracis: pulmonary or cutaneous anthrax with Lethal factor and Edema factor |
|
|
Term
Why should a pregnant women avoid eating un-pasteruized milk/cheese products and deli meats?
What is the pathogenesis and how do you treat? |
|
Definition
Listeria monocytogenes infection is subject to vaginal transmission during birth (Neonatal meningitis)
- Gram positive, non-spore-forming rod with tumbling motility (actin rockets).
1) Causes Amnionitis, Granulomatis infantiseptica, Neonatal meningitis (or meningitis in immunocompromised adults)
2) Usually self-limited, but Ampicillin in infants and immunocompromised patients (given as empirical prophylaxis for elderly) |
|
|
Term
| How can you differentiate between the two gram-psotive rods that form branching filaments that resemble fungi? How do their treatments differ? |
|
Definition
1) Bugs
- Actinomyces (oral/facial abscesses that drain through sinuses and skin) is anaerobic and normally found in oral
**YELLOW sulfur granules in sinus tracts**
- Nocardia asteroides (Pulmonary infection in immunocompromised) is weakly acid-fast and aerobic
2) SNAP
- Sulfa for Nocardia
- Actinomycse needs Penicillin |
|
|
Term
| Describe the basic pathophysiology of M. tuberculosis infection. |
|
Definition
M. tuberculosis is non-motile, aerobic, gram positive rod that is acid-fast.
1) Primary infection in non-immune host
- Spreads to hilar lymph nodes and Ghon focus in lower lobes (Ghon complex)
- Can heal by fibrosis (PPD positive), progress (HIV, malnutrition), spread systemically (Miliary), or lie dormant in lymphatic and organs.
2) Secondary infection (hyper-sensitized adult or reactivation)
- Fibvrocaseous cavitary lesion in the upper lobes
- Extrapulmonary TB (CNS, Vertebral body, Renal, GI and Lymphadenitis) |
|
|
Term
| What does a positive PPD test mean? |
|
Definition
Current infection, Past exposure or BCG vaccinated
Type IV DTR |
|
|
Term
| What are the major mycobacterium that cause disease? |
|
Definition
1) M. tuberculosis (fever, night sweats, hemoptysis and weight loss)
2) M. kansasii (pulmonary TB-like symptoms)
3) M. avium-intracellulare (MDR, disseminated disease in AIDS)
- requires Azithromycin prophylaxis
4) M. leprae
- Lepromatous (most severe with Th2 response)
- Tuberculoid (less severe with Th1 response) |
|
|
Term
| What is the difference between Lepromatous and Tuberculoid Leprosy (Hansen's disease)? |
|
Definition
Both caused by M. leprae, an acid-fast bacillus that likes cool temperatures and cannot be grown in vitro (US Armadillos)
1) Lepromatous
- "Leonine facies": lost eyebrows, Nasal collapse, Lumpy earlobes
- Diffuse skin involvement with humoral Th2 response (SEVERE)
- Communicative
2) Tuberculoid
- Limited to few hypoesthetic skin plaques, with high Th1 response
- Less severe than Lepromatous |
|
|
Term
Which gram negative bacteria fit each of the following descriptions (may be more than 1)
1) Cocci
2) Pleomorphic aerobe
3) Non lactose-fermenter, oxidase negative
4) fast lactose-fermenter
5) Silver impregnation required
6) Non lactose-fermenter, oxidase positive
7) Oxidase +, comma shaped
8) Slow lactose-fermenter |
|
Definition
1) Nesseria gonorrhea (glucose) or meningitis (glucose + maltose), or M. catarhalis (oxidase +)
2) Brucella
3) Salmonella (H2S split and motile), Shigella (No H2S split and non-motile), Proteus (urease splitter)
4) Klebsiella, Enterobacter and E coli (indole positive)
5) Bordatella hensleae
6) Pseudomonas aeruginosa (blue-green) and V. cholerae (glucose), H. pylori (urease)
7) C. jejuni (grows at 42) and V. cholerae (grows in alkaline media)
8) Citrobacter, Serattia (red) |
|
|
Term
| What are the gram negative lactose-fermenting bacteria? |
|
Definition
Lactose is KEE and test with MacConKEE'S
1) Citrobacter (slow)
2) Klebsiella (fast)
3) E. coli (fast)- produces beta-galactosidase (lactose to glucose and galactose)
4) Enterobacter (fast)
5) Serratia (slow) |
|
|
Term
| Why are gram-negative bugs resistant to penicillin G and vancomycin? What PCN derivative can be used instead? |
|
Definition
Resistant Outer Membrane.
May be susceptible to Ampicillin |
|
|
Term
| What are the major differences between the Neisseria Gonnococci and Meningococci? |
|
Definition
Both produce IgA protease and ferment glucose
1) Gonococci (Ceftriaxone)
- No capsule
- No maltose fermentation
- No vaccine (rapid antigenic variation of pilus proteins)
- Sexually transmitted
- Gonorrhea, septic arthritis, neonatal conjunctivitis, PID and Fitz-Hugh-Curtis syndrome
2) Meningococci
- Polysaccharide capsule
- Glucose + Maltose
- Vaccine (none for type B)
- Respiratory ad oral secretions
- Meningococcemia and Meningitis, Waterhouse Friderichsen syndrome (adrenal hemorrhage)
- Rifampin, Ceftriaxone and Cipro prophylaxis to close contacts
- Treat with Ceftriaxone and penicillin G |
|
|
Term
| How do the treatments for N. gonorrhea and N. meningitis differ? |
|
Definition
1) Gonorrhea= Ceftriaxone
2) Meningitis= Ceftriaxone + PCN G
- Prophylaxis for close contacts with Rifampin, Ceftriaxone or Cipro |
|
|
Term
| What is the pathophysiology/treatment of the fastidious gram negative bacteria that grows on chocolate agar with factor V and X? |
|
Definition
DOES NOT CAUSE FLU
HaEMOPhilus influenza is most invasive (type B capsule) and produces IgA
1) Epiglottitis (red), Meningitis, Otitis media, Pneumoniae
2) Treat meningitis with Ceftriaxone
- Rifampin prophylaxis for close contacts (like N. meningitis)
- Give vaccine (type B capsule conjugated to diphtheria toxoid or other protein) between 2-18 months |
|
|
Term
What are the major diseases caused by the pleomorphic gram negative bacteria that requires cysteine and iron to grow on charcoal yeast agar and silver stain to visualize?
How do you treat them? |
|
Definition
Legionella pneumophila- Aerosol transmission from environmental water source, with NO person-person transmission.
1) Legionnaires disease= severe pneumonia and fever
2) Pontiac fever= mild flulike illness
Treat with Erythromycin |
|
|
Term
| What are the most common diseases associated with the oxidase positive, gram negative rod that appears as blue-green from procyanin pigmentation? |
|
Definition
PSEUDOmonas aeruginosa- Wound and Burn infections.
Water connection and treated with aminoglycoside + extended-spectrum PCN
1) Pneumonia
2) Sepsis (black lesions on skin)
3) External otitis (swimmer's ear)
- can be malignant in diabetics
4) UTI
5) Drug use and Diabetic Osteomyelitis
6) hot tub folliculitis |
|
|
Term
| What are the virulence factors and treatment of the most common infection found in burn victims. |
|
Definition
Pseudomonas aeruginosa
1) Endotoxin (fever, shock) and Exotoxin A (similar to Diptheria toxin, where AC/cAMP over-activity and inhibition of protein synthesis causes cell death)
2) Treat with Aminoglycoside (GNATS) + extended spectrum PCN (Piperacillin or Ticarcillin) |
|
|
Term
Which of the following would be an appropriate treatment regimen for Pseudomonas infection in external otitis?
1) Gentamycin + Doxirubicin
2) Tobramycin + Piperacillin
3) Ceftriaxone + Neomycin
4) Erythromycin + Ticarcillin
5) Amikacin + Clindamycin |
|
Definition
2- Want Aminoglycoside + extended-spectrum PCN
PSEUDO (pneumonia, sepsis, external otitis, UTI, drug use, diabetic osteomyelitis) |
|
|
Term
| What are the major virulence factors and their accompanying disease etiologies shared by all E. coli strains? |
|
Definition
1) Fimbriae- Cystitis and Pyelonephritis
2) K capsule- Pneumonia, Neonatal meningitis
3) LPS endotoxin- Septic shock |
|
|
Term
Which E. coli is described by each of the following presentation and what is its toxin and mechanism?
1) Dysentery
2) Traveler's diarrhea (watery)
3) Pediatric diarrhea
4) Anemia, thrombocytopenia and acute renal failure |
|
Definition
1) EIEC: Invades intestinal mucosa and causes necrosis and inflammation (similar to Shigella presentation)
2) ETEC: Labile cAMP toxin/stable cGMP toxin without inflammation/invasion
3) EPEC: no toxin. Adheres to apical surface and flattens villi, preventing absorption of nutrients
4) EHEC 0157:H7 serotype
- Produces Shiga-like toxin (60S inhibition via rRNA with NO invasion) and HUS triad
- Endothelium swells and narrows lumen, leading to mechanical hemolysis and reduced renal blood flow; damaged endothelium consumes platelets. |
|
|
Term
Which E. coli does not ferment sorbitol?
Which E. coli cause dysentery? |
|
Definition
1) EHEC 0157:H7
2) EIEC (fecal leukocytes as well) and EHEC (no invasion) |
|
|
Term
| What diseases are caused by the gram negative, rapid lactose-fermenting bacteria that produces mucoid colonies and red currant jelly sputum? |
|
Definition
Klebsiella= Nosocomial UTIs
- Present in intestinal flora and subject to lobar aspiration in alcoholics and diabetics (mucoid colonies arise form abundant polysaccharide capsule)
4 A's
1) Aspiration pneumonia (lobar)
2) Abscess in lungs and heart
3) Alcoholics
4) diAbetics |
|
|
Term
| What are the major differences between Salmonella and Shigella in terms of bacterial pathogenesis and treatment? |
|
Definition
Both are invasive, oxidase negative, gram negative, non-lactose fermenting rods that produce dysentery
1) Salmonella (motile, H2S splitting)
- Flagella that enable hematogenous dissemination and produce a monocytic response
- Antibiotics lengthen symptoms
2) Shigella
- More virulent (fewer required) and propel themselves within cells via actin polymerization
- Antibiotics shorten length of disease |
|
|
Term
Patient presents with rose spots on her abdomen, a bad fever, headache and diarrhea.
Where does this infection lie latent following active infection? |
|
Definition
Salmonella typhi- Typhoid fever
May lie dormant in Gallbladder and cause carrier state.
**Gram negative, flagellated bacteria that does not ferment lactose, but produces H2S** |
|
|
Term
| What is the major bacterial cause of bloody diarrhea in children and what autoimmune disease is it associated with down the line? |
|
Definition
1) C. jejuni- Oxidase +, comma shaped gram negative that grows at 42 degrees and is transmitted fecal-oral (poultry, meat, unpasteurized milk)
2) Antecedent to Guillain-Barre (Molecular mimicry), which is inflammatory demyelination of peripheral nerves and motor fibers of ventral roots, causing symmetric ascending muscle weakness beginning in distal lower extremities. |
|
|
Term
| What bacteria produces profuse "rice-water" diarrhea and how? |
|
Definition
Requires prompt oral rehydration and endemic to developing countries.
Vibrio cholerae: Comma shaped, oxidase (+) gram negative rod that grows in alkaline media
- Cholera toxin ADP-ribosylates and innactivates Gi, leading to over-activation of AC/cAMP and Cl-/water efflux in intestine. |
|
|
Term
| Which bacteria is transmitted from pet feces (puppies), contaminated milk and pork, producing diarrheal outbreaks in daycare centers? |
|
Definition
Y. enterocolitica: Gram-negative rod that is motile at 25 degrees, but NOT at 37 degrees
Causes:
1) Diarrhea
2) Mesenteric adenitis: can mimic Crohn's or appendicitis. |
|
|
Term
What is the cause of gastritis and 90% of duodenal ulcers?
What other conditions is it a risk factor for? Hw do you treat? |
|
Definition
H. pylori- Gram negative rod that is urease positive, and is able to create alkaline environment
1) PUD, Gastric adenocarcinoma and gastric lymphoma
2) Triple therapy (PPi, clarithromycin, amoxxicillin/metronidazole) |
|
|
Term
| What are the spirochetes and how can they be visualized? |
|
Definition
BLT. B is Big
Borellia, Leptospira and Treponema
1) Borellia can be seen with analine dyes (Wright or Giemsa) because it is big
2) Treponema requires DFM |
|
|
Term
Which spirochete causes each of the following?
1) Flulike symptoms, jaundice and photophobia with conjunctivitis in surfers.
2) Erythema chronicum migrans with "bull's eye" red rash, arthralgia and CNS/cardiac effects.
3) Painless chancre progressing to chronic granulomatous disease and ultimately central deafness. |
|
Definition
1) Leptospira interrogans: question mark-shaped bacteria in water contaminated with animal urine
**Can cause Weils disease (icterohemorrhagic leptospirosis), a severe form with jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage and anemia**
2) Borrelia burdorferi- Ixodes tick (also for babesia) of mice and deer
- Treat with doxycyline, ceftriaxone
3) Treponema pallidum- primary, secondary and tertiary forms |
|
|
Term
Patient presents with jaundice, azotemia, fever, hemorrhage and anemia.
The bacteria has to be viewed by dark field microscopy.
What is going on? |
|
Definition
Weil's disease- Leptospira interrogans (water contaminated with animal urine, particularly in tropical surfers)
Severe form with icterohemorrhagic leptospirosis. |
|
|
Term
| What are the 3 stages of Lyme disease? How do you treat? |
|
Definition
B. burdorferi
BAKE a Key Lyme pie: Bell's palsy (bilateral), Arthritis, Kardiac block, Erythema migrans
**Treat with doxycycline, ceftriaxone**
1) Erythema chronicum migrans and flulike symptoms
2) CNS (Bell's palsy, VII nerve) and cardiac (AV nodal block)
3) Chronic monoarthritis and migratory polyarthritis |
|
|
Term
| What are the classic manifestations of primary, secondary and tertiary syphilis? Treatment? |
|
Definition
Treponema pallidum- visualized on DFM and treated with PCN G
1) Painless chancre (localized vasculitis)
2) Disseminated disease (secondary is systemic)
- Constitutional symptoms
- Maculopapular rash (palms and soles)
- Conylomata lata (genital wart)
3) Gummus (chronic granuloma), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis), Argyll robertson pupil |
|
|
Term
| How do you screen/confirm primary, secondary and tertiary syphillus? |
|
Definition
Treat with PCN G: T. pallidum visualized by DFM (primary and secondary)
Primary and Secondary screened with VDRL and confirmed with FTA-ABS
Tertiary is tested for in spinal fluid with VDRL |
|
|
Term
Newborn prsents with saddle nose and deafness.
They have sharp anterior bowing of their left tibia as well as characteristically "notched" incisors and "pegged molars".
What is this? |
|
Definition
Congenital Syphillis
Saber shins, Saddle nose, CNN VIII deafness, Hutchinson's teeth and mulberry molars |
|
|
Term
When/why do you see each of the following in syphilis?
1) Notched incisors
2) Broad-based ataxia with a positive romberg
3) Non-hypertensive stroke and Charcot joints
4) Aortitis
5) Gummas
6) Genital warts |
|
Definition
1) Congenital syphilis
2) Tertiary syphilis (Tabes dorsales= loss of dorsal columns and dorsal roots)
3) Also Tertiary syphilis- degeneration of weight-bearing joints is Charcot's
4) Tertiary syphilis (damage of vasa vasorum)
5) Tertiary syphilis (chronic granulomas)
6) Condyloma lata (secondary syphillus)
4) |
|
|
Term
| What are Argyll robertson pupils? |
|
Definition
| Seen in Tertiary syphilis, where pupils accommodate, but do not react (Prostitute's pupil) |
|
|
Term
| What are the most common causes of "false positive" syphilis screens? |
|
Definition
VDRL test- non-specific antibody that reacts with beef cardiolipin
- Viruses (EBV, hepatitis)
- Drugs
- Rheumatic fever
- Lupus and leprosy |
|
|
Term
Which bacteria is derived from each of the following zoonotic reservoir?
1) Cat scratch
2) Ixodes ticks (deer and mice)
3) Louse
4) Unpasteruized dairy
5) Puppies and livestock
6) Parrots
7) Spores from tick feces and cattle placenta |
|
Definition
1) Catch scratch disease- Bartonella henslei (silver impregnation)
2) Borrelia burdorferi (Lyme's) and Babesia
3) Borellia recurentis (relapsing fever) and Rickettsiae prowazekii (Epidemic typhus)
4) Brucella (undulant fever)
5) C. jejuni (bloody diarrhea)
6) C. psittaci (Psittacosis)
7) Coxiella burnetti (Q fever) |
|
|
Term
Which bacteria is derived from each of the following zoonotic reservoir?
1) Lone star tick
2) Ticks, rabbits, deer fly
3) Animal urine
4) Armadillos
5) Animal bite, cats and dogs
6) Dermacentor tick
7) Flea
8) Flea bite, rodents and prairie dogs |
|
Definition
1) Ehrlichiosis chaffeensis (Ehrlichiosis)
2) Francisella tularesnsis (Tularemia)
3) Leptospira (Leptospirosis)
4) M. leprae (Leprosy)
5) Pasteurella multocida (Cellulitis, osteomyelitis)
6) Rickettsia rickettsii (RMSF)
7) Rickettsia typhus (Endemic typhus)
8) Yersinia pestis (plague) |
|
|
Term
| What organisms are transmitted by ticks and which kind of ticks are associated with each? |
|
Definition
1) Ixodes tick (live on deer and mice)
- B. burdorferi
- Babesia
2) Dermacentor tick
- Rickettsia rickettsii
3) Lone star tick
- Erlichiosis
F. tularensis is also carried on ticks from mice/prairie dogs |
|
|
Term
What bacteria causes a painless "fishy" vaginal odor?
Under the microscope, you notice vaginal epithelial cells covered with bacteria. Treatment? |
|
Definition
I don't have a clue why I smell fish in the vagina garden!
Gardnerella vaginalis: pleomorphic, gram-variable rod that causes vaginosis and present as gray discharge (Clue cells) with fishy smell (associated with Mobiluncus anaerobe)
- Associated with sexual activity, but not an STD (bacterial overgrowth)
- Treat with metronidazole |
|
|
Term
| What are "clue cells" and when do you see them? |
|
Definition
| Vaginal epithelial cells covered in bacteria seen in Gardnerella vaginalis infection (pleomorphic bacteria that produces painless, gray discharge and fishy odor) |
|
|
Term
| Which Rickettsial diseases present with a rash and which do not? |
|
Definition
Treat all with Doxicycline
"Rickettsia on the wRist and Typhus on the Trunk"
1) Rash
- Rickettsia rickettsii (dermacentor tick): rash starts on wrists and ankles, and spreads to trunk, palms and soles of feet (vs, secondary syphilis rash, which starts on soles and palms)
- Endemic typhus (fleas): R. typhi
- Epidemic typhus (louse): R. prowazekii (starts centrally and spreads out, sparing palms and soles)
2) No rash
- Ehrlichiosis (lone star tick): monocytes with berry cluster in cytoplasm (vs. Anaplasmosis: granulocytes with berry cluster in cytoplasm)
- Q fever (Pneumonia presentation) from Coxiella burnetti (spores from tick feces and cattle placenta) |
|
|
Term
Patient presents with headache, fever and rash (vasculitis) that started on his ankles and wrists, but has no spread to his trunk and soles of hands and feet.
What is the vector of this bug and how do you treat? |
|
Definition
R rickettsii- Dermacentor tick and give Doxicycline
If this was R. typhus (Endemic-Typhus/flea or Epidemic- Prowazekii/louse), the rash would start on the trunk |
|
|
Term
|
Definition
Caused by Coxiella burnetii, the only ricketsial species that has no vector, can survive on the outside, produces no rash and has a negative Weil-Felix test.
Q fever looks like a Pneumonia and is caused by inhalation of spores from tick feces or cow placenta. Like all other Ricketsial infections, give doxicycline. |
|
|
Term
| Why might you use a Weil-Felix reaction and what would a positive test mean? |
|
Definition
Mix patient serum with Proteus antigens, which causes Rickettsial antibodies to cross-react to Proteus O antigens and agglutinate on latex base.
1) Diagnose Rickettsial infections (RMSF/ricketsii, Endemic typhus/Typhus, Epidemic typhus/Prowazekii, Ehrlichiosis)
2) Coxiella burnetii will be negative, so a negative test does not rule out Q fever, which would present as pneumonia have inhalation of spores from cow placenta or tick feces. |
|
|
Term
| Which bacterial infection endemic to the east coast presents initially with fever and a rash on the ankles and wrists that spreads to the palms, soles and trunk? |
|
Definition
Rocky mountain spotted fever from R. rickettsii (Dermacentor tick)
Treat with Doxicycline.
Cocksackie virus and Syphillis (secondary) also produce palm/sole rash |
|
|
Term
| Which infections typically can cause a rash on the palms and soles of hands and feet? |
|
Definition
1) RMSF (after spreading from wrists and ankles)
2) Cocksackie virus
3) Syphilis (secondary) |
|
|
Term
| Describe the basic life cycle of a Chlamydial organism. |
|
Definition
Rickettsia and Chlamydia are obligate intracellular bacteria (need coA and NAD+)
Mucosal infections
1) Elementary body (small and dense) is Enfectious form that Enters cells via endocytosis
2) Reticulate body replicates in cell by fission (form seen in tissue culture)
**Cytoplasmic inclusions of multiple EB from RB fission seen on Giemsa or flourescent antibody-stained smear** |
|
|
Term
| What makes the chlamydial cell wall unusual? How do you treat a chlamydial infection? |
|
Definition
1) Lacks muramic acid.
2) Give Azithromycin (one-time treatment) or Doxycycline |
|
|
Term
| What are the major forms of chlamydial infections? |
|
Definition
Diagnose by cytoplasmic RB/EB inclusions with antibody or Giemsa stain and treat with Azithromcyin (once) or Doxi
1) Trachomatis- Reactive arthritis, conjunctivitis, nongonococcal urethritis and PID
- A, B, C: Chronic infection, causes blindness due to follicular conjunctivitis in Africa
- D-K: Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), neonatal conjunctivits
- L1-L3: Lymphogranuloma venerum
2) Pneumoniae- aerosol transfer and atypical pneumonia
3) Psittaci- aerosol transfer and atypical pneumonia (bird reservoir) |
|
|
Term
What C. trachomatis serotypes cause each of the following?
1) Chronic infection, with blindness due to follicular conjunctivitis in Africa
2) Lymphogranuloma venerum
3) Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), neonatal conjunctivits |
|
Definition
ABC= Africa/Blindness/Chronic infection
D-K= everything else
**Neonatal disease can be acquired during passage through infected birth canal**
1) A, B C
2) L1-L3
3) D-K |
|
|
Term
| Why might a neonate present with conjunctivitis, dullness of lower lobes to percussion and a staccato cough? |
|
Definition
Neonatal pneumonia due to Chlamydia trachomatis (D-K serotypes)
**spread by infected birth canal** |
|
|
Term
25 year old patient presents complaining of a non-productive cough. He has been having headaches the past week weeks and on X-ray, you notice a diffuse interstitial infiltrate (looks worse than his symptoms!)
Gram stain reveals nothing, but you grow organisms on Eaton's agar. How should you proceed? |
|
Definition
Sounds like atypical "walking" pneumonia of Mycoplasma pneumoniae (common in patients 30, especially in military and prisons where there are close quarters)
High titer of cold agglutinins (IgM), which agglutinate and lyse RBCs would be helpful as well to confirm.
Treat with Tetracycline or Erythrmoycin (bugs are PCN resistant because they have NO CELL WALL) |
|
|
Term
| Why do PCN antibiotics not work on Mycoplasma bacteria? |
|
Definition
No cell wall! They have cholesterol in their membranes.
PCN drugs inhibit cell wall synthesis.
Give tetracycline or erythromycin instead to treat atypical, walking pneumonia of military personel and prisoners <30 years old. |
|
|
Term
| What are the basic treatments for local and systemic fungal infections? |
|
Definition
Local
- Fluconazole: Inhibit sterol (ergosterol) synthesis by inhibiting P-450 that converts lanosterol to ergosterol
- Ketoconazole: same as fluconazole
Systemic
- Amphotericin B: binds ergosterol and forms membrane pores that allow leakage of electrolytes |
|
|
Term
| What are the major systemic mycoses? |
|
Definition
Dimorphic fungi (all cause pneumonia): cold/room (20) molds and heated/body (37) yeasts (EXCEPT coccidiomycosis, which is Spherule in body tissue)
**may look like TB, but will have NO person:person contact**
1) Histoplasmosis: Hides in macrophages and causes Pneumonia
- Ohio/Mississippi river valley
- Transfered from bird/bat droppings (caves)
2) Blastomycosis
- Broad-based buds from states east of Mississippi river and Central America
- Inflammatory lung disease that can disseminate to skin and bone, forming granulomatous nodules
3) Coccidiomycosis
- Southwestern US, California (San Jaoquin Valley and desert)
- Pneumonia and meningitis and can disseminate to bone and skin.
- Seen following earthquakes, where spores are blown up in dust and become spherules in lungs (filled with endospores)
4) Para-cocciodiomycosis
- Budding yeast with "captain's wheel" formation in Latin America
" Paracoccidio Parasails with the captain's wheel all the way to Latin America" |
|
|
Term
Which dimorphic fungus is described by each of the following? How does their size relate to an RBC?
1) Broad-based budding yeast from Eastern states and central america that causes inflammatory lung disease and can disseminate to skin and bone, forming granulomatous nodules (TB mimic)
2) Hides in macrophages in people people who are exploring caves in Ohio/Mississippi river valley, causing Pneumonia
3) Budding yeast with "captain's wheel" formation in Latin America, causing Pneumonia
4) Cause of pneumonia and meningitis following earthquakes in Southwest/California, surviving in lungs as spherules filled with endospores |
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Definition
All may cause pneumonia due to systemic mycoses. Treat with fluconazole/ketokonazole (local) or Amphoterecin B (systemic)
1) Blastomycosis- same size as RBC
2) Histoplasmosis- smaller than RBC
3) Paracoccidiomycosis- Much larger than RBC
- Rarest and most severe dimorphic fungal infection
4) Coccidiomycosis- much larger than RBC |
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Term
| What are the typical cutaneous mycoses? |
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Definition
1) Tinea versicolor- Malassezia furfur
- Degrades lipids and produces acids that damage melanocytes and cause hypo-pigmented and/or hyper-pigmented patches.
- Occurs in hot, humid weather.
- "Spaghetti and meatball" appearance on KOH prep
Other tinae
2) Tinea pedis (foot)
3) Tinea cruris (groin)
4) Tinea corporis (ringworm, on body)
5) Tinea capitis
- Pruritic lesions with central clearing resembling a ring, caused by dermatophytes (Microsporum, Tirichophyton and Epidermophyton), scalp)
- Mold hyphae in KOH prep, not dimorphic |
|
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Term
| How should you treat a Tinea versicolor infecition? |
|
Definition
Malassezia furfur (degrades lipids and produces acids that damage melanocytes, causing hypo/hyper pigmentation patches in humid, hot weather).
- Topic miconazole, selenium sulfide (Selsun)
- "spaghetti and meatballs" on KOH |
|
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Term
| Which cutaneous mycoses appear as mold hyphae on a KOH prep? |
|
Definition
Tinea pedis (foot), cruris (groin), capitis (head, scalp), corporis (ringworm, on body)
Pruritic lesions with central clearing resembling ring, caused by dermatophytes (Microsporum, Trichophyton, Epidermophyton)
***Tinea versicolor looks like "Spaghetti and meatballs" |
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Term
| What are the 6 major opportunistic fungal infections? |
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Definition
1) Candida
2) Aspergillus fumigatus
3) Cryptococcus neoformans
4) Mucor and Rhizopus spp.
5) Pneumocystis jiroveci
6) Sporothrix schenckii |
|
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Term
| What kinds of opportunistic infections are caused by Candida albicans and how do you treat each? |
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Definition
Vagina= Topical Azole
Oral/esophageal= Fluconazole or Caspofungin
Systemic= Fluconazole, Caspofungin or Amphotericin B
1) Oral and esophageal thrush in immunocompromised (neonates steroids, diabetes, AIDS)
2) Vulvovaginitis (diabetes)
3) Diaper rash
4) Endocarditis in IV drug users (also Staph)
5) Chronic mucotaneous candidiasis (Polyglandular disease with Addison's and hypoparathyroidism)
6) Disseminated |
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Term
Which opportunistic fungi is described by each of the following?
1) Dimorphic yeast with pseudohyphae (budding yeasts at 20 degree temp and germ tubes at 37)
2) 5-10 micron yeasts with wide capsular halos that are grown on Sabouraud's agar and stained with India ink
3) Septate hyphae that branch at 45 degree angles (rarely seen as a conidiophore with fruiting bodies)
4) Irregular broad, non-septate hyphae branching at >90 degree angles
5) Disk-shaped yeast forms on methenamine silver stain of lung tissue
6) Dimorphic, cigar-shaped budding yeast that lives on vegetation and is introduced to human body via trauma (thorn) |
|
Definition
1) Candida albicans
- Local (vaginitis or oral/esophageal thrush)
- Systemic (endocarditis, mucocutaneous, disseminated)
2) Cryptococcus neoformans
- Meningitis (soap bubble lesion) in immunocompromised
- Pigeon poop and soil (inhaled and disseminated)
3) Aspergillus fumigatus
- Invasive in immunocompromised and those with CGD
- Allergic bronchopulmonary aspergillosis with asthma or CF
- Cavities in lung after TB
- Aflatoxins that can cause HCC
- Invasive/disseminated disease
4) Mucormycosis
- Penetrate cribriform plate in Ketoacidotic diabetics and Leukemia patients, causing brain abscesses and cranial nerve involvement.
5) Pneumocystis jiroveci
- Diffuse interstitial, bilateral pneumonia in AIDs
- Diagnosed with lung biopsy or lavage
6) Sporothrix schenkii
-cause local pustules or ulcers with nodules along draining lymphatics |
|
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Term
Patient with cystic fibrosis presents with symptoms consistent with allergic bronchopulmonary infection.
An organism with septate hyphae that branch at 45 degree angles is recovered from lavage fluid.
What other infections can this organism cause? |
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Definition
Allergic Bronchopulmonary Aspergilliosis: Invasive, non-dimorphic mold
1) Allergic Bronchopulmonary disease in CF and Asthma patients
2) Aspergillomas in lung cavities left by TB
3) Aflatoxin production leading to HCC
4) Invasive/disseminated disease in immunocompromised |
|
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Term
Patient taking chronic steroids for SLE presents with CNS abnormalities and MRI reveals "soap bubble" lesions in the brain.
Latex agglutination test detects polysaccharid capsular antigen and a culture on Sabouraud's agar stains + with india ink , with yeasts with wide capsular halos and unequal budding.
What infections are caused by this organism? |
|
Definition
Cryptococcus neoformans: HEavy, encapsulatesd yeast found in soil and pigeon droppings.
** Latex agglutination test is more specific than culture
1) Meningitis
2) Cryptococcosis
**Inhalation with hematogenous spread** |
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Term
Diabetic patient presents with dyspnea and signs of ketotic acidosis. They are complaining of headache, facial pain and difficulty with vision.
On PE, you notice a black necrotic eschar on their face and order a fungal analysis immediately.
What are you expecting to see? |
|
Definition
Mucormycosis is classic in DKA patients and those with Leukemia (Rhizopus is also common)
- Mold with irregular, broad, non-septate hyphae branching at wide angles
- Proliferate in blood vessels where there is excess glucose and ketone, and often penetrate the cribriform plate and enter the brain producing abscesses. |
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Term
An AIDS patient with CD count of 150 presents with dyspnea and wheezing.
A CXR comes back revealing what looks like a severe, bilateral, diffuse interstitial pneumonia.
You order a lung biopsy/lavage immediately.
What do you see and how do you treat? What could have been done to prevent this? |
|
Definition
Pneumocystis jiroveci- Disc-shaped yeast forms on methanamine silver stain of lung tissue.
Treat with TMP-SMX, pentamidine, dapsone
**Should have started prophylaxis when CD4 dropped below 200!** |
|
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Term
| Which opportunistic fungal infections are yeasts, molds and dimorphic, respectively? |
|
Definition
1) Yeasts
- Cryptococcus
- Pneumocystis jiroveci
2) Molds
- Mucormycosis/Rhizopus
- Aspergillus
3) Dimorphic
- Candida (pseudohyphae at 20 degrees and germ tubes at 37 degrees)
- Sporothrix schenckii (cigar shaped budding yeast) |
|
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Term
Gardner presents with a string of pustules and nodules along their axillary lymphatic distribution.
What happened? How do you treat? |
|
Definition
Local infection with Sporothrix schenkii
- Dimorphic, cigar-shaped budding yeast that lives on vegetation and was introduced with thorn (most likely)
- Itraconazole or Potassium iodide ("Plant a rose in the pot") |
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Term
What protozoa produce primarily GI infections? How do you diagnose and treat them? Presentations are described below
1) Bloating, flatulence, foul-smelling and fatty diarrhea in campers and hikers
2) Bloody diarrhea, reddish-bronw liver abscesses with RUQ pain
3) Severe diarrhea in AIDs and mild, watery diarrhea in rest |
|
Definition
1) Giardia lamblia- Cysts in water
- Diagnose with Trophozoites or cysts in stool
- Treat with Metronidazole
2) Entameoba histolytica- Cysts in water
- Serology, trophozoites (with RBCs in cytoplasm) or cysts (with multiple nuclei) in stool
- Metronidazole and Iodoquinol
3) Cryptosporidium- Cysts in water
- Diagnose on acid-fast stain
- Prevention (filtering city water supplies)
- Nitazoxinide |
|
|
Term
How do you treat each of the following?
1) Giardiasis
2) Entameoba histolytica
3) Cryptosporidium |
|
Definition
All are water-borne GI protozoan infections
1) Metronidazole
- Bloating and fatty diarrhea with Trophozoite or cysts in stool
2) Metronidazole and Iodoquinol
- Bloody diarrhea with liver abscesses
- Serology and/or trophozoites, or cysts (with multiple nuclei) in stool
3) Prevent with filtration and Nitazoxinide
- HIV diarrhea with cysts on acid-fast |
|
|
Term
What protozoa produce primarily CNS infections? How do you diagnose and treat them? Presentations are described below
1) Brain abscess in HIV (ring-enhancing lesion on CT/MRI)
2) Rapidly fatal meningoencephalitis in swimmer after swimming in fresh water lake
3) African sleeping sickness; enlarged lymph nodes, recurring fever, somnolence and coma |
|
Definition
1) Toxoplasma gondii: Cysts in meat or cat feces; crosses placenta (avoid cats!)
- Serology and brain biopsy to diagnose
- Treat with Sulfadiazine and Pyrimethamine
2) Naegleria fowleri: Freshwater and enter via cribriform plate
- Amoebas in spinal fluid
- Treat with Amphotericin (few survivors)
3) Trypanosoma brucei, T. anbiense, T rhodesiense
- Painful Tsetse fly bite with organism in blood smear
- Suramin for blood-borne disease or Melarsoprol for CNS penetration
(it SURe is nice to go to sleep; MELA tonin helps with sleep) |
|
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Term
| Why might a young child present with chorioretinitis, hydropcephalus and intracranial calcifications? |
|
Definition
Congenital Toxoplasma infection (travels over placenta)
- Serology and Biopsy for protozoa
- Treat with Sulfadiazine + Pyrimethamine |
|
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Term
| What infection do fresh-water swimmer get that is almost universally fatal? |
|
Definition
Naegleria fowleri (Protozoa) enters via cribriform plate and produces rapidly fatal Meningoencephalitis
- Diagnose with amoebas in spinal fluid
- Try Amphotericin B, but it probs won't work. |
|
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Term
| What are the treatments of choice for a patient who just returned from Africa and presents with enlarged lymph nodes, recurring fever and somnolence? |
|
Definition
Did they get bit by a Tsetse fly (painful)?
African Sleeping Sickness is diagnosed with blood smear and treated with Suramin (blood-borne disease) and Melarsoprol (CNS penetration).
T. brucei, gambiense, rhodesiense |
|
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Term
Which Protozoa produce hematological infections?
How do you diagnose/treat them? |
|
Definition
1) Plasmodium (Anopheles mosquitos)
- Blood smear for trophozoite ring forms and/or RBC schizont with merozoites
- Faciparum- Start with chloroquine (block heme polymerase) and add Mefloquine if needed
- Malariae- same as falciparum
- Vivax/ovale- Add Primaquine for dormant form in liver (hypnozoite)
2) Babesia- Ixodes tick like B. burdorferi
- Look for Maltese cross and ring form in smear
- Quinine, Clindamycin |
|
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Term
Which form of Plasmodium infection is described by each of the following?
1) 48-hr cycle (tertian; includes fever on first day and third day (48 h apart)). Lies dormant in liver as hypnozoite
2) Severe; irregular fever patterns with parasitized RBCs occluding capillaries in brain, kidneys and lungs
3) 72-hr cycle (quartan) or fever |
|
Definition
All transmitted by Anopheles mosquito, causing hematologic infection..
1) Vivax/Ovale
- Use Chloroquine (heme polymerase) and Mefloquine if resistant, just like other forms
- Add Primaquine for hypnozoites in liver
2) Falciparum
- Chloroquine +/- Mefloquine
3) Malariae
- Chloroquine +/- Mefloquine |
|
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Term
| What protozoan infection causes fever and hemolytic anemia in the northeastern US? Under what conditions might this infection be very dangerous? |
|
Definition
Babesia from Ixodes tick: most dangerous in Asplenia
1) Diagnose with blood smear, ring form and "maltese cross"
2) Treat with Quinine, Clindamycin |
|
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Term
Which protozoa can cause dilated cardiomyopathy, megacolon and megaesophagus, primarily in south america?
Diagnosis/treatment? |
|
Definition
Chaga's disease from Trypanosoma cruzi (Reduviid "kissing" bug) with painless bite (unlike Sleeping Sickness)
1) Diagnose with blood smear for trypanosoma
2) Nifurtimox treatment (vs. Suramin and Melarsoprol for Sleeping sickness) |
|
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Term
What protozoa are carried in sandflies and cause spiking fevers, pancytopenia and hepatosplenomegaly
Diagnosis/treatment? |
|
Definition
Leishmania donovani (think soldier's in desert)
1) Diagnose wtih macrophages containing "amastigotes"
2) Treat with Sodium stibogluconate |
|
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Term
Which protozoan STD causes an itching/burning vaginitis with foul-smelling greening discharge?
Diagnose/treat? |
|
Definition
Trichomonas vaginalis (NOT Gardnerella vaginalis, a gram-negative)
- transmitted sexually, and cannot exist outside body (no cyst forming ability)
1) Diagnose with Trophozoites (motile) on wet mount
2) Treat with Metronidazole for patient and partner (prophylaxis) |
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|
Term
Which intestinal nematode (roundworm) is described by each of the following and how would you treat it?
1) Anal pruritis caused by intestinal infection from food contaminated with nematode eggs.
2) Fecal/oral transmission causing intestinal infection with eggs visible in feces
3) Muscle inflammation and periorbital edema following consumption of undercooked pork
4) Vomiting, diarrhea and anemia with intestinal infection following soil penetration of skin
5) Intestinal infection with anemia (suck blood from intestinal walls) following stepping on a piece of glass and walking in the dirt. |
|
Definition
1) Enterobius vermicularis (pinworm)
- Bendazoles or Pyrantel pamoate (worms are BEENDy; treat with meBENDazole)
2) Ascaris lumbricoides (giant roundworm)
-Bendazoles or Pyrantel pamoate
3) Trichinella spiralis
-Bendazoles
4) Strongyloides stercoralis
- Bendazoles or ivermectin
5) Anclyostoma duodenale, Necator americanus (hookwork)
- Bendazoles or Pyrantel pamoate |
|
|
Term
Which tissue nematode (roundworm) is described in each of the following?
How would you treat?
1) Skin inflammation and ulceration from drinking water
2) Hyper-pigmented skin (nodules) and river blindness following female black fly bite, with possible allergic reaction to microfilaria
3) Swelling of skin (can see work crawling in conjunctiva) from fly (deer, horse, mango)
4) Blockage of lymphatic vessels (elephantiasis) 9 months-1 year following bite with female mosquito
5) Granulomas (blindness if in eye) and visceral larva migrans from food contamination with eggs |
|
Definition
1) Dracunculus medinensis
- Niridazole, prolonged extraction
2) Onchocerca volvulus *black vision, blackflies, black skin nodules)
- Ivermectin (IVERmectin for rIVER blindness)
3) Loa Loa
- Diethylcarbamazine
4) Wuchereria bancrofti
- Diethylcarbamazine
5) Toxocara canis
- Diethylcarbamazine |
|
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Term
Which Cestode (Tapeworm) is described in each of the following and how would you treat?
1) Larvae in undercooked pork leads to intestinal worms and egg ingestion causes cysticercosis and neurocysteicercosis, mass lesions in brain ("Swiss cheese" appearance)
2) Ingestion of larvae in raw freshwater fish causes vitamin B12 deficiency, resulting in macrocytic anemia
3) Eggs in dog feces can cause cysts in liver, causing anaphylaxis if echinococcal antigens are released from cysts (surgeons inject ethanol before removal to kill daughter cysts) |
|
Definition
1) Taenia solium
- Praziquentel (use -bendazoles for neurocysticercosis)
2) Diphyllobothrium latum
- Praziquantel
3) Echinococcus granulosus
- Bendazoles |
|
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Term
Which Trematode (fluke) is described in each of the following and how would you treat?
1) Snail hosts; cercariae penetrate skin of humans, causing granulomas, fibrosis and inflammation of spleen and liver. Chronic infection with certain strains carry risk of squamous cell bladder cancer.
2) Undercooked fish: causes inflammation of biliary tract, producing pigmented gallstones and associated with cholangiosarcoma
3) Undercooked crab meet, causing inflammation and secondary bacterial infection of the lung, causing hemoptysis. |
|
Definition
Hit the flukes with Praziquantel
1) Schistosoma
- Praziquantel
- S. haematobium are risk for bladder cancer
2) Clonorchis sinensis
- Praziquantel
3) Paragonimus westermani
- Praziquantel |
|
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Term
| Which nematodes are ingested and which ones enter via the skin? |
|
Definition
1) Ingested- You'll get sick if you EAT these
- Enterobius (pinworm), Ascaris (giant roundworm), Trichinella
2) Cutaneous- These get into your feet from the SANd
- Strongyloides, Ancylostoma, Necator (hookworm) |
|
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Term
Which parasites produce each of the following key findings?
1) Brain cysts, seizures
2) Liver cysts
3) B12 deficiency
4) Biliary tract disease, cholangiocarcinoma
5) Hemoptysis
6) Portal hypertension
7) Hematuria and bladder cancer
8) Perianal pruritis
9) Microcytic anemia |
|
Definition
1) Taenia solium (cysticercosis, Cestode)- uncooked pig
2) Echinococcus granulosus (Cestode/tapeworm)- dog feces
3) Diphyllobothrium latum (Cestode)- Raw freshwater fish
4) Clonorchis sinensis (Fluke)- Undercooked fish
5) Paragonimus westermani (Fluke)- Crab meet
6) Schistosoma mansoni (fluke)- Snails
7) Schistosoma haematobium (fluke)- Snails
8) Enterobius vermicularis (pinworm nematode)- Food
9) Anclystoma, Necator (hookworm nematode)- Skin on feet |
|
|
Term
Which parasites produce each of the following key findings?
1) Brain cysts, seizures
2) Liver cysts
3) B12 deficiency
4) Biliary tract disease, cholangiocarcinoma
5) Hemoptysis
6) Portal hypertension |
|
Definition
1) Taenia solium (cysticercosis, Cestode)- uncooked pig
2) Echinococcus granulosus (Cestode/tapeworm)- dog feces
3) Diphyllobothrium latum (Cestode)- Raw freshwater fish
4) Clonorchis sinensis (Fluke)- Undercooked fish
5) Paragonimus westermani (Fluke)- Crab meet
6) Schistosoma mansoni (fluke)- Snails |
|
|
Term
Which parasites produce each of the following key findings?
1) Brain cysts, seizures
2) Liver cysts
3) B12 deficiency
4) Biliary tract disease, cholangiocarcinoma
5) Hemoptysis
6) Portal hypertension
7) Hematuria and bladder cancer
8) Perianal pruritis
9) Microcytic anemia |
|
Definition
1) Taenia solium (cysticercosis, Cestode)- uncooked pig
2) Echinococcus granulosus (Cestode/tapeworm)- dog feces
3) Diphyllobothrium latum (Cestode)- Raw freshwater fish
4) Clonorchis sinensis (Fluke)- Undercooked fish
5) Paragonimus westermani (Fluke)- Crab meet
6) Schistosoma mansoni (fluke)- Snails
7) Schistosoma haematobium (fluke)- Snails
8) Enterobius vermicularis (pinworm nematode)- Food
9) Anclystoma, Necator (hookworm nematode)- Skin on feet |
|
|
Term
| Distinguish between "Typhoid fever" and "Typhus" |
|
Definition
1) Typhoid fever caused by Salmonella typhi bacteria
2) Typhus caused by Rickettsia prowazekii (epidemic) or R. typhus (endemic)
- Scrub typhus caused by Orientia tsutsugamushi |
|
|
Term
| What are the general structural features of viral particles? |
|
Definition
Can be naked icosahedral, enveloped icosahedral or enveloped helical
1) Naked icosahedral
- Nucleocapsid with a nuclei acid inside
2) Enveloped icosahedral
- Has a lipid bilayer and surface protein expression
3) Enveloped helical
- Similar to 2, but with a matrix or "core" protein as well underneath the lipid bilayer and outside of the nucleic acid and capsid protein. |
|
|
Term
| How can viruses exchange genetic information (4 ways)? |
|
Definition
Switch between chromosomes (1), between segmented genomes (2), fill in for one another (3) or coat one another (4)
1) Recombination
- Exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology
2) Reassortment
- Viruses with segmented genomes (influenza) exchange segments (high frequency recombination)
**cause of worldwide flu pandemics**
3) Complementation
- When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein, the non-mutated virus "complements" the mutated one by making a functional protein that serves both.
4) Phenotypic mixing
- Cell infected by 2 viruses at once. Genome of virus A partially or completely coated (forming pseudovirion) with the surface protein of virus B. Type B protein coat determines the infectivity of the phenotypically mixed virus (progeny will still have type A coat) |
|
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Term
| Why are live vaccines more potent that killed vaccines, and why are they also more dangerous? |
|
Definition
Live vaccines like MMR, smallpox, yellow fever, VZV, Sabin's polio and influenza induce BOTH cell-mediated and humoral immune responses, compared to killed vaccines, which only hit humoral (they don't need boosters!)
Live vaccines rarely revert to virulent forms (causes of smallpox in US) |
|
|
Term
| What are the live and killed viral vaccines available? |
|
Definition
1) Live
" See small yellow chickens get vaccinated with Sabin's and MMR!"
- Small pox
- Yellow fever
- VZV
- Polio (sabin)
- MMR
- Influenza (intranasal)
2) Killed
"RIP Always"
- Rabies, Influenza (injection), Polio (salk), HAV |
|
|
Term
| What recombinant vaccines are currently available? |
|
Definition
1) HBV (antigen= recombinant HBsAg)
2) HPV (types 6, 11, 16, 18) |
|
|
Term
| Which live attenuated vaccine is the only one that can be given to HIV patients? |
|
Definition
MMR (measles, mumps, rubella)
All others are contraindicated because of risk of viral conversion in immunocompromised host |
|
|
Term
Which vaccine should NOT be given to immunocompromised patients?
1) MMR
2) Salk Poliovirus
3) Smallpox vaccine
4) Rabies vaccine
5) Influenza injection |
|
Definition
3- Live attenuated
**ONLY live option is MMR here** |
|
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Term
What is the only DNA virus that is not a dsDNA?
Which is the only one that is not linear? |
|
Definition
1) Parvovirus is ssDNA
2) Papilloma, Polyoma and Hepandnaviruses are circular |
|
|
Term
What is the only RNA virus class that is not ssRNA
What are the positive-strandedd RNA viruses? |
|
Definition
1) Reovirus (Rotavirus and Coltivirus)
- "repeato-virus"
2) I went to a RETRO TOGA party, where I drank FLAVored CORONA and ate HIPPY CALIFORNIA PICKLES
- Retrovirus
- Togavirus (alpha and rubi)
- Flavivirus (hep C and flavivirus)
- Coronavirus
- Hepevirus
- Calicivirus (Norwalk and hep E)
- Picornavirus (enterovirus and rhinovirus) |
|
|
Term
| What is the major difference between a naked (+) strand ssRNA virus and a naked (-) strand ssRNA and dsRNA virus |
|
Definition
The (+) strand is essentially a functional mRNA, ready to be translated.
(-) strand viruses need to be transcribed to + strand before they are competent |
|
|
Term
| What is the only diploid virus class? |
|
Definition
Retroviruses have 2 identical ssRNA molecules and are diploid (HTLV-1,2 and HIV 1,2)
All others are haploid (1 copy of DNA or RNA) |
|
|
Term
| Where do DNA and RNA viruses replicate, respectively? |
|
Definition
1) DNA- Nucleus
- EXCEPTION is poxvirus
2) RNA- cytoplasm
- EXCEPTION is Influenza and retrovirus |
|
|
Term
| What are the naked viruses? How do viruses normally acquire envelopes? |
|
Definition
1) Naked CPR and PAPP smears
- RNA = CPR (Calici, Picorna, Reo)
- DNA= PAPP (Parvo, Adeno, Papilloma, Polyoma)
2) They usually acquire them as they exit the host cell membrane (taking it with them)
- EXCEPTION is herpesviruses, which acquire envelopes from nuclear membranes |
|
|
Term
| What are the DNA viruses and what are their general characteristics? |
|
Definition
1) HHAPPPPy viruses
(Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma)
2) double stranded (except Parvo)
3) linear (except Hepadna, Papilloma and Polyoma)
4) Icosahedral (except Pox/complex)
5) Replicate in the nucleus (except Pox, which carries own DNA-dependent RNA polymerase) |
|
|
Term
| What characteristics differentiate Pox viruses from other DNA viruses? |
|
Definition
| They are Complex, rather than Icosahedral and they DO NOT replicate in the nucleus (they carry their own DNA-dependent RNA polymerase for the cytoplasm). |
|
|
Term
| What are the major members of the Herpes virus family and their medical importance? |
|
Definition
Linear dsDNA virus with an envelope
1) HSV-1: Oral (and some) genital lesions
- Spontaneous temporal lobe encephalitis, Keratoconjunctivitis
2) HSV-2: Genital (and some oral) lesions
3) VZV (3): chicken pox, zoster
4) EBV (4): Mononucleosis, Burkitt's lymphoma, Hodgkin's
5) CMV (5): Infection in immunosuppressed patients (AIDS retinitis); congenital defects
6) HHV-6: Roseola (exanthem subitum)
7) HHV-7: Insignificant
8) HHV-8: Kaposi's sarcoma-associated (KSHV) |
|
|
Term
Which herpes virus is described by each of the following
1) Shingles
2) Roseola (exanthem subitum)
3) Genital (and some oral) lesions
4) Spontaneous temporal lobe encephalopathy and oral lesions
5) Kaposi's sarcoma
6) AIDS retinitis
7) Burkitt's lymphoma |
|
Definition
All are enveloped dsDNA viruses with linear structure
1) HHV 3- VZV
2) HHV 6
3) HSV-2
4) HSV-1
5) HHV-8 (KSHV)
6) HHV-5 (CMV)
7) HHV-4 (EBV) |
|
|
Term
What is the only non-retrovirus with a reverse transcriptase?
What clinical disease features are associated? |
|
Definition
Hepadna virus (HBV): enveloped dsDNA virus with partial circular structure
- Causes acute or chronic hepatitis
- Available toxoid vaccine (HBsAg) |
|
|
Term
Which DNA virus is described by each of the following?
1) Possesses reverse transcriptase and partial circular dsDNA genome
2) Cause of febrile pharyngitis, pink eye, pneumonia and acute hemorrhagic cystitis
3) Aplastic crisis in sick cell diseases and "slapped cheeks" in children
4) Genital warts or cervical cancer, depending upon serotype
5) Progressive multifocal leukoencephalopathy in HIV patients
6) BK virus that attacks kidneys of transplant patients
7) Molluscum contagiosum- flesh-colored dome lesions with central dimples |
|
Definition
1) Hepadna virus (HBV)- enveloped dsDNA virus that causes acute and chronic hepatitis (available toxoid vaccine against HBsAg)
2) Adenovirus: Non-enveloped dsDNA virus with linear genome
3) Parvovirus B19: Non-enveloped ssDNA virus with linear (-) genome (smallest DNA virus)
- slapped cheeks are in Erythema infectiosum or "fifth's disease"
4) Papillomavirus: Non-enveloped dsDNA virus with circular genome
- 1,2, 6 and 11 (warts) vs. 16 and 18 (cervical cancer)
5) Polyomavirus: Non-enveloped dsDNA virus with circular genome
- JC virus causes PML (Junky Cerebellum)
6) Also Polyomavirus, but BK virus affects kidney, instead of JC
7) Poxvirus: (largest) Enveloped dsDNA virus with complex geometry, linear genome and unique DNA-dependent RNA polymerase that allows it to replicate outside of nucleus |
|
|
Term
Which of the following is NOT associated with HHV-1
1) Sporadic temporal lobe encephalopathy
2) Gingivostomatitis
3) Keratoconjunctivitis
4) Latent infection in facial nerve ganglion
5) Herpes labialis |
|
Definition
4- Lies latent in trigeminal ganglia
Most common cause of sporadic encephalitis in US
More commonly causes oral lesions (compared to genital in HHV 2) |
|
|
Term
Which herpes viruses are spread in each of the following manners?
1) Respiratory secretions
2) Saliva
3) Sexual contact
4) Perinatally
5) Congenital
6) Transfusion/transplant |
|
Definition
1) HSV-1, HHV-3 (VZV), HSV-4 (EBV)
2) HSV-1, HHV-4 (EBV)
3) HSV-2, HHV-5 (CMV), HHV-8 (KSHV)
4) HSV-2
5) HHV-5 (CMV)
6) HHV-5 (CMV) |
|
|
Term
| Where do Herpesviruses lay dormant? |
|
Definition
1) CN V ganglia: HSV-1 and VZV (VZV can also lie in DRG)
2) Sacral ganglia: HSV-2
3) B cells: EBV
4) Mononuclear cells: CMV |
|
|
Term
Which herpes virus is responsible for each of the following and what else can it cause?
1) Congenital infections and "owl eye" inclusions
2) Spontaneous temporal lobe encephalopathy
3) Shingles and encephalitis
4) Roseola
5) Kaposis sarcoma in AIDs patients
6) Genital herpes
7) Nasopharyngeal carcinoma |
|
Definition
1) CMV/HHV-5
- Mononucleosis (negative monospot), pneumonia, retinitis
- dormant in mononuclear cells
2) HSV-1
- Keratoconjunctivitis, Gingivostomatitis, Herpes labialis
- lies dormant in CN V ganglia)
3) VZV (HHV-3)
- Pneumonia
- Lies in DRG or CNV ganglia
4) HHV-6 (exanthum subitum)
- Rash preceded by high fevers for several days that can cause seizures
5) HHV-8 (KSHV)
6) HSV-2
- Neonatal herpes
- Latent in sacral ganglia
7) HHV-4 (EBV)
- Mononucleosis and Burkitt's lymphoma
- latent in B cells |
|
|
Term
| What test allows HSV identification? |
|
Definition
Tzanck test- smear of an opened skin vesicle to detect multi-nucleated giant cells
- will hit HSV-1, HSV-2 and VZV
- Infected cells have intra-nuclear Cowdry A inclusions |
|
|
Term
Which of the following is NOT known to be caused by HHV-4
1) Hepatosplenomegaly
2) Atypical, reactive B cells on smear
3) Pharyngitis
4) Lymphadenopathy of posterior cervical chain
5) Present in 15-20 year olds
6) Associated with Hodgkins and endemic Burkitt's lymphomas |
|
Definition
HHV-4= EBV
2) In mononucleosis, the atypical cells are cytotoxic T cells responding to infected B cells and "hugging" RBCs.
Lymphadenopathy (posterior cervical), Pharyngitis and Hepatosplenomegaly is classic presentation in 15-20 year old.
EBV is associated with both Hodgkins and Burkitt's (endemic) lymphomas, as well as nasopharyngeal carcinoma |
|
|
Term
| What is a "Monospot" test? |
|
Definition
Tests for EBV, the "kissing disease"
Looks for heterophyle antibodies detected by agglutination of sheep or horse RBCs.
Recall, latent in B cells and causes abnormal, reactive T cells in smear. |
|
|
Term
| What are the enveloped RNA viruses? Which ones are naked? |
|
Definition
1) Enveloped
ICOSAHEDRAL
- Togavirus (ssRNA +): Alpha and Rubivirus
- Flavivirus (ssRNA +) : Hep C, west nile, yellow, dengue
- Retrovirus (ssRNA + diploid): HTLV-1, HIV
- Deltavirus (ssRNA - circular): HDV
HELICAL
- Coronavirus (ssRNA+)
- Bunyavirua (ssRNA -): CEV, Hantavirus
- Arenavirus (ssRNA -): Lassa fever
- Orthomixovirus (ssRNA -): Influenza
- Paramixovirus (ssRNA -): Parainfluenza, Pneumovirus, Rubula, Morbiliform
- Rhabdovirus (ssRNA -): Rabies
- Filovirus (ssRNA -): Ebola, Marburg
2) Non-enveloped
- Picornavirus
- Calicivirus
- Reovirus |
|
|
Term
| Which viruses are Arboviruses? |
|
Definition
Mosquitos and/or Ticks
1) Bunyavirus: Enveloped circular ssRNA (-) virus with segmented, helical structure
- California encephalitis
- Sandfly/Rift Valley fevers (3 day fever/sandfly/ Phlebovirus- mosquito)
- Crimean-Congo hemorrhagic fever (Hantavirus)
2) Togavirus: enveloped ssRNA (+) non-segmented virus with linear and icosahedral geometry
- Alphavirus (Eastern and Western Equine encephalitis)
- Rubella is NOT an arbovirus
3) Flavivirus: enveloped ssRNA (+) non-segmented virus with linear and icosahedral geometry
- Yellow fever, West Nile, Dengue and St. louis encephalitis
- HCV is NOT an arbovirus
4) Reovirus: non-enveloped DS segmented virus with icosahedral geometry
- Coltivirus causes colardo tick fever
- Rotavirus is NOT an arbovirus |
|
|
Term
| Which are the negative stranded RNA viruses? |
|
Definition
These viruses bring their own RNA-dependent RNA polymerases (similar to how Pox virus brings a DNA-dendepent DNA polymerase).
Always Bring Polymerase Or Fail Replication
- Arenaviruses (segmented)
- Bunyaviruses (segmented)
- Paramixoviruses (non-segmented)
- Orthomixovirus (segmented)
- Filovirus (non-segmented)
- Rhabdovirus (non-segmented) |
|
|
Term
Which of the following DOES NOT have its own RNA-dependent RNA polymerase?
1) Rhabodovirus
2) Arenavirus
3) Coronavirus
3) Bunyavirus
4) Paramixovirus
5) Orthomixovirus
6) Filovirus |
|
Definition
All of these are helical RNA viruses
3- Coronavirus is a ssRNA (+) virus, which does not need to be transcribed to (+) strain before replication.
All others are (-) strand viruses:
Always (Arena)
Bring (Bunya)
Polyermase (Paramixo)
Or (Orthomixo)
Fail (Filovirus)
Replication (Rhabdo) |
|
|
Term
| Which RNA viruses are segmented and what does this feature afford them? |
|
Definition
Segmented genomes can undergo reassortment, which is responsible for pandemic spreads.
BOAR
Bunyavirus, Orthomixovirus, Arenavirus, Reovirus (DS circular)
**Bunya, Orthomixo and Arena are also (-) strand and carry an RNA-dependent RNA Poli** |
|
|
Term
Which small RNA virus class is known to cause aseptic meningitis?
What are the major members? |
|
Definition
Picornavirus: ssRNA (+) non-segmented virus with icosahedral structure.
- One large polypeptide is cleaved into functional viral proteins
PERCH on a "peak" (pico)
- Polio, Echovirus, Rhinovirus, Cocksackie , HAV
- All are enteroviruses EXCEPT rhino (common cold)
- All cause meningitis, except rhino and HAV |
|
|
Term
| What diseases do each of the Picornaviruses cause? |
|
Definition
Icosahedral, non-enveloped, ssRNA (+), non-segmented
PERCH on a "peak" (pico)
1) Polio: Paralytic poliomyelitis (Salk and Sabin vaccines)
2) Echovirus: most common cause of aseptic meningitis
- febrile illness in children
3) Rhinovirus: Common cold with >100 serotypes, acid labile (destroyed in stomach)
4) Cocksackie: Herpangina (A), Myocarditis and pericarditis (B) ,URI and aseptic meningitis (A or B)
5) HAV: Acute viral hepatitis from fecal:oral |
|
|
Term
Patient presents with high fever, black vomitus and jaundice.
What kind of virus is causing these symptoms? |
|
Definition
Yellow Fever: Aedes mosquitos with monkey or human reservoir
Live vaccine available.
Flavivirus: icosahedral..enveloped...ssRNA (+), non-segmented virus |
|
|
Term
What is the most common cause of infantile gastroenteritis and acute diarrhea in the winter time?
Classic presentation is "kindergarten ll gets stomach bug" |
|
Definition
Rotavirus: Icosahedral...non-enveloped...DS segmented RNA virus
ROTA- right out the anus
**Villous destruction with atrophy leads to poor Na+/water reabsorption and can cause hypovolemia** |
|
|
Term
| How do Orthomixoviruses exchange genetic information? |
|
Definition
Orthomixovirus is an enveloped ssRNA (-) virus with a segmented genome (one of the BOAR segmented RNA viruses).
8 segments contain HG (viral entry) and NA (viral exit) antigens, and patients with the flue are at risk for bacterial super-infections.
1) Genetic shift- Reassortment with high-frequency recombination between viruses (Swine Flu)
2) Genetic drift- Random mutations in a single viral genome |
|
|
Term
| What is the most dangerous complication of most orthomixovirus infections and how are they prevented? |
|
Definition
1) Bacterial superinfection
2) Killed viral vaccine (re-formaulated each year)
- Nasal live is available as well |
|
|
Term
Child presents with fever, post-auricular adenopathy, lymphadenopathy, arthralgias and a fine truncal rash that began at their head 1 days earlier and then traveled to their trunk. It goes away 1 day later.
What is going on? |
|
Definition
Migrating rash is characteristic of German, 3-day measles from Rubella virus.
** Mild in children but serious congenital disease (TORCH infection)**
Togavirus: enveloped, ssRNA (+) virus with non-segmented genome. |
|
|
Term
| What are the Paramixoviruses and what diseases do they cause? |
|
Definition
Enveloped ssRNA (-) viruses with non-segmented genomes
Contains F protein, which causes respiratory epithelial cell fusion and mutli-nucleated cell formation (give Palivizumab to prevent infantile pneumonia in premature)
Disease in children
1) Parainfluenza: croup-seal barking cough
2) Pneumovirus (RSV): Bronchiolitis/pneumonia in infants
3) Rubulavirus (Mumps): Parotitis, Orchitis, Meningitis
4) Morbillivirus (Measles, Rubeola)
- Cough, Coryza, Conjunctivitis
**Koplick spots (red with blue/white center in mouth) precede rash** |
|
|
Term
| How can you prevent viral pneumonia in premature infants? |
|
Definition
Palivizumab: anti-F protein against RSV/pneumovirus (version of Paramixovirus)
F-protein causes respiratory epithelial cell fusion and multi-nucleated cell formation with pneumonia and bronchiolitis |
|
|
Term
| How does the rash in Measles (Rubeola) differ from that of Rubella? |
|
Definition
Measles (Paramixovirus.. Morbillivirus) has Koplik spots in buccal mucosa (red with blue/white center) that are followed by rash that spreads from head to toe, including the hands and feet (DO NOT confuse with Roseola, which is HHV-6)
Rubella (Togavirus: Rubivirus) rash is a descending truncal rash. |
|
|
Term
| Why might you be worried if a child presents with red spots in his buccal mucosa that have white/blue centers, as well as a descending maculopapular rash beginning on his hands and feet? |
|
Definition
Rash and Koplik spots= Measles (Morbilivirus of Paramixovirus family)
3 C's= Cough, Coryza (upper cold), Conjunctivitis
Measles/Rubeola can later cause SSPE (sever, subacute, panencephalitis- 1:2000) and giant cell pneumonia (immunocompromised) |
|
|
Term
Child presents with a swollen neck and large, tender testis.
What vaccine might he have missed and why are you worried? |
|
Definition
Mumps makes your parotid and testes as big as POM-poms
The last feature of Mumps (MMR vaccine), is aseptic meningitis and sterility after puberty is a common concern
Mumps is a Rubivirus of the paramixovirus family, a group of viruses that are enveloped, ssRNA (-) viruses with non-segmented genomes and helical geometry. |
|
|
Term
What virus has a "bullet-shaped" capsid and causes negri body inclusions in nerve cell cyptoplasm (commonly cerebellar)?
What disease does it cause? |
|
Definition
Rhabdovirus: enveloped, ssRNA (-) virus with non-segmented genome
Rabies has long incubation period (weeks to months) during which time is spreads retrogradely on CNS neurons (GIVE PROPHYLACTIC KILLED VACCINE when bite occurs)
1) Begins with Fever/malaise
2) Agitation and photophobia/hydrophobia
3) Finally, paralysis, coma and death. |
|
|
Term
| What are the modes of transmission of the different Hepatitis viruses? |
|
Definition
1) HAV: fecal-oral
- non-enveloped, ssRNA (+), non-segmented Picornavirus
2) HBV: Parenteral, sexual, maternal-fetal
- DNA hepadnavirus with partial circular ds genome
- uses cellular RNA polymerase to make RNA and personal RT to make DNA and then DNA-dependent DNA polymerase to replicate
3) HCV: IV drug use, blood, post-transfusion
- enveloped ssRNA (+) non-segmented Flavivirus
4) HDV: Parenteral, sexual, maternal fetal
- enveloped ssRNA (-) virus with circular genome that is superinfection or co-infection with HBV
5) HEV: Fecal-oral (waterborne usually)
- non-enveloped ssRNA (+) non-segmented virus in Calivirus family |
|
|
Term
Which hepatitis viruses have "carrier states"?
What long-term risks do these viruses carry? |
|
Definition
HBV, HCV, HDV all have HCC risk
HBV (act as oncogene)
HCV (chronic inflammation with cirrhosis)
HDV (defective virus that needs HbsAg as envelope) |
|
|
Term
| Which hepatitis viruses survive in the gut and what are the most important complications? |
|
Definition
Vowels hit you Bowels: fecal-oral transmitted, naked viruses that do not rely on envelope (not destroyed by stomach acid)
1) HAV: Asymptomatic, Acute and Alone (no carriers)
- short incubation and acute presentation
2) HEV: Enteric, Expectant mothers, Epidemic (water-borne)
- High mortality in pregnant mothers! |
|
|
Term
|
Definition
DNA virus with partial circular DNA genome
Sexual transmission with acute and chronic disease, and HCC risk.
1) uses cellular RNA polymerase to make RNA
2) uses reverse transcriptase to make DNA
3) uses DNA-dependent DNA polymerase to replicate. |
|
|
Term
What do each of the following tests indicate when positive?
1) Anti-HAVAb (IgM)
2) Anti-HAVAB (IgG)
3) HBsAg
4) Anti-HBsAg
5) HBcAg
6) Anti-HBcAg
7) HBeAg
8) Anti-HBeAg |
|
Definition
1) Acute, active HAV infection
2) Prior HAV infection or prior vaccination (both protective)
3) HBV infection (surface)
4) Immunity to HBV
5) core antigen
6) IgM= acute/recent infeciton, IgG= chronic disease (positive during Window period)
7) Active viral replication and high Transmissibility
8) Low transmissability |
|
|
Term
What period of HBV infection do each of the following test results indicate?
1) HBsAg +, HBeAg +, Anti-HBeAb -, Anti-HBcAb (IgM)
2) Anti-HBeAb + ONLY
3) Anti-HBsAb +, Anti-HBeAb -, Anti-HBcAB -, HBsAg -
4) HBsAg +, Anti-HBsAb -, Anti-HBcAb +, HBeAg -
5) Anti-HBsAb +, Anti-HBeAb +, Anti-HBcAB +, HBsAg - |
|
Definition
1) Acute HBV infection (1-3 months)
- Antigens of surface protein is present, but no antibody is
- Acute antibody against core protein is present, playing to recency of infection (HBeAg indicates infectivity)
2) Window period (5-8 months post)
- Transmissibility is low
3) Immunized
- If this was a recovery, you would see Anti-HbeAg and Anti-HBcAb IgG
4) Chronic HBV with LOW infectivity, since HBeAg is not positive
- HBeAg determines infectivity
5) Recovery |
|
|
Term
| What is the order of antigen/antibody appearance in HBV infection? |
|
Definition
1) HbsAg (1 month)- Incubation
2) HBeAg (1-2 months)
3) Anti-HBc (2 months- IgM then IgG)
- Acute/prodrome begins when HBcAb IgM appears
- When IgG appears, it is early-late disease (late when anti-HBs appears)
4) Anti-HBeAb (5-8 months- window period)
5) Anti-HBsAb (6 months) |
|
|
Term
| Describe the basic structure of a HBV viral particle. |
|
Definition
42 nm Hepadna virus (DNA virus with partial circular genome)
1) Coat protein (HBsAg)
2) Core protein (HBcAg)
3) DNA genome with DNA-dependent polymerase and Reverse transcriptase |
|
|
Term
| Describe the basic structure of the HIV virus. |
|
Definition
Enveloped Lentivirus with a Diploid genome
- outer lipid membrane with protruding glycoproteins (gp120 and gp41)
- inner matrix
- nucleus with capsid, RNA genome and RNA RT
3 Structural genes
1) Env (acquired through budding from host membrane)
-gp120 (T-cell attachment): docking glycoprotein
-gp41 (fusion and entry): transmembrane glycoprotein
2) Gag (gp24)
- Capsid protein that surrounds RNA and RT in nucleus
3) pol (RT): found in nucleus
- Synthesize dsDNA from RNA and integrates into host genome
**matrix proteins include p17** |
|
|
Term
| How does HIV infect host T cells? |
|
Definition
1) gp120 binds to CXCR4 or CCR5 co-receptor on CD4+ T cells and enters cell via gp41-medaited fusion
**binds CCR5 and CD4 on macrophages as well, and homozygous CCR mutations cause immunity (heterozygous has slower course)
2) HIV integrase allow virus to enter nucleus and replicate with RT to dsDNA, which integrates into the host genome,
3) HIV protease cleaves newly synthesized polypeptides to infective forms |
|
|
Term
| How do you screen and confirm an HIV diagnosis? How about AIDS? |
|
Definition
1) Screen with ELISA (sensitive)
- High false positive rate (RULE OUT)
2) Confirm with Western (specific)
- High false negative rate (RULE IN)
- can monitor effects of drug therapy on viral load with HIV PCR/viral load tests.
3) AIDS diagnosis
- AIDS <= 200 CD4+ (normal 500-1500), HIV positive with Pneumocystis pneumonia (indicator condition), or CD4:CD8 ratio of < 1.5 |
|
|
Term
| Under what conditions are ELISA/Western blot tests for HIV falsely negative or positive? |
|
Definition
Detect antibodies against viral proteins
1) False negatives in first 1-2 months of infection
2) False positive in babies borne to infected mothers (anti-gp120 crosses placenta) |
|
|
Term
| What are the 4 stages of an HIV infection? |
|
Definition
1) Flulike (acute)
- after 1 month and lasting about a month
- Initial dissemination and organ seeding
- CD4 drops to about 500 and HIV RNA spikes to 1100
2) Feeling fine (latent)
- 2 months-8 years
- CD4 count raises slightly to 700 for a month or 2, and then drops off
- HIV RNA drops off to 300
3) Falling count
- As CD4 drops below 400, you see constitutional symptoms and then begin to see opportunistic infections
- HIV RNA spikes again
4) Final crisis |
|
|
Term
As the CD4 count in HIV drops, there are a number of important risks that arise.
What are the basic categories of these complications? |
|
Definition
1) Reactivation of past infections
- TB, HSV, shingles
2) Dissemination of bacterial infections and fungal infections (Coccidio)
3) Non-hodkin's lymphoma |
|
|
Term
What pathogen is responsible for the following in an HIV (+) patient?
"Low-grade fevers, cough, hepatosplenomegaly and tongue ulcers."
CD4 <100, with oval yeast cells hiding in macrophages. |
|
Definition
| Histoplasma capsulatum (only causes pulmonary symptoms in immunocompitent) |
|
|
Term
What pathogen is responsible for the following in an HIV (+) patient?
" Fluffy white cottage-cheese lesions"
Pseudohyphae and found in oral cavity if CD4< 400 and in esophagus in CD4 <100 |
|
Definition
Thrush from Candida. albicans.
Dimorphic fungus |
|
|
Term
What pathogen is responsible for the following in an HIV (+) patient?
" Superficial vascular proliferation with tumor-like masses in skin, with PMN infiltration on biopsy" |
|
Definition
| Bartonella henselae (bacillary angiomatosis) |
|
|
Term
What pathogen is responsible for the following in an HIV (+) patient?
"Chronic watery diarrhea" with acid-fast yeasts seen in stool when CD4 <200 |
|
Definition
|
|
Term
What pathogen is responsible for each of the following in an HIV (+) patient?
1) Encephalopathy due to demylination when CD4 <200
2) Cerebral abscesses with ring-enhancing lesions on MRI (CD4 < 100)
3) India ink positive yeast in meningitis with narrow-based budding and large capsule (CD4 < 50)
4) Cotton-wool spots on fundoscopic exam, often presenting with esophagitis (CD <50)
5) Dementia |
|
Definition
1) Reactivation of latent JC virus (PML)
2) Toxoplasma gondii
3) Cryptococcus neoformans (may also cause encephalitis)
4) CMV
5) HIV proper |
|
|
Term
What pathogen is responsible for the following in an HIV (+) patient?
"Superficial neoplastic vascular proliferation with lymphocytic infiltration on biopsy" |
|
Definition
HHV-8 (Kaposi's sarcoma)
NOT B. henselae, which has NEUTROphillic infiltrate |
|
|
Term
What pathogen is responsible for each of the following in an HIV (+) patient?
1) Hairy leukoplakia on lateral tongue
2) NHL (large cell), often in oropharynx (Waldeyer's ring)
3) Squamous cell carcinoma of the anus (MSM) or cervix
4) Primary CNS lymphoma with focal or multiple lesions |
|
Definition
1) EBV
2) EBV (maybe)
3) HPV
4) EBV- differentiate from toxo |
|
|
Term
What pathogen is responsible for each of the following in an HIV (+) patient?
1) Interstitial pneumonia with "owl eye" inclusion bodies in cells on biopsy
2) Pleuritic pain, hemoptysis and pulmonary infiltrates on imaging
3) Pneumonia when CD4< 200
4) Fever, night sweats, weight loss and hemoptysis when CD4 <50 |
|
Definition
1) CMV interstitial pneumonia
2) Invasive aspergilliosis
3) Pneumocystis jiroveci
4) MAC (TB-like) |
|
|
Term
Which reactivation/opportunistic infections appear in an HIV (+) patient at each of the following CD4+ counts?
1) <400
2) <200
3) <100
4) <50 |
|
Definition
1) <400
- Oral thrush (Candida)
2) <200
- Chronic diarrhea (Cryptosporidium)
- PML (JC virus)
- PCP (Pneumocystis)
3) <100
- Esophageal thrush (candida)
- Fever/cough/tongue ulcer (Histoplasma)
- Cerebral abscesses (Toxoplasma gondii)
4) <50
- Meningitis (Cryptococcus- may also cause encephalitis)
- Retinitis with Cotton-wool spots in eye and esophagus (CMV)
- TB-like symptoms (MAC) |
|
|
Term
| What are the major sporadic, acquired and inherited Prion diseases? |
|
Definition
Caused by conversion of normal protein called prion protein (PrPc) to a beta-pleated form (PrPsc), which resists degradation and facilitates conversion of additional PrPc to PrPsc.
Accumulation results in spongioform encepthalopathy, dementia, ataxia and death.
1) Inherited: Gerstmann-Straussler-Scheinker syndrome
2) Acquired: Kuru (mad cow)
3) Sporadic: Creutzfeldt-Jakob disease (rapidly progressie dementia) |
|
|
Term
Which bacteria dominate as the normal flora in each of the following locations?
1) Skin
2) Nose
3) Oropharynx
4) Dental plaque
5) Colon
6) Vagina |
|
Definition
Neonates by C-seciton have no flora, but are colonized rapidly!
1) Staph epidermidis
2) S epidermidis; colonized by S. aureus
3) Viridans strep (Optochin resistant)
4) Strep mutans
5) Bacteroides >E. coli
6) Lactobacillus, colonized by E. coli and group B strep. |
|
|
Term
Which bugs cause food poisoning in the following contexts?
1) Seafood
2) Re-heated rice
3) Meats, mayonnaise, custard
4) Reheated meats
5) Canned foods (bulging)
6) Poultry, meet and eggs
7) Under-cooked meat |
|
Definition
1) Vibrio parahaemolyticus and V. vulnifucus (also wound infections from water contact)
2) Bacillus cereus ((start and end quick)
3) S. aureus (start and end quick)
4) C. perfringens
5) C. botulinum
6) Salmonella
7) E. coli O157:H7 |
|
|
Term
| Which bugs can mimic symptoms of appendicitis (Mesenteric adenitis with fever at RLQ pain)? |
|
Definition
- Y. enterocolitica (most common)
- C jejuni
- Non-typhoid Salmonella |
|
|
Term
| Which bugs cause bloody diarrhea? |
|
Definition
1) C. jejuni (comma shaped growth at 42)
2) Salmonella (Lactose negative; flagellar)
3) Shigella (Lactose negative; low ID50)
4) EHEC (O157:H7)
5) EIEC (Invades colonic mucosa)
6) Y. enterocolitica (Day-care outbreaks, pseudoappendicitis)
7) Entameoba histolytica (Protozoan) |
|
|
Term
Which of the following does NOT cause bloody diarrhea?
1) Entamoeba histolytica
2) ETEC
3) Salmonella
4) Shigella
5) C. jejuni
6) Y. enterocolitica |
|
Definition
2- Traveler's diarrhea with ST (GC/cGMP) and LT (AC/cAMP)
EIEC and EHEC will cause bloody diarrhea, as will the others listed here |
|
|
Term
| Which organisms are known to cause watery diarrhea? |
|
Definition
1) ETEC (traveler's diarrhea with ST and LT)
2) V. cholerae (Comma-shaped, rice-water)
3) C. dificile (Pseudomembranous colitis)
4) C. perfringens (Gas gangrene)
5) Giardia and Cryptosporidium (in HIV)
6) Viruses (Rota, Adeno, Noro) |
|
|
Term
Which organism would NOT produce a watery diarrhea?
1) Norovirus
2) C. perfringens
3) V. cholerae
4) Y. enterocolitica
5) Cryptosporidium
6) C. dificile |
|
Definition
| 4- Causes day-care outbreaks and pseudoappendicitis with bloody diarrhea |
|
|
Term
| Which viruses commonly cause watery diarrhea? |
|
Definition
1) Rotavirus (DS segemented RNA)
2) Adenovirus (DNA)
3) Norovirus (Calici RNA) |
|
|
Term
What are the most common causes of pneumonia in the following age groups?
1) Neonates (<4 weeks)
2) Children (4 w- 18 years)
3) Adults (18-40)
4) Adults (40-65)
5) Elderly |
|
Definition
1) Neonates
- Group B strep (agalactiae)
- Legionella
- Chlamydia trachomatas (most common!)
2) 4w- 18 y: Runts May Cough Sputum
- RSV
- Mycoplasma
- Chlamydia pneumonia (most common)
- Strep pneumo
3) Adults 40-65
- S. pneumonia
- H. influenzae
- Anaerobes
- Viruses
- Mycoplasma
4) Elderly
- S. pneumoniae
- Influenza
- Anaerobes
- H. influenzae
- Gram-negative rods |
|
|
Term
Which bugs cause Pneumonia in the following cases?
1) Nosocomial
2) Immunocompromised
3) Aspiration
4) Alcoholic/IV drug user
5) CF
6) Post-viral
7) Atypical |
|
Definition
1) Staph, enteric gram-negative rods
2) Staph, enteric gram-negative rods, fungi, viruses, PCP (HIV)
3) Anaerobes
4) S. pneumonia, Klebsiella, Staph
5) Pseudomonas
6) Staph, H. influenzae
7) Mycoplasma, Legionella, Chlamydia |
|
|
Term
What are the most common causes of Meningitis in the following age groups?
1) Newborn (0-6 months)
2) Children (6 month- 6 years)
3) 6-60
4) >60 |
|
Definition
N. meningididis is most common from 1 month to 18 years (petichia will be specific)
1) Newborn
- Group B Strep (agalactiae)
- E. coli
- Listeria
2) Child
- Strep. pneumo
- N. meningitidis
- H. influenza type B (vaccine)
- Enterovirus
3) 6-60
- S. pneumoniae
- N meningiditis
- Entervirus
- HSV
4) >60
- S. pneumoniae
- Gram negative rods
- Listeria |
|
|
Term
What viruses can cause meningitis?
What are the causes of meningitis in HIV? |
|
Definition
1) Enterovirus (cocksackie), HSV-2 (HSV-1 = encephalopathy), HIV, WNV, VZV
2) Cryptococcus, CMV, Toxoplasmosis, JC virus |
|
|
Term
| Why do children most commonly get haemophilus influenza B meningitis? |
|
Definition
|
|
Term
| How do you treat a suspected Listeria meningitis empirically? |
|
Definition
Cerftriaxone + Vancomycin + Ampicillin
For ALL meningitis, use Ceftriaxone and Vancomycin |
|
|
Term
| What are the CSF findings in Bacterial, fungal/TB and viral meningitis forms, respectively? |
|
Definition
Normal sugar= viral
PMNs= bacterial
Lymphocytes with low sugar= Fungal/TB
1) Bacterial
- Increased Pressure, PMNs, Protein and low Glucose
2) Fungal/TB
- Increased Pressure, Lymphocytes, Protein and low Glucose
3) Normal/increased pressure, increased lymphocytes, normal/increased protein and NORMAL sugar |
|
|
Term
What is the most common cause of Osteomyelitis in the following populations?
1) Most people
2) Sexually active
3) Diabetics and IV drug users
4) Sickle cell
5) Prosthetic replacement
6) Vertebral
7) Cat and dog bites or scratches |
|
Definition
Look for elevated CRP and ESR usually in kids
1) S. aureus
2) N. gonorrhoeae (rare), septic arthritis more common
3) Pseudomonas aeruginosa
4) Salmonella
5) S. aureus and S. epidermidis
6) TB (Pott's disease)
7) Pasteurella multicoda (gram negative oxidase + catalase +) |
|
|
Term
Patient presents with dysuria, frequency, urgency and suprapubic pain.
There are WBCs in her urine, but no casts.
There is a positive leukocyte esterase test and nitrite test.
What is going on?
What are the common predisposing factors in women? |
|
Definition
Symptoms of UTI (no casts, so not pyelonephritis). Positive LET means it is bacterial and Nitrite test means it is gram negative.
Most likely an E. coli UTI
- Women get it >>> men because short urethra
- Obstruction, kidney surgery, catheterization, GU malformation, diabetes and pregnancy are all risk factors. |
|
|
Term
How do men get UTIs?
What about the elderly males?
Congenital? |
|
Definition
1) Males and Infants with congenital defects typically have abnormal Vesicourethral reflux
2) Elderly have enlarged prostates.
**Others are typically ascending infections from urethra to bladder** |
|
|
Term
| What are the typical symptoms of Pyelonephritis and how do they differ from a UTI? |
|
Definition
1) Pyelonephritis
- Fever, chills, flank pain, CVA tenderness, hematuria and WBC casts
2) UTI
- Dysuria, urgency, frequency, suprapubic pain and WBCs (no casts) |
|
|
Term
What bugs might be causing a UTI under the following conditions?
1) Positive leukocyte esterase and Urease tests
2) Positive leukocyte esterase and Nitrite tests
3) Positive leukocyte esterase test only |
|
Definition
LET= bacterial, Nitrite= gram negative, Urease= urea splitters
1)
- Proteus Mirabilis ("swarming" mobility on agar and associated with struvite stones)
- Klebsiella (Mucoid capsule and viscious colones- 3rd leading cause!)
2)
- E. coli (leading cause with green metallic colonies on EMB agar)
- Serratia (nosocomial and drug-resistant with red pigments)
- Pseudomonas (Blue-green with fruity odor- nosocomial and drug-resistant)
3)
- Staph saprophyticus (2nd leading cause- found in sexually active women)
- Enterococcus (Nosocomial and drug-resistant) |
|
|
Term
| What are the common nosocomial UTIs that are drug-resistant? |
|
Definition
1) Pseudomonas (blue-green and fruity)
2) Enterobacter cloacae
3) Serattia marcescens (red) |
|
|
Term
| What are the top 3 leading causes of UTI? |
|
Definition
1) E. coli (lactose fermenting gram negative)
2) Staph saprophyticus (catalase positive, coagulase negative gram positive that is novobiocin resistant)
3) Klebsiella pneumoniae (lactose-fermenting gram negative) |
|
|
Term
| Which microbes pass from mother to fetus? |
|
Definition
ToRCHeS: hepatosplenomegaly, jaundice, TP and growth retardation.
**most transplacental or delivery (HSV-2)**
1) Toxoplasma gondii: cat feces or undercooked meat
- Mom asymptomatic
- Neonate Triad: Chorioretinitis, Hydrocephalus and Intracranial calcification
2) Rubella: respiratory droplets
- Mom has rash, lymphadenopathy and arhtritis
- Neonate Triad: PDA (or pulmonary artery hypoplasia), Cataracts and Deafness +/- "blueberry muffin" rash
3) CMV: sex or transplant
- Mom is asymptomatic or mono-like
- Kid has hearing loss, seizures, petechial rash, "blueberry muffin" rash
4) HIV: Sex
- Mom has variable presentation (CD4 level)
- Kid has recurrent infections and chronic diarrhea
5) HSV: Skin or mucous membrane contact
- Mom is asymptomatic
- Kid: Temporal encephalitis (HSV-1), Herpetic (vesicular) lesions
6) Syphilis: Sex
- Mom has chancre (primary), disseminated rash (secondary) or cardiac/neurological (tertiary)
- Kid may be stillbirth (hydropis fetalis), and will otherwise have facial abnormalities, saber shins and CN VIII deafness |
|
|
Term
Which microbe was passed from mom to kid in each of the following scenarios?
1) Mom had recent kidney transplant and is now asymptomatic, but baby presents with hearing loss, seizures, petechial rash and rash that looks like a blueberry muffin.
2) Mom is asymptomatic but kid has temporal encephalitis and vesicular lesions.
3) Mom has cardiac abnormalities and kid has saddle nose with hemorrhagic rhinitis, notched teeth and central deafness
4) Mom is sexually active and recovering from Pneumocystis pneumonia. Kid has recurrent infections and chronic diarrhea
5) Mom and kid at uncooked meat and have a cat, and while mom is asymptomatic, kid has chorioretinitis, hydrocephalus and intracranial calcifications
6) Mom has rash, lymphadenopathy and a rash while kid has PDA, cataracts and deafness |
|
Definition
ToRCHeS
Toxo, Rubella, CMV, HIV, HSV, Syphilis1) CMV
2) HSV-1
3) Syphillis (mom has tertiary syphilis)
4) HIV
5) Triad of Toxo
6) Triad of Rubella |
|
|
Term
Kids have many red rashes while growing up. What bug causes each presentation?
1) Rash beginning at head and moving down to trunk, with post-auricular lymphadenopathy
2) Vesicular rash beginning on trunk and spreading to face and extremities with lesions of different age.
3) Rash preceded by cough, coryza and conjunctivitis, beginning at head and moves down to include trunk, hands and feet (red spots with blue/white clearing in buccal mucosa)
4) Erythematous, sand-paper rash with fever and sore throat
5) Macular rash all over body several days after a fever in infants
6) Vesicular rash on palms and soles, with ulcers in the oral mucosa
7) "Slapped cheeks" rash on face |
|
Definition
1) Rubella (Togavirus)
2) Chickenpox from VZV (HHV-3)
3) Measles from Rubeola/Measles (Morbillivirus)
4) Scarlet fever from S. pyogenes (group A strep, beta hemolytic)
5) Roseola from HHV-6 (dsDNA virus)
6) Hand-foot-mouth in Cocksackie A (Paramixovirus)
7) Erythemia infectiosium in Parvovirus B19 (ssDNA virus)
- hydropis fetalis in pregnant women! |
|
|
Term
What is the typical childhood presentation of each of the following?
1) Rubella (Togavirus)
2) Chickenpox from VZV (HHV-3)
3) Measles from Rubeola/Measles (Morbillivirus)
4) Scarlet fever from S. pyogenes (group A strep, beta hemolytic)
5) Roseola from HHV-6 (dsDNA virus)
6) Hand-foot-mouth in Cocksackie A (Paramixovirus)
7) Erythemia infectiosium in Parvovirus B19 (ssDNA virus)
- hydropis fetalis in pregnant women! |
|
Definition
1) Rash beginning at head and moving down to trunk, with post-auricular lymphadenopathy
2) Vesicular rash beginning on trunk and spreading to face and extremities with lesions of different age.
3) Rash preceded by cough, coryza and conjunctivitis, beginning at head and moves down to include trunk, hands and feet (red spots with blue/white clearing in buccal mucosa)
4) Erythematous, sand-paper rash with fever and sore throat
5) Macular rash all over body several days after a fever in infants
6) Vesicular rash on palms and soles, with ulcers in the oral mucosa
7) "Slapped cheeks" rash on face |
|
|
Term
Name the organism that causes the clinical features described in each STD case.
1) Painless chancre
2) Fever, lymphadenopathy, skin rashes and condylomata lata
3) Urethritis and Epididymitis with creamy purulent discharge
4) Genital warts, koilocytes
5) Jaundice |
|
Definition
1) Primary syphilis (Treponema pallidum)
2) Secondary syphilis
3) Gonorrhea (N. gonorrhoeae)
4) Condylomata acuminata (HPV 6, 11)
5) Hepatitis B (HBV) |
|
|
Term
Name the organism that causes the clinical features described in each STD case.
1) Noninflammatory, malodorous discharge with a fishy smell, a positive whiff test, and clue cells on biopsy
2) Opportunistic infections and Kaposi's sarcoma
3) Vaginitis, strawberry-colored mucosa and organisms with corkscrew motility on wet prep
4) Painful genital ulcers with inguinal adenopathy
5) Painful penile, vulvar or cervical vesicles and ulcers, often presenting with fever, headache and myalgia |
|
Definition
1) Bacterial vaginosis (Gardnerella vaginalis)
- not exclusively an STD
2) AIDS (HIV)
3) Trichomoniaisis (Trichomonas vaginalis)
4) Chancroid (Haemophilus ducreyi (so painful, you cry)
5) Genital herpes (HSV-2) |
|
|
Term
Name the organism that causes the clinical features described in each STD case.
1) Urethritis, cervicitis, conjunctivitis, PID and Reiters syndrome
2) Urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis and creamy purulent discharge
3) Gummas, general paresis, aortitis and Argyll Robertson pupils
4) Infection of lymphatics. Genital ulcers, lymphadenopathy and rectal strictures.
5) Painful genital ulcers with inguinal adenopathy
6) Genital warts |
|
Definition
1) Chlamydia trachomatis (D-K)- reactive arthritis
2) N. gonorrhoeae
3) Tertiary syphilis (also Tabes dorsales)
4) Lymmphogranuloma venereum (C. trachomatis L1-L3)
5) Haemophilus ducreyi (so painful you do cry)
6) HPV 6, 11 |
|
|
Term
| What bugs cause Pelvic inflammatory disease and how does it present? |
|
Definition
"Cervical motion tenderness (chandelier sign) with purulent cervical discharge"
Can lead to Fitz-Hugh-Curtis syndrome- with infection of the liver capsule and "violin string" adhesions of parietal peritoneum to liver
1) Chlamydia trachomatis (subacute, undiagnosed)
- most common STD in US
2) N. gonorrhoeae (acute) |
|
|
Term
Which of the following is NOT seen in Pelvic inflammatory disease?
1) Salpingitis
2) Endometritis
3) Cervical motion tenderness
4) Cystitis
5) Tubo-ovarian abscesses
6) Hydrosalpinx |
|
Definition
4- bladder inflammation is not characteristic
**Salpingitis is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain and adhesions**
C. trachomatis or N. gonorrhoeae are top bugs! |
|
|
Term
| Why, if present, is Salpingitis a worrying finding in PID? |
|
Definition
C. trachomatis or N. gonorrhoeae
Salpingitis is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain and adhesion |
|
|
Term
Name the nosocomial pathogen associated with each of the following risk factors.
1) Newborn nursery
2) Urinary catheterization
3) Respiratory therapy equipment
4) Renal dialysis unit
5) Hyperalimentation (overeating)
6) Water aerosols |
|
Definition
Most common causes of nosocomial infections are E.coli (UTI) and S. aureus (wound)
1) CMV, RSV
2) E. coli, Proteus
3) Pseudomonas AERuginosa
4) HBV
5) Candida
6) Legionella |
|
|
Term
In a clinical history of a child, you discover that they have not been immunized.
What rashes, neurological and respiratory bugs should you be on the look out for? |
|
Definition
MMR, H. influenza B, Polio, Diptheriae
1) Rashes
- "Starts at head and moves down with postauricular lymphadenopathy" (Rubella)
- "Starts at head and moves down, preceeded by cough, coryza, conjunctivitis and Koplik spots" (Measles/paramixovirus)
2) Neuro
- Meningitis (H. influenza type B)
- Myalgia and paralysis (polio)
3) Respiratory
- Pharyngitis: Gray oropharyngeal exudate with obstructive pseudo-membranes and painful throat (C. pertussis)
- Epiglottitis: Fever with dysphagia, drooling and difficulty breathing due to edamatous "cherry red" epiglottis (H. influenza B) |
|
|
Term
Why might an un-immunized child present with each of the following?
1) "Rash that starts at head and moves down, along with postauricular lymphadenopathy"
2) "Rash that starts at head and moves down, preceeded by cough, coryza, conjunctivitis and Koplik spots"
3) Microbes colonizing nasopharynx cause Meningitis
4) Myalgia and paralysis
5) Pharyngitis: "Gray oropharyngeal exudate with obstructive pseudo-membranes and painful throat"
6) Epiglottitis: "Fever with dysphagia, drooling and difficulty breathing due to edamatous "cherry red" epiglottis |
|
Definition
1) Rubella (Togavirus)
2) Measles (Paramixo, Rubeola virus)
3) H. influenza type B
4) Poliovirus (picornavirus-enterovirus)
5) Diptheria
6) H. influenza type B |
|
|
Term
Lets do some quick associations.
1) Pus, empyema, abscess
2) Pediatric infection
3) Pneumonia in CF
4) Burn infection
5) Branching rods in oral infection, with sulfur granules |
|
Definition
1) S. aureus
2) H. influenzae (including epiglottitis)
3) Pseudomonas aeruginosa
4) Pseudomonas aeruginosa
5) Actinomyces israelii |
|
|
Term
Lets do some quick associations.
1) Trauma open wound
2) Surgical wound
3) Dog or cat bite
4) Currant jelly sputum
5) Positive PAS stain
6) Sepsis/meningitis in newborn |
|
Definition
1) C. perfringens
2) S. aureus
3) Pasteurella multicoda
4) Klebsiella
5) Tropheryma whippelii (Whipple's disease)
6) Group B strep (agalactiae) |
|
|
Term
Lets do some quick associations.
1) Health care provider infection
2) Fungal infection in diabetic
3) Asplenic patient
4) CGD
5) Neutropenic patients
6) Bilateral Bell's palsy |
|
Definition
1) HBV (needle stick)
2) Mucor or Rhizopus spp.
3) S. Pneumoniae, H. influenza, N. meningitidis
4) Catalase-positive microbes (PLACESS)
5) Candida albicans (systemic), Aspergillus
6) Borrelia burdorferi (Lyme) |
|
|
Term
Which antibiotics exploit the following mechanisms of action?
1) Inhibition of peptidoglycan cross-linking (cell wall synthesis)
2) Block peptidoglycan synthesis (cell wall)
3) Block nucleotide synthesis
4) Block DNA topoisomerases |
|
Definition
1) Penicillin, methicillin, ampicillin, piperacillin, cephalosporins, aztreonam, imipenem
2) Bacitracin, vancomycin
3) Sulfonamides, tremethoprim
4) Flouroquinolones (Floxacins and Nalidixic acid) |
|
|
Term
Which antibiotics exploit the following mechanisms of action?
1) Block mRNA synthesis
2) Damage DNA
3) Block 50s subunit
4) Block 30S subunit |
|
Definition
1) Rifampin
2) Metronidazole
3) Cloramphenicol, Macrolides, Clindamycin, Streptogramin (quinupristin, dalfopristin), Linezolid
4) Aminoglycosides, Tetracyclines |
|
|
Term
| What is the mechanism of action and resistance associated with the antibiotic used to treat gram-positives (S. pnuemo, S. pyogenes, Actinomycyes) and syphilis), with bactericidal action against gram-positive cocci, gram-positive rods, gram-negative cocci and spirochetes? |
|
Definition
Penicillin (G is IV and V is oral)
1) Beta-lactam antibiotic that binds PBPs, blocks transpeptidase cross-linking of peptidoglycan and activates autolytic enzymes
2) Beta lactamases cleave ring (similar to Ampicillin, Amoxicillin) |
|
|
Term
What types of toxicities are associated with each of the following Beta lactam antibiotics?
1) Penicillin
2) Methicillin
3) Ampicillin
4) Ticarcillin |
|
Definition
1) Hypersensivity (type 1) and hemolytic anemia (type II)
2) Hypersensitivity, Interstitial nephritis (not true of other penicillinase-resistant PNCs)
3) Hypersensitivity, apicillin rash, Pseudomembranous colitis (C. dif)
4) Hypersensitivity |
|
|
Term
| Why might you give a patient Methicillin or Nafcillin instead of Penicillin G? |
|
Definition
"Use naf for staph"
Penicillinase-resistant PCN drugs are used for non-MRSA staph infections
Bulky R group on these drugs protects against beta lactamases
With methicillin, watch out for interstitial nephritis! |
|
|
Term
| Why might you give a patient Ampicillin or Amoxicillin instead of Penicillin G? |
|
Definition
"ampicillin/amoxicillin HELPSS kill enterococci"
Aminopenicillins have wider spectrum (H. influenzae, E. coli, Listeria, Proteus, Salmonella, Shigella, enterococci)
** often combined with clavulinic acid to protect against beta-lactamases **
(Amoxicillin has better oral bioavailability) |
|
|
Term
| Which drugs are known to increase risk of C. dif diarrhea? |
|
Definition
| Clindamycin and Ampicillin |
|
|
Term
| Why might you give a patient Ticarcillin, Carbenicillin or Piperacillin instead of Penicillin G? |
|
Definition
"TCP: Takes Care of Pseudomonas"
Pseudomonas and gram-negative rods
**Use with clavulinic acid, to protect against beta lactamases** |
|
|
Term
| What are the beta-lactamase inhibitors? |
|
Definition
Used to protect antibiotic from penicillinase
CAST
1) Clavulinic Acid
2) Sulbactam
3) Tazobactam |
|
|
Term
What is the coverage of each of the following?
1) Cefazolin
2) Ceftriaxone
3) Cefuroxime
4) Ceftazidime
5) Cefepime |
|
Definition
1) 1st generation (Cefazolin and Cephalexin)
- PEcK: gram negative cocci (Proteus, E. coli, Klebsiella)
2) 3rd generation (Cefotaxime and Ceftazidime also 2nd generation)
- Serious gram negatives including Meningitis and Gonorrhea (Neisseria)
3) 2nd generation (Cefoxitin, Cefaclor and Cefuroxime)
- gram positive cocci (HEN PEcKS)
- H. inluenza, Enterobacter, Neiserria, Proteus, E. coli, Klebsiella and Serratia
4) 3rd generation
- Pseudomonas
5) 4th generation
- Increased activity against Pseudomonas and gram-positives |
|
|
Term
| Why might a physician choose a cephalosporin instead of a penicillin drug and what are the side effects? |
|
Definition
More resistant to beta-lactamases (also, if you need specfic coverage for meningitis or pseudomonas)
2) SE
- Hypersensitivity
- vitamin K deficiency
- Cross-hypersensitivity with PCN (5-10%)
- Increased nephrotoxicity of aminoglycosides
- Disulfiram-like reaction with ethanol (cefamandole) with acute sensitivity |
|
|
Term
| Which organisms are NOT covered by cephalosporins? |
|
Definition
they are LAME!
1) Listeria- Use Ampicillin/Amoxicillin
2) Atypicals (C,M)- Tetracycline, Macrolides
3) MRSA- vancomycin
4) Enterococci- Ampicillin/amoxicillin |
|
|
Term
Which cephalosporines treat each of the following?
1) Meningitis and Gonorrhea
2) Pseudomonas
3) MRSA
4) Serratia
5) Proteus |
|
Definition
1) Ceftriaxone (3rd generation)
2) Ceftazadime (3rd) or Cefepime (4th)
3) NONE
4) Cefoxitin, Cefaclor or Cefuroxime (2nd)
5) PEcK- Cephazolin/Cephalexin (1st) or 2nd |
|
|
Term
| What bugs to 2nd generation cephalosporins treat? |
|
Definition
Cefoxitin, Cefaclor, Cefuroxime
HEN PEcKS
H. influenza, Enterobacter, Neisseria, Proteus, E. coli, Klebsiella, Serratia
**1st gen treats PEcK (Cephazolin, Cephalexin) |
|
|
Term
| Why might you give a patient Aztreonam? |
|
Definition
Renal insufficiency (can't take aminos) or PCN allergy
- Monobactam resistant to beta-lactamases (binds PBP3)
- Hits gram-negative rods ONLY (E. coli, Klebsiella, Salmonella, ect). |
|
|
Term
| What are the Carbapenem antibiotics and how are they used? |
|
Definition
Imipenem/cilastatin and Meropenem are broad-spectrum, beta-lactamase-restant drugs that treat it all, but with side effects
**Cilastatin inactivates dihydropeptidase I in renal tubules, which inactivates Imipenem**
- GI distress, skin rash, CNS toxicity (seizures) at high plasma levels.
- Meropenem has reduced seizure risk and is stable to dihydropeptidase in renal tubules, so it is preferred |
|
|
Term
| Why give Cilastatin with Imipenem and why give Meropenem instead? |
|
Definition
1) Cilastatin innactivates dihydropeptidase I in renal tubules, which inactivates Imipenem
2) Meropenem has lower CNS seizure risk and is stable to dihydropeptidase I in kidney |
|
|
Term
Why might you give a patient Vancomycin?
What are the toxicities you are worried about? |
|
Definition
Vancomycin binds D-ala D-ala portion of cell wall precursors and prevents cell wall mucopeptide formation (bactericidal)
1) Gram positives (mainly MRSA, C. dif and Enterococci)
2) Well tolerated and does NOT have many problems
- Nephrotoxicity, Ototoxicity, Thrombophlebitis, diffuse flushing "red man" |
|
|
Term
| What might you do to prevent "red man syndrome" when giving Vancomycin to treat an enterococcal infection? |
|
Definition
Pre-treat with antihistamines and slow infusion rate of Vancomycin.
Still issue of Oto, Nephro and Thrombophlebitis |
|
|
Term
| How do certain enterococci become resistant to vancomycin? |
|
Definition
Amino acid change of D-ala D-ala to D-ala D-lac
"Pay back 2 D-alas for VANdalazing" |
|
|
Term
| What are the protein synthesis inhibitor antibiotics: which are bactericidal and which are bacteristatic? |
|
Definition
Buy AT 30. CCEL at 50"
Aminoglycosides are the only "cidal" protein synthesis inhibitors
1) 30s
- Aminoglycosides (cidal)
- Tetracyclines (static)
2) 50S
- Clindamycin (static)
- Erythromycin (macrolide- static)
- Linezolid (variable |
|
|
Term
Which of the following drugs is bactericidal?
1) Aminoglycosides
2) Macrolides
3) Linezolid
4) Clindamycin
5) Tetracyclin |
|
Definition
1- Aminoglycosides are "cidal" and prevent formation of the initiation complex
All are protein-synthesis inhibitors
AT (30) CEL (50) |
|
|
Term
| How do each of the following protein-synthesis inhibitor antibiotics work? |
|
Definition
1) Aminoglycosides
- Prevent initation complex formation at 30s subunit and cause misreading of mRNA
- bactericidal
2) Tetracycline
- Inhibit tRNA binding to A-site by binding 30S
3) Macrolides
- Inhibit translocation by binding 23S rRNA of 50S subunit
- Static
4) Chloramphenicol/Clindamycin
- Block peptidyl transferase at 50S, preventing peptide bond formation
- Static
5) Linezolid
- Inhibit 50S and 30S association by binding 50S
- variable cidal/static |
|
|
Term
| Why might you use/avoid aminoglycoside antibiotics? |
|
Definition
"Mean" GNATS canNOT kill anaerobes
Gentamycin, Neomycin, Amikacin, Tobramycin, Streptomycin
1) Use against gram-negative rods (synergism with beta lactams)
**Neomycin for bowel surgery**
2) Nephro, Oto and Teratogen, as well as being innefective against anaerobes (need O2 for uptake) |
|
|
Term
| Which drugs should you NEVER give with aminoglycosides if possible? |
|
Definition
| Cephalosporins: combined nephrotoxicity |
|
|
Term
| What are the Tetracyclines and when are they used? |
|
Definition
Tetracycline, Doxicycline, Demeclocycline, Minocycline
1) Bind 30S ribosomal subunit and prevent tRNA binding at A site.
- Good for Borrelia burdorferi, M. pneumoniae and intracellular pathogens (Chlamydia and Rickettsia)
2) Don't give in pregnancy.
Plasmid encoded influx/efflux pumps can cause resistance |
|
|
Term
| Which bugs are hit by Doxycycline and what are the potential toxicities? |
|
Definition
**Fecal elimination, so can be used in renal failure**
1) Borellia burdorferi (Lyme), M. pneumoniae (atypical pneumonia), Intracellular bugs (Chlamydia and Rickettsia)
2) GI, Photosensivity, inhibition of bone growth and stained teeth in kids
- Teratogen |
|
|
Term
| What important dietary considerations are important to remember when treating Lyme's disease with Doxicycline? |
|
Definition
| Do NOT take with Milk, Iron or Antacids, because it cannot be absorbed in the intestine |
|
|
Term
| Why is the primary use of Demeclocycline? |
|
Definition
ADH anatagonist used as diuretic for SIADH
Tetracycline (30S inhibitor) |
|
|
Term
| What are the Macrolides and when are they used? |
|
Definition
Erithromycin, Azithromycin, Clarithromycin
50S inhibitors that bind 23s rRNA and prevent translocation
1) Atypical pneumonia (chlamydia, mycoplasma, legionella)
- URI
- STD
- gram-positive cocci (allergy to PCN)
- Neisseria
2) Watch out for prolonged QT interval (erythromycin), GI, acute cholestati hepatitis, eosinophilia, skin rashes |
|
|
Term
| What drugs should be carefully tracked when adding a Macrolide like Erythromycin to a regimen? |
|
Definition
Increase serum concentration of
1) Oral anti-coagulants
2) Theophyllines (anti-platelet) |
|
|
Term
What drug is associated with each of the following mechanisms of resistance?
1) Methylation of 23S rRNA binding site
2) Transferase enzymes that inactivate drug by acetylation, phosphorylation and adenylation
3) Amino acid exchange of D-ala D-ala to D-ala D-lac
4) Beta lactamases
5) Plasmid-encoded efflux/influx pumps
6) Plasma-endcoded acetyltransferase
7) Altered bacterial dihydropteroate synthetase and increased PABA synthesis |
|
Definition
1) Macrolides (50S protein synthesis)
2) Aminoglycosides (30S)
3) Vancomycin
4) Penicillin, Ampicillin (need clavulinic acid), Cephalosporins
5) Tetracyclines
6) Chloramphenicol
7) Sulfonamides |
|
|
Term
What is the drug of choice in the developing world to treat meningitis?
Why is it avoided in the US? |
|
Definition
1) Chloramphenicol (50S ribosome blocking peptide bond synthesis like Clindamycin)
- hits H. influenza, Neisseria, Strep. pneumo
2) Toxicities
- Anemia (dose dependent)
- Aplastic anemia (dose independent)
- Gray baby syndrome (premature infants that lack liver UDP-glucuronyl transferase) |
|
|
Term
Why might you use the drug that inhibits bacterial protein synthesis by binding the 50S ribosomal subunit and preventing peptide bond formation? (hint. NOT chloremphenicol)
What are the toxicities? |
|
Definition
Clindamycin hits anaerobes above the diaphragm (vs. metronidazole that hits anaerobes below)
1) Anaerobes (bacteroides, clostridium)
in aspiration pneumonia or lung abscesses
2) Pseudomembranous colitis (C. dif), fever and diarrhea |
|
|
Term
| Which drugs treat anaerobes above and below the diaphragm? |
|
Definition
Avove= Clindamycin (lung abscess or aspiration pneumonia)
Below- Metronidazole (UTI)
- Also hits Giardia, Entamoeba, Trichomonas, Garnerella and H. pylori (with Bismuth and amoxicillin/tetracycline) |
|
|
Term
Which class of antibiotics inhibits DNA synthesis by producing PABA antimetabolites that inhibit dihydropteroate synthetase?
What are the toxicities and uses? |
|
Definition
Sulfonamides (SMX, sulfisoxazole, sulfadiazine)= Bacteriostatic
1) Gram positive, gram-negative, Nocardia, Chlamydia
- Triple sulfas or SMX for simple UTI
2) Hypersensivity, G6PD deficiency, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infants, dispace other drugs from albumin (warfarin) |
|
|
Term
| Which drugs inhibit bacterial dihydrofolate reductase, why would you use them and what are their toxicities? |
|
Definition
TMP: "Treats marrow badly"
1) Trimethoprim (like MTX, with leucovorin rescue)
- Bacteriostatic
2) Used with SMX to make Bactrim, which produces a sequential blockage of folate synthesis that is good for UTIs, Shigella, Salmonella, PCP
2) Megaloblastic anemia (folate), Leukopenia, Granulocytopenia
**Leucovorin rescue** |
|
|
Term
| Which drugs inhibit DNA gyrase, why would you use them and what are their toxicities? |
|
Definition
FlouroquinoLONES hurt attachments to BONES
**NO antacids**
Cipro, Nor, Levo, Oflo, Spar, Moxi, Gatiflox, Enoxaflocacin and Nalidixic acid (quinolone): BACTEROCIDAL
1) Hit gram-negative rods of urinary and GI tracts (including pseudomonas), Neiserria, some gram-positives
2) GI, superinfection, skin rash, headache, dizziness
- No pregant women or children because of cartilage damage, cramps and myalgia
- Adults >60 or those on predisone have tendonitis and possible rupture. |
|
|
Term
| Which antibiotics are contraindicated in Pregnancy? |
|
Definition
1) Aminoglycosides
2) Tetracyclines
3) Flouroquinolones |
|
|
Term
| Which drugs inhibit damage DNA via free radical metabolites, why would you use them and what are their toxicities? |
|
Definition
Metronidazole- bacteriacidal and anti-protozoal
1) GET GAP on the Metro
- Giardia, Entamoeba, Trichomonas, Gardnella, Anaerobes, h. Pylori
2) Disulfiram-like reaction with alcohol (like cephalosporins); headache, metallic taste |
|
|
Term
| How is PUD from H. pylori treated? |
|
Definition
Triple therapy
1) PPi, Bismuth salt
2) Amoxicillin/Tetracycline
3) MEtronidazole |
|
|
Term
Which drugs are associated with each of the following mechanisms of resistance?
1) Plasma-endcoded acetyltransferase
2) Altered bacterial dihydropteroate
3) Chromosome-encoded mutation in DNA gyrase
4) D-ala D-ala to D-ala D-lac |
|
Definition
1) Chloramphenicol (meningitis)
2) Sulfonamide (+, -, nocardia and chlamydia)
3) Flouroquinolones
4) Vanco (gram +: MRSA, enterococci, C. dif) |
|
|
Term
| Which drugs are used to treat each of the mycobacterial species prophylactically and etiologically. |
|
Definition
1) TB
- Isoniazid (prophylaxis)
- RIPE (Rifampin, Isoniazid, Pyraziamide, Ethambutol)
2) MAC
- Azithromycin (prophylaxis)
- Azithromycin, rifampin, ethambutol, streptomycin
3) M. leprae
- No prophylaxis
- Dapsone, Rifampin, Clofazimine |
|
|
Term
| How do each of the drugs used to treat TB work and what are their toxicities? |
|
Definition
RIPE
1) Rifampin
- Inhibit DNA-dependent RNA polymerase
- Hepatotoxicity and drug interactions (P-450), with benign orange bodily fluids
2) Isoniazid
- Inhibit mycolic acid synthesis (requires bacteria catalase-peroxidase, KatG, for activation
- Neuro, hepato, lupus (prevent Neuro and Lupus with B6)
3) Pyrazinamide
- Converted to pyrazinoic acid, acidifying lumen and inhibiting mycolic acid (mycobacterial fatty acid synthase I)
- Hyperuricemia and hepatotoxicity
4) Ethambutol
- Decrease carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase
- Optic neuropathy (red-green color blindness) |
|
|
Term
| What is the clinical utility and toxicity associated with the drug that inhibits mycolic acid synthesis following activation by bacteria catalase-peroxidase (KatG)? |
|
Definition
Isoniazid
1) TB- only agent as sole prophylaxis
2) INH Injures Neurons and Hepatocytes
- Prevent neurotoxicity and lupus with B6 |
|
|
Term
| A patient is receiving prophylactic treatment for TB. What vitamin might you put them on as well? |
|
Definition
| Prophylaxis is Isoniazid, so you need to give B6 to prevent neurotoxicity and lupus. |
|
|
Term
| What is the clinical utility and toxicity associated with the drug that Inhibits mycobacterial fatty acid synthease I by acidifying phagolysosomal pH?? |
|
Definition
Pyrazinamide (converted to pyrazinic acid, which acidifies pH)
1) TB (part of RIPE)
2) Hyperuricemia and Hepatotoxicity |
|
|
Term
| What is the clinical utility and toxicity associated with the drug Inhibits DNA-dependent RNA polymerase in the treatment of leprosy? |
|
Definition
Rifampin
4 R's
1) RNA polymerase inhibitor
2) Revs up microsomal P-450
3) Red/orange body fluids
4) Rapid resistance if used alone
1) Use
- Part of RIPE therapy in TB
- Delays Dapsone resistance in Leprosy
- Used in phophylaxis for Meningitis in contacts of children with Hemophilus influenzae type B.
- Used in MAC in HIV patients
2) Toxicity
- Drug interactions (CYP-450)
- Red/orange fluids
- Hepatotoxicity |
|
|
Term
| What is the clinical utility and toxicity associated with the drug that inhibits carbohydrate polymerization of mycobacterium cell walls by blocking arabinosyltransferase? |
|
Definition
Ethambutol
1) Use
- Part of RIPE
- Also in MAC treatment (with Azithromycin, Rifampin and Streptomycin)
2) Optic neuropathy (red-green color blindness) |
|
|
Term
What is the appropriate anti-microbial prophylaxis for the following?
1)Meningococcal
2) Gonorrhea
3) Syphilis
4) H/x of recurrent UTI
5) Endocarditis with surgical or dental procedures |
|
Definition
1) Ciprofloxacin (drug of choice), rifampin, minocycline
2) Ceftriaxone
3) Benzathine penicillin G
4) TMP-SMX
5) Penicillins |
|
|
Term
What drugs should you use prophylacticly in HIV when CD4 count drops below,
1) <200
2) <100
3) <50 |
|
Definition
1) PCP (TMP-SMX)
**If patient can't handle Bactrim, use aerosolized pentamide, but it will NOT work for Toxo**
2) PCP and TOXO (TMP-SMX)
3) MAC (Azithromycin)
- If they get it, treat with azithromycin, rifampin, ethambutol and streptomycin |
|
|
Term
| How do you treat MRSA and VRE, respectively? |
|
Definition
1) MRSA- vancomycin
2) VRE- linezolid and streptogramins (quinupristin/dalfopristin) |
|
|
Term
What is the appropriate empiric therapy for CA pneumonia in the following settings?
1) Outpatient
2) Inpatient
3) ICU |
|
Definition
1) Macrolides
2) Flouroquinolones
3) Beta lactam + (FQ or Azithromycin) |
|
|
Term
What are the major mechanisms of action of the following anti-fungal drugs?
1) Amphotericin B
2) Caspofungin
3) Naftifine
4) Terbinafine
5) Fluconazole
6) 5-flucytosine
7) Nystatin |
|
Definition
1) Binds ergosterol (unique to fungi), forming membrane pores that allow leakage of electrolytes ("tears holes")
2) Inhibits cell wall synthesis by inhibiting beta-glucan
- Aspergillus (invasive), candida
3) Inhibits fungal enzyme squalene epoxidase, impairing lanosterol synthesis
- Topical Tinea infections (pedis, corporas, cruris)
4) Inhibit squalene epoxidase
- Dermatopytosis (onchomycosis- finger and toes)
5) Inhibit fungal sterol (ergosterol) synthesis, by inhibiting P-450 enzyme that converts lanosterol to ergosterol
- Crypto in AIDS and Candida
6) Inhibits DNA synthesis by conversion to 5-flourouracil by cytosine deaminase
- Systemic fungal infections like Crypto in combination with Amphotericin
7) Topical version of Amphotericin, too toxic for systemic use
- Oral candida (swish and swallow) and diaper rash/vaginal candidiasis |
|
|
Term
| What is the clinical utility and toxicity associated with the drug that inhibits DNA synthesis by conversion to 5-florouracil by cytosine deaminase? (in terms of fungal infections). |
|
Definition
5-FU
1) Systemic fugal infections (Cryptococcus) in combination with amphotericin B
2) Nausea, vomiting, diarrhea, bone marrow suppression |
|
|
Term
| What is the clinical utility and toxicity associated with the drug that inhibits the synthesis of Beta-glucan? |
|
Definition
Caspofungin prevents fungal cell wall synthesis
1) Invasive aspergillosis, Candida
2) GI upset and flushing |
|
|
Term
| What is the clinical utility of each of the following azoles and what are the concerning toxicities associated with their use? |
|
Definition
Azoles inhibit fungal sterol (ergosterol) synthesis, by inhibiting the P-450 enzyme that converts lanosterol to ergosterol
- Used for systemic mycoses and can inhibit hormone synthesis (Gynecomastia), liver dysfunction (CYP-450 inhibition), fever and chills
1) Fluconazole: Crypto meningitis in AIDs and Candida
2) Ketoconazole: Blastomycoses, Coccidio, Histo, Candida, hypercortisol
3) Clotrimazole: Topical fungal
4) Miconazole: Topical fungal |
|
|
Term
What is the drug of choice for each of the following?
1) Oral thrush
2) Cryptococcal meningitis in AIDS
3) Invasive aspergillosis
4) Histoplasma (serious systemic)
5) Onychomycosis on the fingers and toes |
|
Definition
1) Nystatin (topical amphotericin) "shake and swallow"
- Also for diaper rash or vaginal candidiasis
2) Fluconazole
- Also for candida
3) Caspofungin (inhibits beta-glucan in cell wall synthesis)
- Also candida
4) Amphotericin B for serious systemic infections
- Ketoconazole also hits Histo
5) Terbinafine (inhibits squalene epoxidase)
- All dermatophytoses |
|
|
Term
What is the coverage of Amphotericin B and what do you supplement it with when treating a fungal infection?
What are the toxicities? |
|
Definition
Binds ergosterol and pokes holes in fungal membrane
1) Serious systemic mycoses
- Histo, Blasto, Coccidio, Crypto, Aspergillus, Candida, Mucor (DKA), meningitis (intra-thecally with or without flucytosine)
2) Supplement with K and Mg because of altered renal tubule permeability (use to hydrate)
3) Fever/chills (shake and bake), hypotension, nephrotoxicity, arrythmia, anemia, IV phlebitis ("amphoterrible")
**Liposomal amphotericin reduces toxicity** |
|
|
Term
| Which drug is commonly given with Amphotericin B to treat cyrptococcal meningitis? What are its toxicities? |
|
Definition
Flycytosine (converted to 5-florouracil by cytosine deaminase) inhibits DNA synthesis
Nausea, vomiting, diarrhea, bone marrow suppression |
|
|
Term
Patient with a fungal infection of their toenails is receiving treatment and presents with visual disturbances.
You notice some abnormal LFTs and you decide to switch his drug regimen to a drug that interferes with microtubule function. You now monitor him closely, since he is also taking anti-coagulation.
What are these 2 drugs and how do they work? |
|
Definition
1) Visual disturbances + LFTs= Terbinafine (inhibits squalene epoxidase)
2) Griseofulvin inhibits microtubule function, disrupting mitosis by depositing in keratin-containing tissues (nails)
- Teratogen, carcinogenic, confusion, headaches
- Increases P450 metabolism of warfarin |
|
|
Term
How might you treat a Toxoplasmosis infection?
What else does this drug cover? |
|
Definition
| Pyrimethamine for Toxo and P. falciparum (malaria) |
|
|
Term
How do you treat each of the following Trypanosoma species?
1) T. cruzi
2) T. brucei |
|
Definition
1) Chagas disease: Nifurtimox (nitro anion radical metabolites)
2) African sleeping sickness: Suramin and Melarsoprol
- Suramin (anti-cancer, growth factor inhibitor)
- Melarsoprol |
|
|
Term
Soldier returning home from Iraq presents with skin ulcers. He reports being bitten by sandflies about 8 weeks ago.
What do you do? |
|
Definition
Leshminiasis (Trypanosoma)
Give him sodium stribogluconate |
|
|
Term
| What is the prophylaxis/treatment of Plasmodium species and what are the important side effects? |
|
Definition
1) Mephloquine for prophylaxis
2) Chloroquine for disease (blocks plasmodium heme polymerase)
- Quinine for resistant species in combination with pyrimethamine/sulmonamide
- Retinopathy and G6PD hemolysis |
|
|
Term
Which of the following drugs is NOT anti-heminthic, and what do the others treat?
1) Mebendazole
2) Chloroquine
3) Pyrantel pamoate
4) Ivermectin
5) Diethycarbamazine
6) Praziquantel |
|
Definition
2- Chloroquine inhibits heme polymerase in Plasmodium species (falciparum, vivax/ovale)
1) Bendazoles for intestinal Nematodes (Enterobius, Ascaris, Strongiloides, Ancyclostoma, Necater)
3) Pyrantel pamoate also for intestinal nematodes
4) Ivermectin for Onchocerca volvulus (river blindness)
5) Diethylcarbamazine Tissue nematodes like Loa Loa, Wuchereria, Toxocana canis
6) Praziquantel
- Cestodes (tapeworm) like Taenia solium Diphylloborthrium, Echinooccus
- Trematodes (fluke) like Schistosoma, Glonorchis, Paragoniimus |
|
|
Term
What is the first-line anti-viral treatment of choice for each of the following?
1) Influenza (A or B)
2) RSV
3) CMV (immunocompromised
4) Parkinson's
5) EBV |
|
Definition
1) Zanamivir, Oseltamivir
- Inhibits influenza NA, decreasing release of progeny
2) Ribavirin (also from chronic HCV)
- Inhibits guanine nucleotides by competitively inhibiting IMP dehydrogenase
3) Ganciclovir (5'-monophosphate formed by a CMV viral kinase: triphosphate form preferentially inhibits viral DNA polymerase)
- Valganciclovir pro-drug has better oral bioavailability
- In Ganciclovir-resistant CMV, use Foscarnet or Cidovovir
4) Amantadine (blocks viral penetration/un-coating (M2 protein) and causes release of dopamine from intact nerve terminals
**Used to be used for infleunza A**
5) Acyclovir (Monophophorylated by HSV/VZV thymidine kinase. guanosine analog. Triphosphate formed by cellular enzymes. Inhibits viral DNA polymerase by chain termination)
- HSV, VZV (famcicyclovir), EBV |
|
|
Term
| What is the mechanism of action and toxicity associated with the drug that treats HSV-induced mucocutaneous and genital lesions, as well as encephalitis? |
|
Definition
Acyclovir for HSV-1, HSV-2, VZV (famciclovir) and EBV
1) Mechanism
- Drug is monophosphorylated by HSV/VZV thymidine kinase
- Guanosine analog becomes triphosphate form via cellular enzymes
- Triphosphate form inhibits viral DNA polymerase by chain termination
2) Toxicity
- Few serious
- Can develop resistant if lack of viral thymidine kinase |
|
|
Term
| What is the mechanism of action and toxicity associated with the drug that treats CMV as a first line option? |
|
Definition
Ganciclovir
**For ganciclovir-resistant CMV, use Foscarnet, or Cidofovir**
1) Mechanism
- 5'-monophophate formed by CMV viral kinase.
- Guanosine analog is converted to triphosphate form by celular kinases
- Inhibits viral DNA polymerase
2) Leukopenia, neutropenia, thrombocytopnea, renal toxicity (more toxic than acyclovir) |
|
|
Term
What are the drugs used to treat CMV retinitis in patients that have mutated CMV DNA polymerases or lack of CMV viral kinases?
What other uses are there for these drugs |
|
Definition
These factors make the viral Ganciclovir-resistant.
Both options have nephrotoxicity, so adjust in renal failure!
1) Foscarnet
- Binds pyrophosphate-binding site on viral DNA polymerase and inhibits it (does not require activation by viral kinase)
- Also good for Acyclovir-resistant HSV
2) Cidofovir- Give with probenecid, for nephrotoxicity
- Preferentially inhibits DNA polymerase, but does not require phosphorylation by viral kinase
- Also good for acyclovir-resistant HSV
- Long half-life |
|
|
Term
| Which antibiotics should be avoided in Pregnancy? |
|
Definition
Countless SAFe Moms Take Really Good Care
- Clarithromycin- embryotoxic
- Sulfonamides- Kernicterus
- Aminoglycosides- Ototoxicity
- Flouroquinolones- Cartilage damage
- Metronidazole- Mutagenesis
- Tetracycline- Discolored teeth/inhibited bone growth
- Ribavirin- teratogen
- Griseofulvin- teratogen
- Chloramphenicol- gray baby |
|
|
Term
| When should HAART therapy be started and what are the major regimen options? |
|
Definition
1) Start when patient presents with AIDS-defining illness (PCP, Toxo, ect), low CD4 count (<500) or high viral load.
2) 2NRTIs + 1 NNRTI or 1 protease inhibitor or 1 integrase inhibitor |
|
|
Term
| What are the major protease inhibitors and how do they work to treat HIV? Which is the only one that tends to increase serum concentrations of other drugs? |
|
Definition
Given with 2 NRTIs in AIDs patients
1) "Navir" drugs
- Lopinavir
- Atazanavir
- Darunavir
- Fosamprenavir
- Saquinavir
- Ritonavir (BOOST other drugs by inhibiting CYP-450)
2) HIV protease cleaves polypeptide products of HIV mRNA, and protease inhibitors prevent assembly of mature virions |
|
|
Term
| What are the major NRTIs and how do they work to treat HIV? Which drug is given as prophylaxis during pregnancy to reduce risk of fetal transmission? |
|
Definition
Give 2 of them with 1 NNRTI, 1 protease inhibitor or 1 integrase inhibitor
1) Drugs
- Tenofovir (TDF)
- Emtricitabine (FTC)
- Abacavir (ABC)
- Lamivudine (3TC)
- Zidovudine (ZDV, AZT)
- Didanosine (ddI)
- Stavudine (d4T)
2) Competitively inhibit nucleotide binding to RT and terminate the DNA chain (lack of 3'-OH group)
**Must be phosphorylated by thymidine kinase to be active**
3) ZDV during pregnancy |
|
|
Term
| What are the major NNRTIs and how do they work to treat HIV? |
|
Definition
Give with 2 NRTIs for AIDS
1) "VIR" drugs
- NeVIRapine
- EfaVIRenz
- DelaVIRdine
2) Bind RT at site different from NRTI and do not require phosphorylation by thymidine kinase (like NRTis) |
|
|
Term
| How does Raltegravir treat AIDs? |
|
Definition
Integrase inhibitor given with 2 NRTIs
Inhibits HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase
**Watch out for hypercholesterolemia** |
|
|
Term
What are the important toxicities associated with each group of HAART drugs?
1) Protease inhibitors (Navirs)
2) NRTIs
3) NNRTIs (VIR)
4) Integrase inhibitor (Raltegravir) |
|
Definition
1) Hyperglycemia, GI intolerance, Lipodystrophy
2) Bone marrow suppression (give G-CSF and EPO), peripheral neuropathy, lactic acidosis (nucleosides), rash (non-nucleosides), megaloblastic anemia (ZDV)
3) Same as NRTI
- Rash more common
4) Hypercholesterolemia |
|
|
Term
| Why give ZDV during pregnancy? What should you worry about? |
|
Definition
Prevent fetal transmission of AIDs, but watch out for megaloblastic anemia.
Also, all NNRTIs carry risk of
- bone marrow suppression (Give G-CSF and EPO), - peripheral neuropathy
- lactic acidosis
- rash |
|
|
Term
| Why might you give an AIDS patient taking HAART G-CSF and EPO? |
|
Definition
| NNRTIs cause bone marrow suppression and megaloblastic anemia (ZDV) |
|
|
Term
| How do interferon drugs work and why might you give them? |
|
Definition
Glycoproteins synthesized by virus-infected cells that block replication of both RNA and DNA viruses
**Watch out for neutropenia**
- IFN-a: Chronic hep B and C, Kaposis sarcoma
- IFN-b: NADPH oxidase deficiency (CGD), MS |
|
|
Term
Which of the following is an appropriate treatment for an HIV positive patient with a CD4 count of 400?
1) Zidovudine, Nevirapine and Raltegravir
2) Lamivudine, Emtricitabine and Stravudine
3) Tenofovir and Efavirenz
4) Abacavir, Ritonavir and Emtricitabine
5) Raltegravir, Delavirdine and Lopinavir |
|
Definition
4: 2 NRTIs (Abacavir and Emtricitabine) and + 1 Protease inhibitor (Ritonavir)
You need 2NRTIs + 1 NRTI or 1 protease inhibitor or 1 integrase inhibitor
1) 1 NRTI (ZDV), 1 NNRTI (Nevirapine), 1 Integrase (Raltegravir)
2) 3 NRTIs
3) 1 NRTI (Tenofovir) and 1 NNRTI (Efavirenz)
5) 1 integrase inhibitor (Raltegravir), 1 NNRTI (Delavirdine) and 1 protease inhibitor (Lopinavir) |
|
|
Term
Which of the following is an appropriate treatment for an HIV positive patient who presents with and AIDS defining lesion?
1) Raltegravir, Efavirenz, Tenofovir
2) Efavirenz, Tenovovir, Lopinavir
3) Lamivudine, Darunavir, Didanosine
4) Ritonavir, Abacavir, Nevirapine
5) Fosamprenavir, Emtricitabine, Raltegravir |
|
Definition
3: 2 NRTIs (Lamivudine, Didanosine) and 1 Protease (Darunavir)
Need 2NRTis and 1 of the others.
1) 1 NRTI (Tenofovir)I, 1NNRTI (Efavirenz), 1 Integrase (Raltegravir)
2) 1 NNRTI (Efavirenz), 1 NRTI (Tenofovir), 1 Protease (Lopinavir)
4) 1 Protease (Ritonavir), 1 NRTI (Abacavir), 1 NNRTI (Nevirapine)
5) 1 Protease (Fosamprenavir), 1 NRTI (Emtricitabine), 1 Integrase (Raltegravir) |
|
|
