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Micro Midterm
micro midterm
231
Microbiology
Undergraduate 4
02/19/2011

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Term
Which are the three domains in which prokaryotes as well as all living organisms are classified.
Definition
1.Bacteria- all pathogenic bacteria
2. Archea- type of bacteria but not associated with any disease.
3. Eukarya- Algae: protozoa. Fungi- Large parasites. Animalia, Plantae.
Term
Types of microscopes
Definition
1. Light Field- Resolution limited to wavelength of resolution. Visible light wavelength= 0.2 um.
2.Dark field- uses dark field condenser. used for visualizing small and slender organisms (spirochetes) Oblique source of light gives images against a dark field.
3. Fluorescent- source of light is ultraviolet.
4. Electron- transmission- sees internal details. Scanning- sees outer details. Scanning with flying spot of electrons.
Term
Gram Staining Procedure
Definition
Bacteria on glass slide-> heat fixed or dip in 95% ethano/methanol- 5 min. air dry -> stain (crystal or methyl violet)-> flood with PKI (Grams Iodine) solution -> wash with DH2)-> decolorize 95% (ethyl alcohol) -> counter stain (saffranin for 20-30 secs) Then blot dry and examine.
Term
Gram Negative/Positive Stains
Definition
Gram (+) Retains basic dye (violet)
Gram (-) Does not retain violet- red-pink.
Differences in G+ and G- are in cell wall.
Term
Shapes of Bacteria
Definition
Rod- Bacillus
Sphere- Coccus
Spiral or curved- Spirochete (spirillium, vibrio)
Term
Size of Bacteria and examples
Definition
Large: Spirochetes, Bacillus, Clostridium
Medium: Enterobacteriacea, pseudomonas
Small: Brucella, Pasteurella, Haemorphiles, Cocci.
Pinpoint- Rickettsia, Chlamydia, Mycoplasma.
Term
Structure: Capsule
Definition
Composed of polysaccharides and polypeptides.
Virulence- relationship
antiphagocytic activity
adherence to cells for colonization *in starvation situations, can consume plasmid for nutrition.
Term
Structure: Cell Wall
Definition
Composition- macetyl muranic acid, N-actylglucosamine. 20% weight in bacteria is cell wall.
Term
Function of Cell Wall
Definition
1. Rigid shape (peptidoglycans)
2. Prevents osmotic lysis
3. Responsible for virulence
4. Site of antibiotics action
5. G(+) thick peptidoglycan, G(-) Thin peptidoglycan.
Term
Structure: Flagella
Definition
(H antigens) for motility. Locomotion or motility. Spirochetes- axial filaments for locomotion. Capsulated bacteria are non-motile.
Term
Structure: Axial Filament
Definition
in spirochetes for mobility
Term
Structure: Fimbriae
Definition
Colonizing factor or adherence
Term
Structure: Pili
Definition
Conjugation: transfer of plasmids and genes in bacteria. Antibiotic resistance and toxic gene transfer.
Term
Structure: Endospores
Definition
(clostridium and bacillus anthracis) Resistance- spore coat- resistant to UV rays. Boiling and autoclaving will destroy endospores.
Term
Structure: Plasmids and chromosomal DNA
Definition
selective permeability and antigens and antibiotic actin site.
Term
Structure: Ribosomes
Definition
Site of protein synthesis. Antibiotic action site.
Term
Major cell wall differences between gram positive and gram negative bacteria
Definition
peptidoglycan, outer membrane
Term
Fungi
Definition
Multicellular filamentous mold
Term
Yeast
Definition
unicellular form
Term
Fungal Structures
Definition
1. Capsule- antiphagocytic
2. Cell wall- chitin, no peptidoglycans as seen in bacteria.
3. Cytoplasmic or plasma membrane.
Term
Target of Antifungal Drugs
Definition
Zymasterol and Ergosterol- sterols in cell wall of fungi.
Term
Based on nutritional requirements, all microorganisms can be grouped as:
Definition
a) photosynthetics - Cyanobacteria (blue-green algae)
b) autotrophs
c) heterotrophs – saprophytes. strict parasites. most pathogens
Term
Temprature based groups of bacteria
Definition
a)Psycrotrophs (20-30C) * examples: L. monocytogenes
b)mesophils (30-40C) * comprises all pathogens
c) thermophils (50-90 C)
Term
Chemical and Physical requirements of growth
Definition
Temperature, pH concnetration, CO2 Requirement, Oxygen requirement, Movement or Transport of Nutrients into the cell.
Term
Five groups based on O2 requirement- definitions
Definition
a)obligate aerobe- can only grow in air.
b)facultative anaerobe- all enterics
c)microaerophil- ex. Campylobacter fetus.
d)strict anaerobe- ex. Clostridium botulinum.
e)aerotolerant aerobes- ex. Lactobacilli
Term
Oxygen toxicity
Definition
enzyme to neutralize this. 1. superoxide dismutase. 2. catalase. 3. peroxidase.
Term
Transport of nutrients across plasma membrane of bacteria
Definition
1. Passive Transport- diffusion, osmosis.
2. Active transport- requires energy and carrier protein. *plasma membrane- selectively permeable.
3. Facilitated diffusion- requires carrier proteins. (group translocation (on found in bactera) Glucose outside the cell)
Term
Cellular metabolism
Definition
production energy. Synthesis of bacterial components- proteins, lipids, DNA, RNA, carbohydrates.
Term
Catabolism
Definition
(metabolism) degradation or decomposition or break down or hydrolysis of complex organic molecules. Produces energy- ATP. 1.Glycolysis
2. Krebs cycle
Term
Anabolism
Definition
synthesis of bacterial components
Term
Enzymes
Definition
Biological catalysts
Term
Protein
Definition
Carry all synthetic and decomposition reactions.
Term
Most ATP is produced by which pathway:
Definition
Electron transport chain
Term
Aerobic Respiration
Definition
Oxygen as final electron acceptor.
Term
Anaerobic respiration
Definition
Nitrate (NO3), Nitrite (NO2), CO3, SO4 are electron acceptors. Inorganic compounds as electron acceptors.
Term
Electron Carriers
Definition
NAD+, NADP+, FAD+. Produce ATP Facultative anaerobes (enteric bacteria)
Term
Fermentation
Definition
Anaerobic process. ) No O2 required
b) inefficient energy production
c) useful products, ex: wine, beer, vinegar, yogurt, etc
Term
Anabolism” and “catabolism” relationship to ATP?
Definition
Catabolism: produces ATP
Anabolism: ATP consumes
Term
What are the different types of media?
Definition
Liquid Media- broth.
Solid Media- Agar.
Selective Media- promotes growth of certain bacteria, inhibits others.
Enrichment Media- helps non-special bacteria gow.
Differential media- differentiates between two types of bacteria on same culture plate.
Term
Bacterial Growth Curve
Definition
Generation time. 1. lag phase. 2. log phase. 3. stationary phase. 3. death or decline phase.
Term
Parasitism
Definition
Organisms live on or within another living organisms. Parasite benefits at the cost of the host. only small number cause disease.
Term
Commensialism
Definition
Organsims- host- no disease. Organsim benefits, host does not. Potential pathogens- staphylococcus- mastitis.
Term
Opportunistic Pathogen
Definition
generally commensal but under stress may cause disease. E-coli: urinary tract infection.
Term
Obligate Pathogen
Definition
almost always cause disease. Ex. Brucella abortus. Mycobacterium paratuberculosis.
Term
Pathogenicity
Definition
capacity of an organism to produce disease.
Term
Virulence
Definition
Degree of pathogenicity
Term
Exotoxins
Definition
excreted proteins. formalin treated- toxoids (inactivated). Protein in nautre. Vaccine effective. Highly toxic. Gram (+) Bacteria.
Term
Endotoxins
Definition
Produced by Gram negative bacteria. Part of cell wall (not excreted) Lipopolysaccharide in nature (lipid A). Vaccine not effective. Poor antigens. Causes fever, shock and tissue inflammation.
Term
Carrier
Definition
State of an animal
Term
Incidence
Definition
New cases at a given point of time
Term
Prevalence
Definition
all cases at given time taken into account.
Term
Latent or inapparent infections
Definition
EX. Brucella
Term
Primary Agent of Disease
Definition
Organism that initiates disease. EX brucella abortis.
Term
Secondary invader
Definition
Follows primary agent. Could not have killed without primary agent. EX. Pasteurella mulocida-pneumonia.
Term
Entry by Preferred Route
Definition
Respiratory Tract, GI tract, Urogenital Tract, Conjunctiva.
Term
Adherence
Definition
Fimbriae/capsules
Term
Different types of Damage to Host
Definition
Direct (Invasion) Localized abscess/ulcer. Production of enzymes (hemolysin, leukocidin, collagenase, streptokinase, etc)
Term
What are major portals of entry of different microorganisms?
Definition
mucous membranes of: Respiratory tract, Digestive tract, Urogenital tract, Conjunctiva

2. broken skin

3.parenteral route by vector bites or by accidental puncture wounds
Term
Various structures and factors that enhance microbial pathogenicity
Definition
a)capsule
b)extracellular enzymes
c)adherence colonization by fimbriae (adhesions), Pili, capsules
Term
Koch's Postulates
Definition
1. Organisms must be regularly isolated from disease. 2. Organisms must be isolated in a pure culture. 3. Such culture should produce typical disease in susceptible animals. 4. Same organisms must be isolated from these animals.
Term
Koch’s postulates: What does it establish?
Definition
it proves conclusively that microorganisms causal role in disease.
Term
Defenses of Host: Non-Specific
Definition
1. Phagocytic cells (neutrophils, macrophages). 2. Complement system. 3. Interferon
Term
Defenses of Host: Specific
Definition
1. B-lymphocytes produce antibody.
2. T-lymphocytes: cytotoxic T-cells: 1. recognize hidden intracellular infected organism within cells. 2. Kills them and kills cancer cells.
Term
Streptococci Principle Characteristics
Definition
Gram(+). Nonmotile. Nonsporing cocci. Occurs in pairs, single or chains. Facultative anaerobic, aerobic. CATALASE (NEGATIVE), OXIDASE (NEGATIVE). Lactose Fermenting.
Term
What is the basis of Lancefield classification of streptococci?
Definition
Based on Component C (polysaccharide in cell wall) Done by ring Precipitation Test. 30 min- tube.
Term
Hemolysis type of on Blood Agar
Definition
Beta- Complete lysis.
Alpha- Greenish zone around colony.
Gamma- Non hemolytic.
Term
What is the basis of Lancefield classification of streptococci?
Definition
Based on Component C (polysaccharide in cell wall) Done by ring Precipitation Test. 30 min- tube.
Term
What are the 3 Genera of Streptococci
Definition
1. Streptococcus. 2. Enterococcus- Opportunistic Pathogen, bile salt resistant, grow on McConkey Agar. 3. Peptostreptococcus- anaerobe,
Term
Mode of Transportation for Streptococci
Definition
1. Endogenous 2. Exogenous- inhalation, ingestion, aerosol, direct contact, fomites.
Term
Streptococcus pyogenes
Definition
sore throat
– scarlet fever, flesh eating necrotizing fascitis in humans
Term
Streptococcus agalactae
Definition
highly contagious mastitis
Term
Strep porcinus
Definition
jowl abscess
Term
Streptococcus suis
Definition
meningitis, arthritis
Term
Enterococcus faecalis
Definition
urinary infections, endocarditis
Term
Streptococcus dysgalactiae, Streptococcus uberis
Definition
mastitis
Term
Streptococcus equi
Definition
strangles in horses
Term
Staphylococcus aureus
Definition
– bovine (Botryomycosis) mastitis, food poisoning, toxic
shock syndrome
Term
Staphylococcus hyicus
Definition
greasy pig disease syndrome
Term
Strangles
Definition
Highly Contagious, fever, abscess of cervical and submandibular lymph nodes, upper resp. infection. Lymph nodes may rupture, depression, anorexia. Transmission: inhalation, contact with discharge. Gutteral Pouch (carriers).
Term
Staphylococci Principal Characteristics
Definition
Gram(+) cocci. Pairs, chains, clusters. Aerobic-f acultative anaerobe. Catalase (+) Oxidase (-). Non-motile, non spoirng, lactose fermenter.
Term
Habitat of Staph Aureus
Definition
Commensal skin and mucous membrane of upper respiratory and GI tract.
Term
Staph. Aureus: Time, Signs, Foods
Definition
1-6 hours. Vomiting, nausea, diarrhea. Milk products, cream, ground meat.
Term
Salmonella: Time, Signs, Food
Definition
24-48 hours. Nausea, vomiting, diarrhea. Improperly cooked food/meat, water.
Term
Hemolysins of Staphlococci
Definition
alpha hemolysin: rabbit erythrocytes: inner clear zone.
Beta Hemolysin: sphingomyelinase C.
Term
Possible Factors synthesized and excreted from Staphlycocci
Definition
1. Coagulase (Plasma clotting- related with pathogenicity) 2. Enterotoxins 3. Hemolysins 4. Lipase 5. Staphylokinase (degrades fibrin) 6. Leukocidin 7. Exfoliative toxin 8. Hyleuronidase 9. Penicillinase (B-lactamase) 10. Protein A
Term
Pathogenesis of Staphylococci
Definition
Pyogenic response, Capsule, Toxins, Generally immunocompromised host defense or stress, Abscess, Septicemia.
Term
Pathogenicity of Staphylococci
Definition
Botryomycosis (chronic granulomatous lesion of udder of mare, cow, sow) Pyoderma of dogs, Bovine mastitis, Otitis, Arthritis, Urinary infections, Enterocolitis, Impedigo.
Term
Staph. Intermedius- Hemolysis, characteristics and types.
Definition
B-hemolytic, Gray non-pigmented. Two types: Poly P- dog strains. Poly C- region strains.
Term
Staph. Hyicus
Definition
Swine pathogen "Greasy pig disease" or exudative dermatitis.
Term
Micrococci
Definition
Non-pathogenic, usually pigmented, Needs to be differentiated from S. aureus.
Term
Corynbacteria principal characteristics
Definition
Gram(+), Small rods, Pleomorphic (Chinese letter arrangement), non-motile, non-sporing, facultative anaerobic, Catalase(+), Lactose fermentor.
Term
Species of Corynebacteria
Definition
C. diphtheriae (human diphtheria), Corynebacterium renale (cystitis, urethritis, polynephritis in cows, kidney abscess in swine). C. pylosum and C. cistitidis.
Term
Habitat and Mode of transmission of Corynebacteria
Definition
Male and female genital tract. Mode of transmission is venereal, contaminated urine.
Term
Mode of infection of Corynebacterium pseudotuberculosis
Definition
Abraded skin or injury and inhalation
Term
Pathogenicity of Corynbacterium pseudotuberculosis
Definition
Sheep and goat- caseous lymphadenitis- green pus.
Cattle, horses and mules- Ulcerative lymphangitis.
Term
Identification of Corynebacterium pseudotuberculosis
Definition
Nitrate reduction. Cattle and horses (positive). Sheep and goats (negative)
Term
Rhodococcus equi Principal Characteristics
Definition
Gram(+), pleomorphic rods, non-lactose fermenter, catalase (+), Urease (+_, Colonies -pink pigment. Mucoid.
Term
Habitat and Mode of infection of Rhodococcus equi
Definition
Habitat- horse feces and soil.
Mode of infection (young foals common) inhalation or direct contact. Older horses: Carriers- transmit infections to foals.
Term
Pathogenicity and pathogenesis of Rhodococcus equi
Definition
Supportive bronchopneumonia (foals) submandibular and cervical lymph node involvement. abortion in mares.
Term
Listeria Principal Characteristics
Definition
Gram(+), small rods, motile at room temperature, catalase (+), oxidase(+).
Term
What is the Causative agent for Listeria
Definition
Listeria monocytogenes- beta hemolytic, L. ivanovii (pathogenic)
Term
Habitat and Mode of infection of Listeria
Definition
Silage (when pH rises above 5.5- bacteria multiplies in silage) Mode of infection- Neural form: mucous membranes of eyes, nose and throat. Visceral form: ingestion.
Term
What is that Pathogenicity and Pathogenesis of Listeria
Definition
1. Neural form (circling disease: cattle sheep and ruminants. Higher incidence in winter and early spring on feedlots. CNS involvement- unilateral ataxia, meningitis.
2. Visceral form: abortion in cow, mares, sows and humans, chicken and turkeys- septicemia.
Term
peScimen of Listeria
Definition
1. Neural form: brain- pons and medulla.
2. Visceral form: abortion- fetus and fetal membrane.
Term
Differential Diagnosis of L. monocytogenes and Erysipelothrix rhusiopathiae
Definition
L. monocytogenes- Catalase (+) Motility (+) Culture bio (lethal)
Erysipelothrix rhusiopathiae- catalase (-) motility (-) Culture bio (non)
Term
Erysipelothrix Principal Characteristics
Definition
Gram (+), small rods, non-sporing, Catalase (-)
Term
Considerations for optimal bacterial growth
Definition
a. appropriate conditions of moisture
b. pH-optimal is neutral 7.2
c. Temperature- optimal is 37C or 98.6F
d. Osmotic pressure
e. Atmosphere
f. Nutrients
Term
Bacteria increase in numbers througha process known as:
Definition
Binary fission
Term
What is Generation time
Definition
It is the amount of time that is required for 1 bacterium to yield 2 daughter cells. Genetics and nutrition influence this process.
Term
Bacterial Growth Graph
Definition
Lag- aquire essential constituents prior to division.
Exponential- binary fission is taking place.
Stationary- essential nutrients start to deplete, replication slows.
Decline- Death of bacteria
Term
What does "Aerobe" mean?
Definition
Bacteria that requires oxygen.
Term
What does Microaerophilic mean
Definition
Bacteria that requires reduced oxygen levels for growth
Term
What does Obligate Anaerobes mean?
Definition
Bacteria that is unable to grow in oxygen
Term
What is facultative anaerobes
Definition
Grow both in presence or lack of oxygen
Term
What is capnophils?
Definition
bacteria that is aerobic, also requires carbon dioxide.
Term
What are the different FORMS of Media
Definition
Liquid, Solid, Semi-solid
Term
Liquid media
Definition
Broth is used for growing large amounts of bacteria. Liquid cultures are used in inoculating biochemical tests as well.
Term
Solid Media- reasons for concentration.
Definition
Made from agar, which is used as a solidifying agent. Agar is an agent extracted from algae and usually added to broth at a concentration of 1.5% to make a solid agar plate. Two reasons for this concentration:
1. Wet enough to support bacterial growth.
2. Dry enough to keep colonies separate.
Term
Semi-solid media
Definition
Type of liquid medium where agar is only added at a concentration of 0.5%-jello before it is refrigerated type consistency. Media used to test specific bacterias ability to utilize sugars.
Term
Types of Media
Definition
Basic, Differential, Selective.
Term
Basic type of Agar
Definition
Media will support aerobic growth of gram(-) and gram(+) bacteria. ex. Sheep blood agar
Term
Differential type of agar
Definition
media which display a visible difference between colony types. Usually by color. Ex. Eosin methylene blue
Term
Selective type of Media
Definition
Media in which specific inhibitors are added to prevent the growth of organisms you do not wish to grow. ex. Eosin methylene blue or phenylethanol agar.
Term
Methods to achieve selective media:
Definition
pH adjustment (high or low can be inhibitory to bacterial growth)
Addition of antibiotics (certain drugs will affect bacterial growth)
Addition of growth inhibitors (Such as eosin dye, methylene blue and phenylethanol)
Term
Nutrition Agar
Definition
Provides essential nutrients for growth of non-fastidious bacteria, not suitable for fastidious organisms. Suitable for demonstrating colonial morphology and pigmentation. Solid/Basic.
Term
Sheep Blood Agar
Definition
Made from 5% defibrinated Sheep blood. Media which will support growth of both gram (-) and gram (+) organsims. Support and enhance growth of organsims, will determine patterns of hemolysis.
Term
Interpretation of Hemolysis looking at the Bottom of Agar
Definition
Alpha- colonies surrounded bya zone of intact but greenish RBCs.
Beta- colonies surrounded by a clear zone with no intact RBC's.
Gamma- colonies do not change appearance of the RBCs (NO hemolysis)
Term
Chocolate Agar
Definition
Heeat treated blood agar, red blood cells are lysed which releases 2 factors. X and V factors. Solid/ selective and Basic. Specific for haemofelis species.
Term
MacConkey Agar
Definition
Contains bile and lactose which is useful in isolation of enterobacteria and other gram (-) organisms. Will differentiate between lactose fermentors and non-lactose fermenters. Solid/slective and differential.
Term
Interpretation of Colors on MacConkey Agar
Definition
Colonies of lactose fermenters and surrounding medium are pink.
Non-lactose fermenters impact a yellow color to the medium.
Term
Eosin Methylene Blue Agar
Definition
Made with eosin dye and methylene blue. contains lactose and sucrose. will not grow gram (+) organsims. Isolation of gram (-) bacteria from contaminated sample. Differentiation of lactose fermenting from non-lactose ferming microorganisms.
Term
Interpretation of growth colors on EMB
Definition
Blue/black colonies (strong lactose/sucrose fermentation)= STRONG LACTOSE FERMENTER SLF.
Dark pink/dark center (lactose ferementer LF)
Pink mucoid colonies (Weak lactose fermenter- WLF)
Amber/colorless colonies- No fermentation of lactose/sucrose (Non-lactose fermenter- NLF)
Term
Colonial Description On EMB plate
Definition
Color (Pink, purple, black, reen metallic sheen, translucent, amber, pink/purple) Carbohydrate fermentation (SLF, LF< WLF, NLF) Size, Texture, Border of the colony
Term
KOH test
Definition
Reagent- Potassium hydroxide. Positive= stringy= Gram (-)....Negative=not stringy= Gram(+)
Term
Opportunistic Pathogen
Definition
An infectious microorganism that is normally a commensal or does not harm its host but can cause disease when the host’s resistance is low.
Term
Lactose Fermenters are found on what plate
Definition
EMB
Term
Streptococci-
Gram Reaction.
Group contains
Shape
Catalase
Definition
Opportunistic pathogen
Group contains: Streptococcus, Enterococcus (aerobic) Petptostreptococcus (anaerobic)
Gram (+)
Cocci
Catalase -
Term
What are the types of differentiation tests that ID Streptococcus spp. from Enerococcus spp.
Definition
6.5% NaCl and PYR Test (pyrrolidonyl Arylamidase)
Term
6.5% NaCl test- What does it do and what do the results mean?
Definition
Will determine the salt tolerance of an organism. If salt can be tolerated the organism will grow and break down dextrose to produce an acidic pH.
Positive= Growth of organism. Color= yellow. Enterococcus spp.
Negative= No growth of organism. Color= Purple. Streptococcus spp.
Term
Positive 6.5% NaCl test
Definition
Growth of organsim.
Color= Yellow
Enterococcus spp.
Term
Negative 6.5% NaCl test
Definition
No growth of organism
Color= purple
Streptococcus spp.
Term
PYR test- what does it do and what do the results mean?
Definition
The presence of amino peptidase enzyme results in a pink color with indicator.
Positive= Cherry pink/red= Enterococcus spp.
Negative= No color change= Streptococcus spp.
Term
Susceptibility test for Streptococcuswith Vancomycin 30mcg disk
Definition
Vancomycin is an antimicrobial agent. Test is used to determine whether the specific bacteria that you are testing is Sensitive to this specific antibiotic.
Term
Interpretation of Susceptibility Test- Vancomycin 30 mcg disk
Definition
Sensitive (s)= zone of inhibition around the organism. Enterococcus spp. and Streptococcus spp. will be sensitive to 30 mcg. Vancomycin disk.
Resistant (r)= No zone of inhibition around the organism.
Term
What is the CAMP test? What is it used to identify?
Definition
Determine the ability of an organism to produce an elaborate CAMP factor protein which acts synergistically with Staphylococcus aureus.
Used to identify Streptococcus agalactiae
Term
Interpretation of CAMP test
Definition
Positive= Production of an arrowhead zone of complete hemolysis located at the juncture of Staph and Strep. Identifies= streptococcus agalactiae.
Negative= No arrowhead zone of hemolysis. NOT streptococus agalactiae.
Term
Catalase Test- What is it and what does it mean?
Definition
An enzyme produced by anaerobes and facultative anaerobes, that causes the breakdown of hydrogen peroxide to oxygen and water. A positive oxidase test indicates the presence of cytochrome oxidase C in the bacterial cell. DO NO STAB AGAR TO COOL.
Interpretation: Postive= bubbling
Negative= No bubbling
Term
Example of Catalase test
Definition
Streptococci spp= Negative
Paseurella spp. = Positive.
Term
KOH test
Definition
Potassium hydroxide.
Used as a back-up to gram staining procedure. Gram(-) cell wall is destroyed when KOH is introduced and results in the liberation of viscid DNA.
Term
Oxidase Test- what it is and what is the interpretation
Definition
Determines the presence of Cytochrome Oxidase enzymes. Watch for color change.
Positive= A dark purple color will be produced within 10-30 seconds. Micrococcus spp. will yeild positive results.
Negative: The organism will not turn purple before 30 seconds. Staphylococcus spp. will yield positive results.
Term
What are some factors that cause G(+) bacteria to appear G(-)?
Definition
1. Culture Age: As bacteria ages they lose their ability to retain Primary Stain.
2. Over-Decolorization: Crystal Violet may wash off with too much alcohol.
3. Over Rinsing: too much time spent rinsing with water can wash cells off the primary stain.
Term
Factors that cause G(-) bacteria to appear G(+)
Definition
Over-crowding: Too much bacteria on microscope slide.
Term
Primary Stain
Definition
Crystal Violet- Imparts blue color to all cells
Term
Grams Iodine
Definition
Improves bonding between stain and specimen
Term
95% Ethyl Alcohol
Definition
Removes color from G(-) organisms, G(+) will remain blue
Term
Safranin
Definition
G(-) bacteria turn pink, G(+) remain blue.
Term
Staphylococci
Group
Gram Stain
Catalase
Definition
Opportunistic- most cause skin issues
Gropu contains the genera Staphylococcus spp. and Micrococcus spp.
Gram (+) cocci
Catalase (+)
Term
Differentiation tests for Staphylococci
Definition
Susceptibility Test- Bacitracin and Furazolidone
Oxidase Test
Accu-Staph
API-Staph
Term
Susceptibility Test for Staphylococci - Bacitracin 0.04 unites disk and Furazolidone 100 mcg disk
Definition
Sensitive (S): Zone of inhibition around the organism.
MICROCOCCUS SPP. sensitive to BACITRACIN
STAPHYLOCOCCUS SPP. sensitive to FURAZOLIDONE.
Resistant (R): No Zone of inhibition around the organism.
MICROCOCCUS spp. resistant to Furazolidone
STAPHYLOCOCCUS spp. resistant to BACITRACIN
Term
ACCU-STAPH
Definition
Latex Slide Agglutination. Positive= Red clumps of agglutination- staphylococcus aureus.
Negative= no agglutination- not staphylococcus aureus.
Term
Corynebacterium pseudotuberculosis
Definition
Causes lymphadentitis, infection spreads via the lymph nodes.
Colonies are more easily observed in 48 hours.
Bacilli- Chinese letter arrangement- palisades.
Small, dry, crumbly small zone of beta hemolysis.
GRAM + CATALASE +
Term
Rhodococcus equi
Definition
Formerly in the Corynebacterium genus.
Causes pneumonia in foals.GRAM + CATALASE +
Colonies are more easily observed in 48 hours
Small rods, gamma hemolytic.
Term
Listeria monocytogenes
Definition
Causes meningitis, encephalitis, uterine infections with abortions, still births, etc. GRAM + CATALASE +
Term
What is the Cold Enrichment Procedure for detection of Listeriosis?
Definition
OLD METHOD- Organisms are intracellular.
1. Grind brain up in enrichment broth.
2. Store in fridge for 12 weeks.
3. Reculture each week for 12 weeks.
Term
Bacillus spp.
Definition
Causes multiple issues including abortions, mastitis, food poisoning. Beta or Gamma hemolytic. GRAM + CATALASE +
Term
Bacillus anthracis-- how is it acquired?
Definition
Very important pathogen. ANTHRAX. Death will result if not treated.
Acquired by:
1. Inhalation
2. Ingestion
3. Wounds
4. Simple scratch.
GRAM + CATALASE +
Term
Dermatophilus congolensis
Definition
Gram + Bacilli, Catalase -
Causes skin infections forming crusts.
Direct Examination:
1. Scabs/hair are softened with DH20 in CO2 for 20 minutes.
A scum will come to the surface of the water
Plate the culture material.
Remove the softened, scabs and mash between two slides and air dry
Giemsa stain. Examine for morphology. "Train Track" Morphology- double row of coccoid spores called zoospores.
Term
What does TSI do?
Definition
Triple Sugar Iron- will detect the fermentation and gas production from glucose, sucrose and lactose. Will also detect H2S production. Sucrose and Lactose in the slant. Glucose in the Butt. Na thiosulphate and Ferrous sulfate detects H2S production.
Acid (A) yellow
Alkaline (K) red
Term
Interpretation of TSI- Slant
Definition
Red=K- no utilization of sucrose and lactose
Yellow= A- Utilization of sucrose and lactose.
Term
TSI interpretation- Butt
Definition
Red= K- No utilization of glucose
Yellow= A- Utilization of glucose
Term
TSI interpretation- Gas
Definition
Bubbles/ Splitting of Media= Gas production
No Bubbles/ Splitting= No Gas Production
Term
TSI interpretation- H2S
Definition
Black Precipitant= H2S production
No Black Precipitant= No H2S production
Term
TSI Total Interpretation
Definition
Slant/Butt/Gas/H2S
EX. A/A/-/+
Term
McFarland Standard
Definition
0.5=1.5
1=3
2=6
3=9
4=12
x 10^8/mL
Term
Indole Test
Definition
Positive – a pink color

2. Negative – no pink color/ remains buff-yellow
Term
differential characteristics between B. anthracis and B. cereus.
Definition
B. cereus- motility, capsule, penicillin susceptiblity, aerobic/facultative anaerobic. Clostridium- anaerobic, endospores (anthrax).
Term
Why is necropsy not recommended for an animal dying of anthrax?
Definition
Because of inhalation mode of transmission. Spores can be released when opened.
Term
Components of anthrax toxin and their specific role in pathogenesis of disease.
Definition
-Exotoxin
-Capsule
-All virulent straisn- capsulated an produce toxin.
Peracute- Septicemia (bleeding from nose and mouth)
Acute (cattle, sheep, horses)
Chronic- cutaneous form
Cuatneous- 90% humans Lethal if pulmonary.
Term
f) What is “string of pearl” test and what specific bacteriophage is used in typing of B. anthracis?
Definition
Penicillin
-Gamma phase lysis- positive
-F.A> test.
-Animal inoculation- guinea pig.
PCR test.
Term
Environmental resistance of bacteria and its spores
Definition
Endospores- highly resistant
drying presence in soil, freezing- several years.
boiling destroys bacteria in 10 minutes.
10-20% formaldehyde or 2% gluaraldehyde- 10 minutes.
autoclaving- 15 lbs pressure for 15 minutes!!!
Term
How would you properly dispose an animal that dies of anthrax?
Definition
Animal Carcasses- buried 6 feet in the ground with lime which will degrade animal and kill bacteria.
Term
Which vaccine is currently used for vaccination of cattle?
Definition
Avirulent spore vaccine (stern's non-capsulated strain)
Term
What is the typical colony characteristic of most of corynebacterial colonies on blood agar plates?
Definition
Blood agar- sticky colonies: Coryne ID.
Term
Difference on EMB agar of E. coli and Salmonella
Definition
E. coli- lactose fermenter- metallic sheen greenish/blue colonies.
Salmonella does not ferment lactose= clear colonies.
Term
Serotyping of Enterobacteria
Definition
O= Antigen- cell wall
H= Antigen- flagellar (E.coli)
K= kapsular
F= fimbrial
P= Pili
Term
Escherichia coli
Definition
Causes wide variety of infections in many animals. Some strains pathogentic
Ferments lactose.
EMB agar= metallic sheen
McConkey agar= pink
Serotyping- using O, K and H antigen which indicates virulence
Term
Fimbriae of E. Coli
Definition
very important for attachment and colonization of pathogenic strains.
Term
Enterotoxigenic E.Coli strains
Definition
diarrhea in young claves, pigs, lambs and post weaning diarrhea in pigs.
Produce enterotxoins
LT= heat Labile- enteritis
ST= Reduce absorption
Cary adhesions: F4 (K88) F5 (K99) F6 (987P) toxins.
Term
Enteropattogenic E. coli strain
Definition
diarrhea pigs, lambs, pup. Produce intiminan adhesion.
Attaching Effacing
Destruction of microvilli: maldigestion/malabsorption.
Term
Verotoxigenic E. Coli
Definition
Hemolytic urimic syndrome.
SLT= shiga like toxin.
Term
Necrotoxigenic E. Coli
Definition
Hemorrhagic colitis in cattle, enteritis in piglets and calves, diarrhea in rabbits, dysentery in horses. Bind Enterocytes- produce CNF1 and CNF2 CNF= Cytotoxic Necrotizing factore.
Term
Salmonella
Definition
Gram - rods
Nonlactose fermenter
Most are motile
More than 2400 serotypes
Two species:
1. S. bongori
2. S. enterica
All animal and human pathogens.
Term
Pathogenicity
Definition
Invasive intracellular parasite
Attach, resist phagocytosis and compliment mediated lysis
Virulence factors include Endotoxins which also damage intestinal epithelial cells.
Term
Clinical infections of Salmonella
Definition
Localize in mucosa of ileum, cecum and colon, mesenteric lymph nodes.
Term
ENteric Salmonellosis
Definition
all ages, all species.
Term
Carrier state of salmonella
Definition
Enteritis. Adults can be source of infection of young animals
Term
Public Health Significance of Salmonella
Definition
Reservoir and sources of infection: Domestic animals, wild animals, humans all develop carrier state.
Other sources:
feces of humans and animals, eggs, egg products, milk and meat products.
Term
Transmission of Salmonella
Definition
Ingestion (epidemics tracable to food products and contaminated water, carrier food handlers, equipment and utensils.
Term
3 species of Yersinia
Definition
1. Y. pestis
2. Y. pseudotuberculosis
3. Y. enterocolitica
Term
Yersinia pestis
Definition
Causes plague in rodents and humans. Humans are accidential hosts (flea transmits) found in man animal species.
Term
Escherichia: Immunity, Bacterins, Fimbriae
Definition
Immunity: Antigenically heterogeneous
Bacterins: limited usefulness
Fimbriae: pilus vaccine useful because it prevents attachment and colonization.
Term
Salmonellosis: Immunity, Bacterins, S. typhimurium
Definition
Immunity- cell mediated mainly
Bacterins: limited value
S. typhimurium: attenuated live vaccine used in cattle in england.
Term
Pathogenesis of Y. pestis
Definition
Exotoxin found in all virulent strains.
2 forms:
1. bubonic form- lymph nodes leads to
2. pneumonia form- highly contagious and if not treated- fatal.
Term
Mechanism of transmission of sylvatic/or jungle plague to humans?
Definition
Sylvatic plague-fleas-rodents-fleas-humans-sylvatic plague
occurs in several states in sparsely populated rural areas.
Term
Two major differences between Y. pestis and Y. enterocolitica
Definition
Y. enterocolitica does not affect animals and grows slow.
Term
Y. pseudotuberculosis
Definition
lymphatinitis, causes orchitis in rams.
involves mesenteric lymph node that spreads to liver and spleen.
Term
y. entercolitica
Definition
does not affect animals but if they carry it on their meat will affect humans. Mesenteric adentitis and other infections.
Term
Cold enrichment in Y. enterocolitica.
Definition
as in listeria monocytogenes.
Term
Cross reactions between Brucella and Y. enterocolitica serologic reaction during Brucellosis testing.
Definition
Y. enterocolitica shares antigen with Brucella sp/ so may give FALSE BRUCELLA AGGLUTINaTION REACTION
Term
Chemotherapy- definition and requirement
Definition
Definition: Treatment of infectious diseases by drugs which are lethal or inhibitory to infectious agents.
Requirement- Should be selectively toxic to infectious agent but not to host or its cells.
Term
Antibiotics- definition and EXAMPLES
Definition
Antimicrobial substance produced by living organisms.
Ex:
Fungus Penicillium notatum- penicillin
Fungus Cephalosporium- Cephaolosporins
Bacteria Streptomyces- Streptomycin
Bacteria Bacillus polymyxa- polymyxin
Term
Bacterial drugs and examples
Definition
rapid lethal action- drugs that will kill bacteria.
Ex. Penicillin, streptomycin, cephalosporins, polymyxin.
Term
Bacteriostatic drugs
Definition
inhibitory to the growth of organisms.
EX.
Tetracyclines, sulfonamides, chloramphenicol.
MOST drugs generally have both kind of activity.
Term
Antimicrobial susceptibility test
Definition
two types:
disc susceptibility test (routinely done in vet diagnostic lab)
2. Tube susceptibility test (used at BVC)
Term
Disc Susceptibility Test
Definition
Uniform inoculation of plate with bacteria on Media. Measure zone size. more than certain size- sensitive. Less than certain size- resistant.
Term
Tube susceptibility test
Definition
determines the minimum inhibitory concentration (MIC). Those tubes without evidence of growth (turbidity) are plated out to determine the minimum bactericidial concentration (MBC)
Inoculate same number of bacteria.
Term
Mechanisms of drug resistance (the four points listed with examples)
Definition
a. Adoption to an alternate pathway EX. resistance to sulfonamides adoption of using folic acid from outside source.
b. Production of an enzyme that destroys antibiotic. EX. Penicillinase (b-lactamase) by Staph aureus, pseudomonas
c. Change in permeability of cell membrane. Ex: tetracycline to polymyxins.
d. Altered target of drug: erythomycin resistant organsims ahve a modified protein on ribosomes.
Term
Adoption to an alternate pathway EXAMPLE
Definition
resistance to sulfonamides adoption of using folic acid from outside source.
Term
Production of an enzyme that destroys antibiotic. EXAMPLE
Definition
Penicillinase (b-lactamase) by Staph aureus, pseudomonas
Term
Change in permeability of cell membrane. EXAMPLE
Definition
tetracycline to polymyxins.
Term
Altered target of drug EXAMPLE
Definition
erythomycin resistant organisms have a modified protein on ribosomes.
Term
Superinfection
Definition
by excessive antibiotic use of normal flora are killed, it may lead to super infection by fungi or yeast. ex.Canida, pseudomonas infection when normal bacteria are killed by antibiotic
Term
Infectious drug resistance EXAMPLE
Definition
by transfer of multiple drug resistant plasmids from one strain to another closely related strain or bacteria (by conjugation mainly)
Ex.
E. coli to E. coli
Salmonella to Salmonella
E. Coli - Salmonella
Term
How could antibiotics in animal feed lead to selection of drug resistant bacteria?
Definition
Use of sublethal or subinhibitory levels
Term
Synergistic
Definition
penicillin and streptomycin= both bactericial
Term
antagonistic
Definition
Penicillin(bactericial) + Tetracycline (bacteriostatic)
Term
How to limit Drug Resistance
Definition
1. No prophylactic use in feed.
2. Complete Course.
3. Prescription use only.
Term
Koch's Postulates
Definition
1. Organims must be regularly isolated from disease
2. Organisms must be isolated in a pure culture.
3. Such culture should produce typical disease in susceptible animals
4. Same organims much be isolated from these animals.
Term
Oxidative Phosphorylation
Definition
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
P+ADP= ATP- source of energy
Term
Oxygen Toxicity
Definition
enzyme to neuralize this:
a. superoxide dismutase
b. catalase
c. peroxidase.
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