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Microbiology Hell
Microbiology
85
Microbiology
Undergraduate 4
04/19/2016

Additional Microbiology Flashcards

 


 

Cards

Term

 

 

Streptococcal Pharyngitis (Caustive Agent) 
Definition

 

- Streptococcus Pyogenes

Gram-positive

β hemolytic

Term

 

 

Streptococcal Pharyngitis

(Symptoms)

Definition

Symptoms: 

Sore, red throat, with pus and tiny hemorrhages, enlargement and tenderness of lymph nodes in the neck; less frequently, abscess formation involving tonsils; occasionally, rheumatic fever and glomerulonephritis as sequels.

Term
 


Streptococcal Pharyngitis

(Pathogenesis)

Definition
 
–Causes a wide variety of illnesses (due to toxins and exoenzymes)

 

–Complications of infection can occur during acute illness
Term

 

 

 

 

Streptococcal Pharyngitis

(Epidemiology)

Definition
 
–Spread readily by respiratory droplets
•Especially in range of 2 to 5 feet
–Infect only humans under natural conditions
–Nasal organism spreads more effectively than pharyngeal carriers
–Peak incidence occurs in winter or spring


•Highest in grade school children

Term



Streptococcal Pharyngitis

(Prevention)

Definition
 
–No vaccine available
–Adequate ventilation
–Avoid crowds

 

–Sore throats in presence of fever should be cultured for prompt treatment
Term

 

 

Streptococcal Pharyngitis

(Treatment)

Definition
–Confirmed strep throat treated with 10 days of antibiotics
•Penicillin or erythromycin are drugs of choice

 

–Eliminates organisms in 90% of cases
Term



Common Colds

(Causative Agent)

Definition
 
–30% to 50% caused by rhinovirus
•Non-enveloped

 

•Single-stranded RNA genome
Term



Common Cold

(Pathogenesis)

Definition
 
–Virus attaches to specific receptors on respiratory epithelial cells and multiplies in cells
•Large number of viruses released from infected cells
–Injured cells cause inflammation which stimulates profuse nasal secretion, sneezing and tissue swelling
–Infection is halted by inflammatory response, interferon release and immune response

 

•Infection can extend to ears, sinuses and lower respiratory tract before stopping
Term

 

 

 Common Cold 

(Epidemiology)

Definition
 
–Humans are only source for virus
–Close contact with infected person or secretions usually necessary for transmission
•High concentrations are found in nasal secretions during first 2 or 3 days of it

Young children transmit it easily

Term

 

Common Cold 

(Symptom)

Definition

 

 

Scratchy throat, nasal discharge, malaise, headache, cough

Term

 

Common Cold

(Prevention)

Definition
 
–No vaccine
•Too many different types of rhinovirus

 

- directed at
•Hand washing
•Keeping hands away from face

 

•Avoiding crowds during times when colds are prevalent

-Treatment
–Antibiotic therapy is ineffectual
–Certain antiviral medications show promise
•Must be taken at first onset of symptoms
–Treatment with over-the-counter medications may prolong duration due to inhibition of inflammation
Term



Pinkeye, Earache and
Sinus Infections

(Causative Agent)

Definition
 
Haemophilus influenza
•Gram-negative bacillus
Streptococcus pneumoniae
•Gram-positive diplococci
–Otitis media and sinusitis
Mycoplasma pneumoniae
Streptococcus pyogenes
Staphylococcus aureus

 

–One-third of cases of otitis media have viral etiology
Term

 

 

 

Pinkeye

(Pathogenesis)

Definition
 
 
–Most likely from airborne respiratory droplets

 

–Resist destruction by lysozyme
Term

 

 

Earache

(Pathogenesis)

Definition
 
Often developing at the time of conjunctivitis diagnosis
•Begins with infection of nasal chamber and nasopharynx

 

Term

 

 

Sinus Infection

(Pathogenesis)

((

Definition
 
 
•Begins with infection of nasopharynx and spreads upwards

 

•Pathogenesis mechanism much like that of otitis media
Term



Pinkeye, Earache and
Sinus Infections

(Epidemiology)

Definition
 
–Carrier rates of H. influenza  and

   S. pneumoniae can reach 80%

–Epidemics of pinkeye common among school children
•Generally in crowded environments
–Otitis media very common in early childhood
•Older children develop immunity to H. influenza
–Less common cause  of earache after age five
–Sinusitis occurs in adults and older children

 

•Generally due to more developed sinuses
Term

 

 

Pinkeye

(Prevention and Treatment)

Definition
 
•Prevention is directed towards
–Removal of infected individuals from school or day care
–Hand washing
–Avoid rubbing or touching eyes
–Avoid sharing towels

Treatment is achieved through eyedrops or ointments containing antibacterial medications

Term

 

 

Earache

(Prevention and Treatment)

Definition
 
•Prevention is directed towards
–Administration of influenza vaccine to infants in day care facilities during “flu” season
 
•Treatment includes
–Antibiotic therapy

 

»Amoxicillin
Term

 

 

Sinus Infection

(Treatment and Prevention)

Definition
 
•There are no proven preventative measures 
•Treatment is directed at support care
–Decongestants and antihistamines are generally discouraged

 

»Ineffective and can be harmful
Term

 

 

Pneumonia

(Causative agents)

Definition
 
Streptococcus pnuemoniae
•Gram-positive
•Capsule responsible for virulence
•80 different types of

   S. pneumoniae

Klebsiellapneumoniae
•Gram-negative
•Bacillus
•Encapsulated
Mycoplasma pneumoniae
•Deformed bacterial lacking cell wall

 

•Aerobic
Term

 

 

Pneumonia

(Epidemiology)

Definition
 
–30% of healthy individuals carry encapsulated strain in their throat

 

•Bacterial rarely reach lung due to mucociliary escalator
Term

 

 

Whooping Cough

(Causative Agent)

Definition
 
Bordetella pertussis
•Encapsulated
•Strictly aerobic
•Gram-negative
•Bacillus -> endo spores

 

•Does not survive long periods outside the host
Term

 

 

Whooping Cough

(Pathogenesis)

Definition
 
B. pertussis produces numerous toxic products (A-B toxin)
-B portion attaches to cell surface
-A portion enters cell
»Causes increased mucus formation

 

»Decreases phagocytic killing
Term

 

 

Whooping Cough

(Epidemiology)

Definition

 

  • Spreads via infected respiratory droplets
  • Most infectious during runny nose period
  • Number of organisms decrease with onset of cough
  • Classically disease of infants
  • Often overlooked as a persistent cold
  • Fosters transmission

 

Term



Whooping Cough

(Prevention)

Definition
–Directed at vaccination of infants
•Prevents disease in 70% of individuals
•Pertussis vaccine combined with diphtheria and tetanus toxoids (DPT)

 

–Injections given at 6 weeks, 4, 6 and 18 months
Term

 

 

Whooping Cough

(Treatment)

Definition
 
–Erythromycin is effective at reducing symptoms if given early

 

–Antibiotic usually eliminates bacteria from respiratory secretions
Term

 

 

Whooping Cough

(Symptoms)

Definition

 

Violent coughing, vomiting and possible convulsions

Term

 

 

Tuberculosis

(Causative Agent)

Definition
 
Mycobacterium tuberculosis
•Gram-positive, bacillus
•Acid fast due
•Slow growing
–Generation time 12 hours or more

 

•Resists most prevention methods of control
Term

 

 

Tuberculosis

(Symptoms)

Definition
 
–Chronic illness
–Symptoms include
•Slight fever with night sweats
•Progressive weight loss
•Chronic productive cough

 

–Sputum often blood streaked
Term

 

 

Tuberculosis

(Pathogenesis)

Definition
 
–Usually contracted by inhalation of airborne organisms
–Bacteria are taken up by pulmonary macrophages in the lungs then sent to lymph nodes
–Resists destruction within phagocyte

 

–About 2 weeks post infection intense immune reaction occurs
Term

 

 

Tuberculosis

(Epidemiology)

Definition
 
–Estimated 10 million Americans infected
•Rate highest among non-white, elderly poor people
–Small infecting dose
•ID 10 (inhaled)
–Factors important in transmission

 

•Frequency of coughing, adequacy of ventilation, degree of crowding
Term



Tuberculosis

(Prevention)

Definition
 
–Vaccination widely used in many parts of the world

 

•Vaccine not given in US because it eliminates use of a test as diagnostic tool
Term

 

 

Tuberculosis

(Treatment)

Definition
 
–Antibiotic treatment is given in active cases
•Two or more medications are given together to reduce potential antimicrobial resistance
•Antimicrobials include
–Rifampin and Isoniazid (INH)
•Therapy is prolonged

 

–Lasting at least 6 months
Term

 

 

Influenza

(Causative Agent)

Definition
 
–Influenza A virus
•Single-stranded RNA genome
–Genome divided into 8 segments
•Spiked envelope
–H spike – hemagglutinin
»Aids in attachment
»N spikes – neuraminidase

 

»Aids in viral spread
Term

 

 

Influenza 

(Pathogenesis)

Definition
 
–Acquired through inhalation of infected respiratory secretions
–Infected cells die and slough off
•Destroy mucociliary escalator
–Host immunity quickly controls viral spread

 

–Small number of people die from it
Term

 

 

Influenza 

(Epidemiology)

Definition
–Outbreaks occur in United States every year
•Associated with 10,000 to 40,000 deaths
–Pandemics occur periodically
•Most “famous” pandemic of 1918
–Spanned the globe in 9 months

 

•Pandemics have higher than normal morbidity
Term

 

 

Influenza 

(Prevention and Treatment)

Definition
 
–Vaccine can be 80% to 90% effective
–New vaccine required every year
•Due to antigenic drift
•Antiviral medications are 70% to 90% effective
•Must be taken early

 

•Not a substitute for vaccine
Term

 

 

Rocky Mountain Spotted Fever

(Symptoms)

Definition
 
–Distinguished by initial rash of faint pink spots
•Appears first on palms, wrists, ankles and soles of feet

 

–Rash becomes raised and hemorrhagic, eventually spreads to other parts of the body
Term

 

 

Rocky Mountain Spotted Fever

(Causative Agent)

Definition
 
Rickettsia rickettsii
–Obligate, intracellular bacterium
•Requires host organism for survival
–Gram-negative, non-motile, coccobacillus -> endospores

 

•Bacteria are very small and often difficult to see in gram stain
Term

 

 

Rocky Mountain Spotted Fever

(Pathogenesis)

Definition
 
–Disease acquired from bite of a tick infected with R. rickettsii
–Bacteria are released into blood and taken up by cells lining vessels
–Bacteria enter cells through endocytosis
•After endocytosis, cell leaves protective phagosome
–Bacterial endotoxin released in bloodstream can cause disseminated intravascular coagulation

 

•This is recognized by shock and generalized bleeding
Term

 

 

Rocky Mountain Spotted Fever

(Epidemiology)

Definition

 

 

- A zoonosis transmitted by bite of infected tick, usually Dermacentor sp.

Term

 

 

 

Rocky Mountain Spotted Fever

(Prevention)

Definition

 


Avoidance of tick-infested areas, use of tick repellent, removal of ticks within 4 hrs of exposure

Term

 

 

 

Rocky Mountain Spotted Fever

(Treatment)

Definition

 



Doxycycline or Chloramphenicol

Term

 

 

Lyme Disease

(Symptoms)

Definition

 

–First Stage
•Characterized by skin rash that enlarges
•Other influenza-like symptoms can occur
–Later Stages

 

•Heart and nervous system impairment can occur
Term

 

 

Lyme Disease

(Causative Agent)


Definition
–Bacterium called Borreliaburgdorferi
–Large microaerophilic spirochete

Borrelia genome is linear and has numerous copies

Term

 

 

Lyme Disease

(Epidemiology)

Definition

 


Spread by the bite of ticks, lxodes sp., usually found iin association with animals such as white-footed mice and white-tailed deer living in wooded areas

Term

 

 

Lyme Disease

(Pathogenesis)

Definition

 

Spirochetes injected into the skin by an infected tick multiply and spread radially; the spirochetes enter the bloodstream and are carred throughout the body; the immune reaction to bacterial antigen causes tissue damage.

Term

 

 

Lyme Disease

(Prevention)

Definition

 

 

Protective clothing; tick repellents. 

Term

 

 

Lyme Disease

(Treatment)

Definition

 


Doxycycline and others; prolonged antibiotic therapy in chronic cases

Term

 

Cheeeeeekin Pox

(Causitive Agent)

Definition

 

 

Varicella-zoster virus; enveloped double-stranded DNA virus of the herpesvirus family

Term

 

 

Cheeeeeekin Pox

(Symptoms)

Definition
 
–Skin rash appears on back of head, face and mouth
•Rash progresses from red spots called macules to small bumps called papuales to small blisters called vesicles to pus filled blisters called pustules
•Lesions itch and appear at different times

 

•Healing begins after pustules break and crust over
Term

 

 

Cheeeeeekin Pox

(Epidemiology)

Definition
 
–Annual incidence once estimated in the several millions but declined due to vaccine
–Disease transmitted by respiratory secretions and skin lesions
–Incidences increase in winter and spring
–Viral incubation period approximately 2 weeks

 

•Infective 1 to 2 days before rash until blisters crust over
Term

 

 

Cheeeeeekin Pox

(Pathogenesis)

Definition

 


Upper respiratory viurs multiplication followed by dissemination via bloodstream to the skin; cytopathic effect of virus includes the formation of giant cells



Term

 

 

Measles

(Symptoms)

Definition
 
–Begins with fever, runny nose, cough, red weepy eyes
–Fine rash appears within a few days
–Symptoms generally disappear within 1 week
–Many cases complicated by secondary infections

 

•Pneumonia and earaches are most common secondary conditions
Term

 

 

Measles

(Causative Agent)

Definition

 

 

Rubeola virus, a single-stranded RNA virus of the paramyxovirus family

Term

 

 

Measles

(Prevention and Treatment)

Definition

 

 

Attenuated virus vaccine after age 12 months; second dose upon entering elementary school or at adolescence. No antiviral treatement available at present.

Term

 

 

Measles

(Pathogenesis)

Definition
 
–Infection via respiratory route
–Virus replicates in epithelium of upper respiratory tract
–Spreads to lymph nodes then to all parts of the body

 

–Infected mucous membranes important diagnostic sign
Term

 

 

Measles

(Epidemiology)

Definition
 
–Humans are only natural host
–Outbreaks still occur and are due to non- immune populations
–Virus spread by respiratory droplets
•Before routine immunization, over 99% of population infected
•Vaccine resulted in decline of annual cases

 

– no longer endemic in United States
Term

 

 

German Measles

(Pathogenesis)

Definition
 
–Enters body via respiratory route
–Virus multiplies in nasopharynx, then enters bloodstream
–Blood transports virus to body tissues

 

–Immunity develops against viral antigens
Term

 

 

German Measles

(Epidemiology)

Definition
 
–Humans are only natural host
–Disease is highly contagious
•Less so than measles (rubeola)
–40% of infected people fail to develop symptoms
•These individuals can spread virus

 

–Infectious 7 days before appearance of rash to 7 days after
Term

 

 

German Measles

(Causative Agent)

Definition

 

 

Rubella virus, an RNA virus of the togavirus family

Term

 

 

German Measles

(Symptoms)
Definition

 

 

Mild fever and cold symptoms, rash beginning on forehead and face, enlarged lymph nodes behind the ears

Term

 

 

 

German Measles

(Prevention and Treatment)
Definition

 

 

Attenuated rubella virus vaccine administered to children at 12-16 months, repeated at 4-6 yrs of age. No specific antiviral treatment.

Term

 

 

Tetanus

(Causative Agent)

Definition
 
Clostridium tetini
•Anaerobic
•Gram-negative
•Bacillus -> endospores
•Spore former 
•Swarming growth on laboratory media
Term

 

 

Tetanus

(Pathogenesis)

Definition
 
–Colonization is generally contained to wound
–Bacteria produce toxin
–Toxin composed of two chains
•Heavy chain binds receptors on motor neuron
•Lighter chain taken up through endocytosis
–Toxin blocks inhibition of motor neurons, causing paralysis

 

•Muscle contraction is uncontrolled
Term

 

 

Tetanus

(Symptoms)

Definition
 
–Divided into early and late symptoms
–Early symptoms
•Restlessness
•Irritability
•Difficulty swallowing
•Contraction of jaw muscles
•Convulsions

Particularly in children


–Later symptoms
•Increased muscle involvement
•Pain
•Difficulty breathing

 

•Death
Term

 

 

Tetanus

(Epidemiology)

Definition
 
C. tetani found in dirt and dust and GI tract of humans and animals
–Nearly half of infections result from puncture wounds including
•Body piercing, tattooing, animal bites, injected drug abuse
–30 to 60 cases in United States annually with 25% mortality rate

 

Immunization has decreased incidences in economically advanced countries  
Term

 

 

Tetanus 

(Prevention)

Definition
 
–Immunization best preventative
•Vaccine is inactivated tetanospasmin

 

–Given in combination with diphtheria and pertusis vaccine – DPT
Term

 

 

Tetanus

(Treatment)

Definition
 
–Thoroughly clean wound
•Remove all dead tissue
–Antimicrobial treatment given to kill multiplying bacteria
Metronidazole

  Antimicrobials do not kill   endospores

Antitoxin - antibody against tetanospasmin

 

•Neutralizes toxin not attached to nerve cells
Term

 

 

Gas Gangrene

(Symptoms)

Definition

 



Severe pain, gas and fluid seep from wound, blackening of overlying skin; shock and death commonly follow

Term

 

 

Gas Gangrene

(Causative Agent)

Definition

 

 

Usually Clostridium perfringens; other clostridia less frequently

Term

 

 

Gas Gangrene

(Pathogenesis)

Definition

 


Organism grows in dead and poorly oxygenated tissue and releases a-toxin; toxin kills leukocytes and normal tissue cells by degrading the lecithin component of their cell membranes; invlovement of muscle causes shock by unknown mechanism.

Term

 

 

 

Gas Gangrene

(Epidemiology)

Definition

 



Wounds of war; dirt contamination of wounds, tissue death, impaired circulation to tissue as in persons with poor circulation from diabetes and arteriosclerosis; self-induced abortions. 

Term

 

 

 

Gas Gangrene

Definition

Prevention and Treatment


Prompt cleaning and debridement of wounds is preventive; no vaccine available. Treatment: surgical removal of dirt and dead tissues of primary importance; hyperbaric oxygen of possible value; antibiotics to kill vegetative C. perfringens of marginal value. 

Term
Tomato juice agar
Definition
Selective
Term
Blood agar
Definition
Differential
Term
Snyder's agar
Definition
differential
Term
haemophilus influenza
Definition
Gram negative, bacillus (I have no mnemonic for this one)
Term
Streptococcus pneumoniae
Definition
Gram Positive, diplococci
Term
Klebsiellapneumoniae
Definition
Gram negative bacillus, capsule
MNEMONIC: double ll's
Term
Mycoplasma pneumoniae
Definition
Aerobic, lacks cell wall
Term
Bordetella pertussis
Definition
Gram negative, bacillus, capsule
MNEMONIC: double ll's
Term
Mycobacterium tuberculosis
Definition
Gram positive bacillus
MNEMONIC: there are t's in it, resembling a + sign; "tube" reminds me of a rod-shaped bacillus
Term
Pseudomonas aeruginosa
Definition
Gram negative, bacillus
MNEMONIC: no "t" in name, really nasty,thriving on oxygen ruining ppls lives
Term
Clostridium tetani
Definition
Gram negative, anaerobie
MNEMONIC: bacteria is shaped like a tennis racket, and a minus sign
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