Exam 3 Fastidious, Intracellular, Other Flashcards
Respiratory disease-causing bacteria
- Corynebacterium diphtheriae
- Bordatella pertussis
- Haemophilus influenzae
- Legionella pneumophila
- Mycoplasma pneumonia
Meningitis-causing bacteria
Listeria monocytogenes
STD bacteria
Chlamydia trachomatis
Zoonotic disease causing bacteria
- Francisella tularensis
- Rickettsia ricketsii
C. diphtheria has ____ growth on what agar?
aerobic; Loeffler’s agar or Tisdale’s (tellurite) agar
How is diphtheria transmitted?
Aerosol, human to human
youbreathe it out
Diphtheria causes disease in what part of the body?
Upper respiratory tract or skin
Where does C. diphtheria colonize?
Nasopharynx or adjacent regions
____ is responsible for the severe symptoms of diphtheria
Prophage-coded diphtheria toxin
Diphtheria causes a ____ in the back of the throat which can lead to _____
Thick covering; respiratory obstruction and myocarditis
Diphtheria - thick covering in the back of the throat presents as:
Pharyngitis with grayish adherent pseudomembrane
Diphtheria can lead to ____ damage
- kidney
- heart
- nerve
Diphtheria toxin is a phage tox gene produced by:
Lysogenized strains
Diphtheria toxin structure
A-B toxin
Diphtheria toxin blocks:
Protein synthesis
____ inhibits transcription of diphtheria toxin operon
Iron (corepressor)
Excess iron represses toxin production
A subunit of AB toxin - function
- Possesses catalytic activity
- inactivates elongation factor 2 (EF-2), prevents protein synthesis by ribosome
B subunit of AB toxin - function
Corynebacterium diphtheria
Membrane binding region
Diphtheria treatment
- DOC penicillin
- anti toxin
Prevention of diphtheria
Toxoid vaccine (DTAP)
True or false: diphtheria is rare in the US
True - due to effective vaccine
Diphtheria toxin is inactivated by:
Heat or chemical
Diphtheria is a _____ disease
Reportable (by law)
Bordatella pertussis classification
Gram negative coccobacillus
Bordatella pertussis causes:
Whooping cough
Bordatella pertussis invades what cells?
Alveolar macrophages
Bordatella pertussis is aerobic/nonaerobic
Strict aerobe
Whooping cough is described as:
- uncontrollable violent coughing
- hard to breathe
Whooping cough is highly _____. _____ are at greatest risk
Communicable; Children less than a year old
Whooping cough is endemic in the:
US
Whooping cough mortality before vaccination
21-31%
Bordatella pertussis virulence factors
- Adhesins (FHA)
- 2 distinct toxins (pertussis toxin, tracheal cytotoxin)
Bordatella pertussis adhesins
- filamentous hemagglutinin (FHA)
- pertactin
- fimbriae
____ is a major colonizing factor in nasopharynx
Bordatella pertussis
FHA
Bordatella pertussis
Pertussis toxin is secreted by ____
Type IV secretion system
Pertussis toxin function
increases mucus, leading to cough
Tracheal cytotoxin function
- damages respiratory tissues and paralyzes cilia
- leads to stagnant mucus and prevention of pathogen removal
- damage leads to paroxysmal cough
Tracheal cytotoxin damage leads to
Paroxysmal cough (whooping cough)
Bordatella pertussis - pertussis toxin pathogenesis
- AB toxin binds to ciliated respiratory cells
- unregulated activation of adenylate cyclase leads to increase in cAMP, increasing signal transduction
- increase in respiratory secretions and mucus
- mucus leads to coughing
Tracheal cytotoxin causes inflammation and ciliostasis to interfere with:
Secretions clearance
Where does Bordatella pertussis colonize?
Trachea - attach to cilia of respiratory epithelial cells
True or false: If you have whooping cough, you are most contagious during the paroxysmal (coughing) phase
False - you are more contagious (higher bacterial culture) during the catarrhal phase
More infectious before the cough starts
Bordatella pertussis diagnosis
PCR
Can culture but is is much slower
Bordatella pertussis DOC
Erythromycin
Whooping cough incidence is highest in ____ since 1955
2012
Decrease in whooping cough due to
DTAP vaccine
DTAP/Tdap vaccine contains ____ to stimulate immune response to toxin
inactivated tetanus toxin
Tdap must be given to all:
Pregnant women (between weeks 27-36)
H. influenza main virulence factor
- PRP capsule (antiphagocytic)
- Also has IgA protease and endotoxin
PRP capsule stands for:
Phosphoribosylribitol phosphate
Most serious serotype of H. flu
Type b (Hib)
H. influenzae grows as satellite colonies around:
S. aureus (secretes required growth factors - X factor and V factor)
H. influenzae causes major diseases among
Infants and elderly
H. influenzae infection can cause:
- epiglottitis (can be life threatening)
- meningitis (before vaccines)
- bacteremia
Before vaccines, H. flu meningitis was a major cause of:
90% of meningitis in children 6 months - 2 years
H. influenzae treatment
Broad spectrum antibiotics (cephalosporins, azithromycin)
Ampicillin resistant strains are common in _____ and conferred by ____
H. influenza; plasmid
True or false: there is no vaccine for H. influenzae
False - conjugate vaccine (PRP-tetanus toxoid) is very effective
H. flu ____ vaccine is poorly immunogenic
PRP capsule polysaccharide
When is H. flu vaccine administered?
- 2, 4, 6 months
- booster at 12 months
____ vaccine is T dependent, efficient, has good memory
Conjugate
True or false: H. influenzae cases have decreased
True due to effective Hib vaccine
< 1 case/100,000 children under 5 years of age
H. influenzae primarily affects:
unvaccinated/incompletely vaccinated children
H. influenzae and H. aegyptius can both cause:
Bacterial conjunctivitis
Legionella pneumophila killed 34 at:
American Legion convention in Philadelphia (1976)