15 Bordetella, Haemophilus, Moraxella Flashcards
what anatomical location are bordetella, haemophilus, and moraxells typically found?
upper airway
bordetella grows on what agar? Has what shape?
-bordet-gengou or regan-lowe-coccobacillus
T/F B. pertussis is aerobic? Non-fastidious?
-T-F
what is infection rate of whooping cough?
100% in unvaccinated (but may not show symptoms)
what 2 organisms cause whooping cough?
B. pertussis, parapertussis
pertussis is common in what age group?
less than 5 yrs
when did vaccination start for pertussis? before that, what was mortality rate?
1940’s1%
T/F recently there is an increase in pertussis?
T (non-vaccinaters)
T/F pertussis vaccination is world-wide?
F
Catarrhal stage pertussis how many weeks?
1-2 wks
paroxysmal stage pertussis how many weeks?
2-8
convalescent stage pertussis is what?
symptoms get better (after paroxysmal stage)
Which pertussis stage is most contagious?
catarrhal
List B. pertussis MAIN virulence factors? (3)
-filamentous hemagglutinin (adhere to glycolipids in CILIATED epithelium)-pertussis toxin (also an adhesion)-pertactin (adhere to cells)
what type of toxin is pertussis toxin? What’s its mechanism?
-A-B toxin, ADP-ribosylating-up Gs ->up adenylate cyclase ->up cAMP -> ions are expelled from cell ->paralyzes cell (up respiratory mucus)
List B. pertussis additional toxins? (4)
-cya toxin (anti-inflamm, anti-phagocytic)-dermonecrotic toxin-tracheal toxin (cilia paralysis)-endotoxin
pneumonia, otitis media, seizures, encephalopathy, death are complications of what disease?
pertussis [of these pneumonia is the MOST common. death is rare.]
What symptoms when a vaccinated individual gets pertussis?
90-day cough can be only symptom, or sometimes also scratchy throat, episodes of sweating, post-tussive vomiting
how do we vaccinate for pertussis?
purified B. pertussis components w/ D and T toxoids (DTaP for “acellular”)
what are the components of “aP” in pertussis vaccination/
pertussis toxoid, two colonization antigens and NO endotoxin
pertussis immunization schedule?
2,4,6,15-18 months, 4-6 yrs
T/F prophylactic antibiotics are provided to ALL close contacts of a pertussis case?
T
Haemophilus is coccus/Bacilli? anaerobe/aerobe? Transformable/not? Fastidious/not?
-coccobacilli-facultative anaerobe-NATURALLY transformable-Fastidious
T/F non-encapsulated Haemophilus influenza is found in human oral cavity and mucosal surfaces of upper resp. tract normally?
T. (80% of humans!) [occasionally healthy people also harbor encapsulated Hib]
Type-able strains of H. influenza have what serotype?
a-f (b most prevalent. This is the vaccinated strain!)
Non-typeable strains of H. influenza have capsule or not? cause disease or not?
-no, yes occasionally
When it comes to the disease it causes, how is H. parainfluenzae different than H. influenza?
same, but lower incidence
what strain of H. influenza is known for pink eye which can progress to Brazilian purpuric fever?
aegypticus
what strain of H. influenza causes “soft chancre/chancroid”?
H. ducreyi [mostly tropical, may not even be a real haemophilus!]
What diseases can H. influenza cause? (3 categories) [global card, review rather than memorize]
occasionally:-meningitis, epiglottitisRarely:-pneumonia, cellulitis, bacteremiaLocal:-otitis media, sinusitis, conjunctivitis
COPD is commonly exacerbated by what organism?
H. influenzae
Hib no longer causes what childhood problem post-CONJUGATE vaccination?
meningitis is kids under 5 yrs
What are Haemophilus Influenzae B. virulence factors?
-NO exotoxin!-anti-phagocytic + adhesin capsule in Hib only-LOS-neuraminidase & IgA protease (role in invasion unproven)
For non-type-B H. influenza, what are virulence factors?
unknown (NO exotoxin!)
growing H. influenze requires?
choc agar /w X (hemin) and V (NAD) at 37 degrees in CO2-enriched environment
besides growing, how can we diagnose H. influenza?
type b capsular antigen detection
Treat H. influenza with what? What is key to treatment?
-cefuroxime since it crosses Blood-Brain-Barrier (and since Beta-lactamases are common)-Prompt! (epiglottitis/meningitis 99% mortality)
Moraxella is similar to what pathogen?
Haemophilus
T/F 50% healthy kids and some adults have Moraxella flora?
T
Moraxella usually causes what diseases?
-otitis media in kids-sinusitis in adults-COPD exacerbations (like Haemophilus)
If Moraxella progresses to bacteremia what does this mean?
patient has other serious disease. (don’t usually progress)
Virulence factors of Moraxella?
-adhesins-LOS
How is Moraxella different from Haemophilus?
-diplococcus-grow on most agars!
How do we treat Moraxella?
-Beta-lactam plus B-lactamase inhibitor (like augmentin), or 2 or 3 gen. cephalosporins
How is Moraxella similar to Haemophilus?
-most things-oxidase positive-gram neg.
