Flashcards in Haemophilus and Pertussis Deck (35):
gram neg rod
haemophilus is associated with what other disease?
typeable vs nontypeable
encapsulated vs non encapsulated
what types of disease does encapsulated haemophilus cause?
respiratory infections and bacterial meningitis in kids
can progress to:
bacteremia, meningitis, epiglotitits, cellulitis, or joint infections
before Hib vaccine, leading cause of bacterial meningitis in kids
what types of disease does unencapsulated haemophilus cause?
desseminate disease in compromised individual
what are the haemophilus capsule made of
a-f are important, b is the worst
helps avoid immune system- antiphagocytic and anti-complement
who carries haemophilus
where does haemophilus live?
nose, spreads via aerosolied form
is there a haemophilus vaccine?
yes- to the b encapsulated form
vaccine was originally to capsule, more recently conjugated to protein
encapsulated Hi pathogensis
endotoxins covered by capsule, so only contributes in bacteremia
Hib- LPS covered with choline
encapsulated Hi immunity
passive from mother for a few months
children susceptible from 6-12 months
acquire active immunity at about 3-4 years of age
treatment of Hib infection
for meningitis- 3rd gen cephlosporin or augmentin
low mortality with early treatment
prophylactic rifampin for contacts
nontypeable Hi pathogenesis
causes respiratory and ear infections, conjuctivitis
colonization starts in nasopharynx
kids get ear infections thru shorter eustachian tubes
only causes meningitis in compromised patients
adhesins found in both types of Hi promote colonization'
so much variability that they arent good vaccine targets
is nonencapsulated Hi intra or extra cellular?
vaccines for unencapsulate Hi?
treatment for NTHI
treatment for otitis media- amoxicillin (resistant strain has b-lactamase inhibitor added)
Hi growth and metabolism
no diagnostic fermentation
fragile and fastidious
doesnt grow on blood agar- uses chocolate agar
needs X factor- hemin, and v factor- NAD
these growth properties are used to identify
diagnosis of Hib
culture and blood/csf
presence of type b Ag
bordetella pertussis causes what?
bordetella pertussis morphology
gram negative coccobacillus
bordetella pertussis type of metabolism
bordetella pertussis transmission
bordetella pertussis incubation period
whoop is caused by what?
strong inhalation following cough through a narrowed glottis
what age group is hit worst by bordetella pertussis?
is there bacteremia in bordetella pertussis
exotoxins in bordetella pertussis
pertussis toxin- increases cAMP
causes: effects innate immunity, increases insulin, sensitization to histamine
adenylate cyclase toxin- increases cAMP
dermonecrotic toxin- interacts w/ actin polymerization
causes local necrosis and inflammation
other toxins frombordetella pertussis
tracheal cytotoxin- peptidoglycan stops cilia from beating and kills cells. causes inflammtion
LPS- activates innate immune system
bordetella pertussis adhesive virulence factors
pili- mediates attachment to respiratory tract
Fha- binds galactose
pertactin- outer membrane molecule
tracheal colonization factor- outer membrane molecule
bordetella pertussis vaccine
pertussis toxoid, fha, pertactin all part of vaccine
part of DTaP
reasons for increase in bordetella pertussis disease
waning immunity, Ag divergence, mutation of PTX, or decreased vaccination
diagnosis of bordetella pertussis
isolation of organism
history of contacts
detection of bordetella pertussis
must be cultured of bordet gengou agar- special