Haemophilus influenzae Flashcards
1
Q
Description of H. influenzae
A
- short coccobacillus
- G negative
- capsulated forms iridescent on BHI agar
2
Q
Requirement of H. influenzae for growth
A
-heme(Factor X) and NAD(Factor 5)
3
Q
Agar used
A
- chocolate blood agar
- satellite colonies on blood agar
4
Q
Typing of H. influenzae
A
- capsule typable by Quellung reaction
- most infections type b out of type a-f
5
Q
H. influenzae enters by
A
-URT mucosal in aerosolized form
6
Q
Clinic presentation of H. influenzae in fetuses
A
-stillbirth if less than 24wks
7
Q
Clinic presentation of H. influenzae in children
A
- meningitis
- acute onset of headache, stiff neck, coma
- late sequelae involving brain damage
- acute otitis media
- bacteremia; may cause organ failure
- pharyngitis, bronchitis, epiglottis
- tear duct; conjunctivitis
8
Q
Clinic presentation of H. influenzae in adults
A
-pneumonia, sinusitis, epiglottis
9
Q
H. influenzae commonly responsible for
A
- bacterial meningitis
- overall, 7%
- common in kids
10
Q
3 things responsible for acute otitis media
A
- H. influenzae
- Strep pneumoniae
- Moraxella catarrhalis
11
Q
Description of H. aegyptius
A
- conjunctivitis
- purpuric fever
12
Q
Description of H. ducreyi
A
-chancroid; papules and ulcers of genitals, LN
13
Q
Epidemiology of H. influenzai
A
- carrier rate 75%
- spread via droplets from infected
- highly contagious
- most adults immune
14
Q
Pathogenesis of H. influenzai
A
- adhesion via pili and proteins; uptake and growth
- IgA protease
- lipooligosaccharide(LOS)
- T cell activation by soluble PG
- main virulence is poly-ribosylribitol phosphate(PRP)
- PRP allows invasion of capillaries and CNS
15
Q
Control of H. influenzai
A
- vaccine; conjugated to diptheria toxoid for children
- amoxycillin, 3rd generation ceph. but diarrhea chance
- rifampin for prophylaxis
