HAEMOPHILUS!!! MICROM 442 deck 16

Question 1

8 pathogenic species

Answer 1

– H. influenzae (1.8MB)
– H. aegyptius
– H. parainfluenzae
– H. haemolyticus
– H. ducreyi (2.8MB)

Question 2

GM???

Answer 2

negative

Question 3

shape?

Answer 3

cocobacilli

Question 4

media?

Answer 4

Chocolate agar

Question 5

what type of colonies form?

Answer 5

smooth, flat/convex

Question 6

type of anaerobe?

Answer 6

facultative

Question 7

do she move around?

Answer 7

no, non-motile

Question 8

spores?

Answer 8

no

Question 9

– Protoporphyrin IX (from hemin) = X factor
– Nicotinamide adenine dinucleotide (NAD) = V factor

Answer 9

Fastidious (especially non-H. influenzae)

Question 10

they do NOT ferment lactate, what do they ferment?

Answer 10

glucose -> H.ducreyi

Question 11

ALL species are oxidase

Answer 11

positive

Question 12

reduce what to what?

Answer 12

Reduce nitrate to nitrite

Question 13

SOME species are catalase

Answer 13

negative (ducreyi & parainfluenzae)

Question 14

H. influenzae when encapsulated

Answer 14

– Type B → VACCINE PREVENTABLE (Hib)
– Polysaccharide capsule, key virulence factor
– Uncommon colonizer, BSI more likely

Question 15

h. influenzae when NTHI (non-encapsulated)

Answer 15

– URT / nasopharyngeal colonizer
– Majority of disease now NTHI
– Strain-specific immunity (recurrences)

Question 16

Hib Vaccine

Answer 16

> Conjugate vaccine
– Type B capsule (PRP)
– Polyribosyl-ribitol-phosphate
Series started at 2 mos

Question 17

consequences of type B capsule vax?

Answer 17

drops overall incidence but also creates niches for other serotypes, especially NTHI

Question 18

Anatomical Basis of
H. influenzae
diseases

Answer 18

Focus on URT-contiguous sites

Question 19

Anatomical Basis of
H. influenzae
diseases

Answer 19

> Blood stream infection (BSI), hematogenous spread
– endocarditis (HACEK orgs)
– Septic arthritis
– BSI more common with Type B vs NTHI

Question 20

Lower Respiratory Tract Infection

Answer 20

> Pneumonia
– Often insidious
– Two patient pops
Kids 4mos – 4yrs
(Older) adults with bronchociliary dysfunction (COPD, smoking)
Uncommon cause of community acquired PNA (CAP)
NTHI important cause of COPD exacerbations
– ~15% of invasive Hib (pre-vaccine)

Question 21

Capsule virulence factors

Answer 21

(esp type B)

Question 22

Adhesins

Answer 22

Protein E, OMP2, Type IV Pilus, other
fimbriae

Question 23

ceftriaxone, cefotax,
amp-sulbactam

Answer 23

IV abx for more series infx

Question 24

if R

Answer 24

Amoxicillin or Amox-Clavulanate

Question 25

H. ducreyi

Answer 25

> STI with ulcerated lesions, adenopathy, pain
Heterosexual transmission dominant
– M > F (9:1), F = carriers?
Low SES, contact with sex workers
Co-occur with other STIs
Readily treated!
No life-long immunity (reinfection)

Question 26

chancroid -> associated with H. ducreyi

Answer 26

-PAINFUL
-multuple lesions
-exudate = yellow/grey
-INFECTIOUS LESIONS

Question 27

primary syphillis -> T.pallidum

Answer 27

-NOT painful
-often single lesion
-clear exudate
-INFECTIOUS LESIONS

Question 28

HOW DO WE TELL H. INFLUENZAE FROM B. PERTUSSIS?????

Answer 28

deferentially cultured