Haemophilus and Moraxella

Question 1

Haemophilus

Gram
Shape
Treatment

Answer 1

Gram (-)
Coccobacilli
Penicillin, amoxicillin, ceftriaxone

Question 2

What are the two growth requirements for Haemophilus?

Answer 2

1. X-factor (hemin) - must lyse RBC to release it (like in chocolate agar)
2. V-factor (NAD) - diffuses from RBC

Question 3

Virulence factor of Haemophilus that damages tissues and causes inflammation?

Answer 3

Lipooligosaccharide (LOS)

Question 4

Rate the virulence of the following from greatest to least.:

Moraxella, H parainfluenzae, HITB, NTHI

Answer 4

HITB&raquo_space;NTHI&raquo_space; Moraxella > H. parainfluenzae

Question 5

Haemophilus influenza type B (HITB)

Encapsulated?
Required growth factors?
Diseases
Virulence factor
Vaccine
Site of colonization
Spreads via

Answer 5

• Yes
• X and V, chocolate blood agar
• Meningitis (mostly pediatric), cellulitis, epiglottis swelling, primary bacteremia, septic arthritis
• H. influenzae type b (HIB) capsule: polyribosyl ribitol phosphate (PRP)
• Nasopharynx
• Direct contact, secretions, aerosol

Question 6

Haemophilus vaccine

Answer 6

HITB/HIB: - Protein-conjugate capsular polysaccharide

Question 7

Haemophilus influenza - unencapsulated, nontypable (NTHI)

• Required growth factors
• Diseases
• Site of proliferation

Answer 7

• X and V, chocolate blood agar
• Purulent sinusitis, otitis media, exacerbation of bronchitis/COPD, pneumonia, puerperal fever
• Damaged/inflamed tissues (lower respiratory tract of smokers, patients with resp virus, middle ear/sinuses, etc)

Question 8

What most commonly causes purulent sinusitis and otitis media?

Answer 8

Haemophilus influenza

Question 9

T or F. NTHI spreads by local invasion.

Answer 9

False - unlike HITB

Question 10

H. parainfluenzae

Growth factors?
Diseases

Answer 10

• Only V, grows on blood agar

- Sinusitis, bronchitis

Question 11

H. ducreyi

Disease?

Answer 11

Chancroid-veneral ulcer (extremly painful) on genitals, looks shaggy; enlargement of local lymph nodes

Question 12

H. influenza biogroup aegyptius

Disease?
Virulence factor?

Answer 12

Brazilian hemorrhagic fever, conjunctivitis, bronchopneumonia, sepsis, shock, DIC

Plasmid conveys special virulence

Question 13

Moraxella catarrhalis

Gram
Shape
Diseases
Site of inhabitation

Answer 13

• Gram (-)
• Diplococci
• Exacerbation of COPD, otitis media and sinusitis
• Nasopharynx