Haemophilus influenzae

1. a. What growth factors does H. influenzae require?

X and V factors

b. Describe satellitism by H. influenzae.

Satellites around staph species or pneumococcus on SBA

2. How do humans get H. flu infections?

friends

3. a. Describe colonies/odor of H. flu on CA.

Mousy odor and grayish/beige colonies

b. Does H. flu require CO2? Explain.

no just enhanced with it

c. Describe the gram stain appearance of H. flu?

Gram negative tiny pleomorphic bacilli/coccobacilli Chinese letter forms

4. a. What is the basis for the H. flu serotypes?

looking at capsules

b. Which serotypes now most common causes of H. flu disease in the US?

see a lot more C (daycare kids)

5. a. Describe the antibiotic susceptibility testing of H. influenzae using:

(1) modified Kirby-Bauer

Streak MH+CA or HTM (Haemophilus Test Medium); contains isovitalex: Hemin/NAD); incubate in CO2 at 35C

5. a. Describe the antibiotic susceptibility testing of H. influenzae using:

(2) Etest-

mic

b. Why is beta-lactamase testing done on H. flu culture isolates?

Because it can often be beta lactamase positive, and isolates will make sure its only H. flu

6. a. What 3 specimens may be used for direct antigen testing for H. flu?

CSF, serum ,urine

b. What test (antigen and antibody) is most often used to detect H. flu culture

isolates?

Latex agglutination: latex coated with capsular antibody

7. a. Name 3 infections of H. flu common to young children (6 mos. -3 years).

meningitis
septicemia
epiglottitis/tracheitis

b. Name the H. flu biogroup/Haemophilus species that causes pink eye.

H. aegyptius (AKA, Kocks-Weeks bacillus) & H. influenzae biogroup III/ aegyptius cause acute, contagious conjunctivitis, called the "pink eye"

c. What respiratory infection does H. flu commonly cause in adults?

pneumonia

e. What 5 infections are caused by nonencapsulated strains of H. flu?

otitis media
sinusitis
conjunctivitis
pneumonia (elderly, or underlying lung problem)
bronchitis

8. a. Describe how colonies of Haemophilus influenzae would be detected and

identified from patient specimens (CSF, sputum, etc.) by the tech working up the culture.

Perform gram stain then plate to Chocolate
Quad plate then catalase test then oxidase positive, la porphyrin test negative, x and v on quad plate
Beta lactamase positive

b. What rapid antibiotic test would be performed on the isolae?

Haemophilus ducreyi

1. What infection does H. ducreyi cause?

STD - chancre and genital ulcers

2. What growth factor does H. ducreyi require?

X factor

3. How is H. ducreyi most often diagnosed?

direct semar of chancroid ( soft chancre)

4. Describe the distinct gram stain appearance of H. ducreyi in direct smears.

gram negative coccobacilli in chains "school of fish" arrangement