Miscellaneous Gram-Negative Bacilli Pt 2

Question 1

All Haemophilus sp are catalse (+) except:

Answer 1

H. ducreyi & A. aprophilus

Question 2

Appearance on BAP of Haemophilus species with a requirement for V factor

Answer 2

Satellitism

Question 3

Common name of H. influenzae

Answer 3

Pfeiffer’s bacillus

Question 4

S. ____, S. ____ & Neisseria produce V factor ad by-product of metabolism.

Answer 4

aureus, pneumoniae

Question 5

TRUE or FALSE: Encapsulated H. influenzae species may be recovered as part of the NF of the upper RT and oral cavity/

Answer 5

False

Non-encapsulated

Question 6

H. influenzae serotype that is most virulent and most common cause of meningitis.

Answer 6

Serotype B

Question 7

Capsular constituent of Hib

Answer 7

Polyribosyl ribitol phosphate (PRP)

Question 8

Non-encapsulated strains of H. influenzae; localized infections

Answer 8

Non-typable H. influenzae

NTHi

Question 9

TRUE or FALSE: Encapsulated strains cause more invasive disease.

Answer 9

True

Question 10

H. influenzae biogroup causing pediatric conjunctivitis & Brazilian purpuric fever (BPF)

Answer 10

H. influenzae biogroup aegyptius

Question 11

What is the common name of H. ducreyi?

Answer 11

Ducrey’s bacillus

Question 12

Haemophilus sp causing chancroid/soft chancre (genital ulcer disease)

Answer 12

H. ducreyi

Question 13

Common name - Koch-Weeks bacillus

Answer 13

H. aegyptius

Question 14

What is the causative agent of native and prosthetic valve endocarditis?

Answer 14

H. parainfluenzae

Question 15

TRUE or FALSE: Haemophilus sp are very very fastidious.

Answer 15

True

Question 16

What is the preferred isolation medium of Haemophilus?

Answer 16

CAP (37C, 5-10% CO2)

Question 17

In identifying Haemophilus, CAP is supplemented with ____ to reduce overgrowth of normal RT flora.

Answer 17

Bacitracin

Question 18

What is the preferred isolation medium of H. ducreyi?

Answer 18

Nairobi biplate (33C)

Question 19

Clear medium with X and V factors; showing iridescent colonies of encapsulated H. influenzae

Answer 19

Levinthal agar

Question 20

Odor of H. inluenzae

Answer 20

Mousy/bleach-like

Question 21

Small, flat, non-mucoid, transparent to opaque or tan/yellow on CAP

Answer 21

H. ducreyi

Question 22

What is the appearance of H. ducreyi under the microscope?

Answer 22

Schools of fish/railroad track/finger print

Question 23

What is the smallest pathogenic bacillus?

Answer 23

H. ducreyi

Question 24

Test based on the ability of the organism to covert D-ALA into porphyrins and porphobilinogen

Answer 24

Porphyrin test (D-aminolevulinic acid)

Question 25

In the porphyrin test, porphobilinogen is detected by the addition of Kovac’s reagent or ____ (scientific name).

Answer 25

p-dimethylaminobenzaldehyde

Question 26

Positive result in the porphyrin test

Answer 26

Brick red fluorescence

Question 27

TRUE or FALSE: Results are positive in the porphyrin test if they are organisms that do not require exogenous X factor (able to synthesize X factor endogenously).

Answer 27

True

Question 28

Negative result in the porphyrin test

Answer 28

Bluish

Question 29

What is the UV light used to detect fluorescence in the porphyrin test?

Answer 29

Wood’s lamp