Haemophilus (Exam 2)

Question 1

What is the gram stain morphology of Haemophilus sp.?

Answer 1

Gram negative coccobacilli or rods

Question 2

Are most Haemophilus species pathogenic or nonpathogenic?

Answer 2

Nonpathogenic

Question 3

What are the common agar growth requirements and why?

Answer 3

Haemophilus species often require chocolate agar for growth instead of SBA because they need X, V or X and V and SBA only contains X.

Question 4

H. influenzae growth requirements (X, V, X and V)?

Answer 4

Both X and V

Question 5

H. flu biogroup aegyptius growth requirements (X, V, X and V)?

Answer 5

Both X and V

Question 6

H. parainfluenzae growth requirements (X, V, X and V)?

Answer 6

Only V

Question 7

H. haemolyticus growth requirements (X, V, X and V)?

Answer 7

Both X and V

Question 8

H. parahaemolyticus growth requirements (X, V, X and V)?

Answer 8

Only V

Question 9

H. ducreyi growth requirements (X, V, X and V)?

Answer 9

Only X

Question 10

Does H. influenzae lyse HB or RB?

Answer 10

Neither

Question 11

Does H. flu biogroup aegyptius lyse HB or RB?

Answer 11

RB

Question 12

Does H. parainfluenzae lyse HB or RB?

Answer 12

RB (variable)

Question 13

Does H. haemolyticus lyse HB or RB?

Answer 13

Both

Question 14

Does H. parahaemolyticus lyse HB or RB?

Answer 14

Both

Question 15

Does H. ducreyi lyse HB or RB?

Answer 15

Neither

Question 16

Which Haemophilus species are ALA positive, or in other words, are X independent?

Answer 16

H. parainfluenzae and H. parahaemolyticus

Question 17

Which organism is known to have a “mousy” odor?

Answer 17

H. influenzae

Question 18

Which organism is the leading cause of meningitis in children less than 5 yo?

Answer 18

H. influenzae

Question 19

Which organism is one of the three most common organisms associated with conjunctivitis?

Answer 19

H. influenzae

Question 20

Of the H. influenzae serotypes, which is the most invasive prior to vaccination development?

Answer 20

Serotype B

Question 21

Which Haemophilus species is known to cause BFP (Brazilian purpuric fever) and conjuctivitus?

Answer 21

H. flu biogroup aegyptius

Question 22

Which Haemophilus species has tan, translucent, sometimes mucoid colonies?

Answer 22

H. influenzae

Question 23

Which Haemophilus species has the same colony morphology as H. influenzae, but smaller at 48 hrs?

Answer 23

H. flu biogroup aegyptius

Question 24

Which Haemophilus species is known to cause soft genital chancres?

Answer 24

H. ducreyi

Question 25

What are the growth conditions for H. ducreyi and where is the organism most commonly found?

Answer 25

High humidity and warm temperature (33C incubation); commonly found in disadvantaged populations in the tropics - swab must be placed on media within 10 minutes of collection

Question 26

Which Haemophilus species has small, flat, translucent, smooth and “scooty” colonies?

Answer 26

H. ducreyi

Question 27

Which Haemophilus species has a gram stain that looks like a school of fish or railroad tracks?

Answer 27

H. ducreyi