Week 3 - Gram Negative Cocco-bacilli

Question 1

This Neisseria app can cause septicaemia and meningitis

Answer 1

Neisseria meningitidis

Question 2

Does Haemophilus influenzae grow on blood agar?

Answer 2

No, only chocolate agar

Question 3

What is X and V Factor and what species of Haemophilus requires both?

Answer 3

X Factor is haemin in blood
V Factor is NAD+ / NADH
Haemophilus influenzae requires both

Question 4

The plague is caused by what Gram negative cocco-bacilli?

Answer 4

Yersinia pestis

Question 5

Whooping cough is caused by what Gram negative cocco-bacilli?

Answer 5

Bordatella pertussis

Question 6

What antiphagocytic property does Neisseria meningitidis have?

Answer 6

Antiphagocytic capsule

Question 7

What virulence factor does Neisseria gonorrhea have?

Answer 7

Pili - adhesion to oral / urogenital mucosa (and can also attach to sperm)

Question 8

If intracellular diplococci in PMNs from a urogenital swab is diagnostic for Neisseria gonorrhea in males, why not so for females?

Answer 8

Because in females the bacteria may also be Moraxella spp or Acinetobacter spp.

Question 9

Neisseria gonorrhea is oxidase __________. What other test could differentiate between the species?

Answer 9

Positive

Sugar utilisation test (N. gonorrhea is Glucose + and Maltose/Sucrose -)

Question 10

What special media could you grow Neisseria gonorrhea on?

Answer 10

Chocolate agar or

Thayer-Martin agar - contains ABs and anti-fungals to inhibit growth of other bacteria and yeasts.

Question 11

A Haemophilus spp has been cultured using the BA/NA/S. aureus spot inoculation method. The results are as follows:

Satellite on both NA and BA agars.

What species of Haemophilus is present?

Answer 11

Haemophilus parainfluenzae