micro 1

Question 1

which organism creates star-shaped colonies?

Answer 1

N. asteroids (pulmonary nocardia)

Question 2

what pathogen causes cutaneous Nocardia and what disease does it cause?

Answer 2

N. braziliensis
causes → cutaneous disease/ cellulitis with lymphatic involvement, subcutaneous disease ± abscess

Question 3

leywen-stin jenson media

Answer 3

TB culture media (used for Nocardia)

Question 4

what do you give people with Nocardia?

Answer 4

co-trimoxazole (Trimethoprim/ sulfamethoxazole)

Question 5

what are the general characteristics and types of Klebsiella?

Answer 5

• facultative anaerobes
• gram-negative bacilli
• capsulated → (mucoid colonies)

✓ Types: K. pneumoniae, K. oxytoca, K. ozaenae & K. rhinoscleromatis

Question 6

what is ozena and what causes it?

Answer 6

K. ozaenae → Ozena (atrophic rhinitis with nasal crusting, discharge, & very bad nasal
smell)

Question 7

what organisms are oxidase-positive

Answer 7

1. Pseudomonas (non-fermenter)
2. Neisseria
3. Vibrio
4. Brucella
5. Campylobacter
6. Helicobacter

Question 8

causative organisms of cystic fibrosis

Answer 8

S aureus, Ps. aeruginosa & Burkholderia cepacia complex.

Question 9

what strains cause P. ari pigmentation

Answer 9

1- Pyocyanin → greenish-blue colony
2. Pyoverdin
3. Pyorubrin (red).
4. Melanin (brown)

Question 10

what are the virulence factors of P. aeruginosa

Answer 10

2 exotoxins:
1- exotoxin A (inhibits protein)
2- exo-enzyme S (in burn patients)
- Proteases
- Phospholipases
- Alginate-like exopolysaccharide

Question 11

what is melioidosis (Whitemore’s disease) and what organism causes it?

Answer 11

pulmonary infection (like TB) with multiple abscesses
- Suppurative parotitis in children.
- caused by Burkholderia pseudomallei

Question 12

buffer charcoal yeast extract agar (BCYE) is used with

Answer 12

Legionella pneumophila (cut-glass appearance)

Question 13

does Pontiac fever cause pneumonic illness?

Answer 13

NO

Question 14

what is toxoplasma pneumonitis associated with

Answer 14

HIV/AIDS patients

Question 15

Paragonimus westermani life cycle:

Answer 15

• the infective stage→ metacercariae
• The first intermediate hosts → snails
• Second intermediate hosts → crabs or crayfish
• definitive host → humans
• diagnostic stage > eggs

Question 16

what are some examples of glucose non-fermenters GNB? (4)

Answer 16

1* Acinetobacter spp
2* Alcaligenes & Achromobacter spp.
3* Eikenella corrodens.
4* Flavobacterium meningosepticum.

Question 17

examples of primary atypical pneumonia (5)

Answer 17

1. Mycoplasma pneumoniae.
2. Legionnaire’s diz.
3. Q fever (coxilla burnitii)
4. Psittacosis.
5. Viral pneumonia e.g. flu