Nocardia sp, Actinomyces sp, Bacillus cereus

Question 1

What is the main microbiolgical distinction between Nocardia spp and Actinomyces spp?

Answer 1

Nocardia spp -> stains acid fast stain
Actinomyces spp–> doesnt stain acid-fast sain

Question 2

Trasmission of Nocardia spp?

Answer 2

Saprophytes in soil, organic matter & water -> direct inoculation on skin, soft tissues or inhalation

Question 3

Clinical syndroms attributed to Nocardia spp

Answer 3

1) Pyogenic skin infection
2) endobronchial inflammatory masses,
3) pneumonia w/ lung abscesses,
4) cavitation,
5) fistulas,
6) CNS dissemination (accompanies pulmonary infection)

Question 4

Clinical Syndroms attributed to Actinomyces spp

Answer 4

1) Extensive fibrosis,
2) oral, cervicofacial disease (perimandibular lesions, sinus tract formation with pus)
3) jaw osteonecrosis,
4) relapsing pneumonia (spontaneous drainage of empyema through chest wall),
5) thoracic fistulas —> may extend into the mediastinum
6) pulmonary masses, lung abscesses,
7) breaches of GI mucosa - abscess or firm mass ,
8) in females–> ascending Abdominal infection from intrauterine spiral use

Question 5

Diagnosis of Actinomyces spp

Answer 5

Culture: Gram (+), filamentous bacilli, sulfure granules (Visceral &skin)
* does not stain acid-fast

Question 6

Diagnosis of Nocardia

Answer 6

Gram (+) aerobic actinomycetes, sulphure granules (soft tissue&skin)
* **Stains acid-fast stain **

Question 7

Foodborne ilness attributed to Bacillus Cereus

Answer 7

Ingestion of Bacillus toxins Emetic and Diarrheal results in 2 distinct GI syndroms:
1) Emetic: emetic toxin, severe vomiting, caused by Reheated rice
2) Diarrheal : watery diarrhea, 8-16 h after ingestion of meat, vegetables and sauces (cooking destroys enterotoxins)

Question 8

Diagnosis of Bacillus spp

Answer 8

Gram (+) rod, form endospores

Question 9

Diagnosis of what agent?

Answer 9

Actinomyces spp (A.israelii)

Question 10

Diagnosis of what agent?

Answer 10

Nocardia spp