Gram-Positive Bacteria

Question 1

Staphylococcus Morphology:

(3 main points)

1. 2. 3.

Answer 1

Staphylococcus Morphology

1. Gram-positive cocci
2. Grape-like clusters
3. Catalase-positive

Question 2

What is this?

Answer 2

Staphylococcus

Question 3

Which staphylococci are coagulase negative?

Answer 3

Staphylococcus Epidermidis & Saprophyticus

Question 4

Which staphylococcus is coagulase positive?

Answer 4

Staphylococcus Aureus

Question 5

How is S. Aureus transmitted and who is most often compromised?

Answer 5

Hospital-acquired (nosocomial)

Immunocompromised & IV Drug Users

Question 6

What protein is involved in Staphylococcus spp. infections?

Answer 6

Protein A: binds Fc portion of IgG to protect inhibiting complement activation and phagocytosis

Question 7

S. Aureus has two divisions of clinical disease:

1. (direct infection of affected tissue)
2. (no infection/infection at site distant to clinical manifestation)

Answer 7

S. Aureus Clinical divisions:

1. Purulent/suppurative or inflammatory diseases
2. Toxic disease

Question 8

What are the 6 purulent/inflammatory manifestations of S. Aureus

1. (Impetigo, folliculitis, furuncles, carbuncles, wound infections, cellulitis)
2. (metastatic/systemic)
3. (vegetative lesions)
4. (bone)
5. (joints)
6. (lungs)

Answer 8

S. Aureus Clinical purulent/ inflammatory Manifestations:

1. Cutaneous infections (Impetigo, folliculitis, furuncles, carbuncles, wound infections, cellulitis)
2. Bacteremia (metastatic/systemic)
3. Endocarditis (vegetative lesions)
4. Osteomyelitis
5. Septic Arthritis
6. Pneumonia

Question 9

What are the 3 Toxic manifestations of S. Aureus?

1. ingestion of heat-stable enterotoxin (NO fever)
2. (TSST-1)
3. (perioral erythema)

Answer 9

3 Toxic manifestations of S. Aureus:

1. Food poisoning
2. Toxic Shock Syndrome (caused by TSST-1)
3. Scalded Skin Syndrome (SSS toxin)