Infection: Steptococcus pyogenes

Question 1

What is the classification of streptococcus pyogenes?

Answer 1

Gram positive cocci (appear as a string of beads)

Question 2

Where is strep pyogenes usually found on the body?

Answer 2

Part of the normal skin flora

Question 3

What are the methods of transmission of strep pyogenes?

Answer 3

Via respiratory droplets
Direct contact with skin
From cattle to humans via contaminated food

Question 4

What infections are caused by strep pyogenes?

Answer 4

Upper resp tract infections eg pharyngitis
Skin and soft tissue infections
Acute glomerulonephritis
Scarlet fever - throat infections which release toxins

Question 5

What are some of strep pyogenes virulence factors?

Answer 5

• Has a hyaluronic acid capsule which protects the bacterium from phagocytosis
• M protein in the cell wall prevents opsonisation

Question 6

How are strep pyogenes infections treated?

Answer 6

Sensitive to penicillin

if allergic give erythromycin