Streptococci

Question 1

Classification of streptococci?

Answer 1

Gram-positive cocci which are either:
Alpha-haemolytic (partial haemolysis)
Beta-haemolytic
(complete haemolysis)

Question 2

Which types of BHS (beta-haemolytic strep) are important in human disease?

Answer 2

Group A (strep pyogenes)
Group B (neonatal meningitis +/- septicaemia)
Group D (enterococcus)

Question 3

Conditions caused DIRECTLY by GAS (group A strep)?

Answer 3

Tonsilitis

Skin infections- erysipelas, impetigo, cellulitis, necrotizing fasciitis

Question 4

Conditions caused by immunological reaction to/toxins released by GAS?

Answer 4

Rheumatic fever and post-strep glomerulonephritis (immune)
Scarlet fever (toxins)