Streptococcus Pyogenes

Question 1

Basic Characteristics

Answer 1

Gram positive, catalase negative, beta haemolytic, lancefield group A

Question 2

Infections

Answer 2

Pharyngitis- strept throat 
Soft tissue- impetigo, erysipelas
Scarlet fever
TSS
Rheumatic fever

Question 3

Symptoms of pharyngits

Answer 3

pyrexia, anorexia, dysphagia, no cough, tonsillar exudate, painful cervical lymphoadenophathy

Question 4

Symptoms of scarlet fever

Answer 4

sandpaper, erythramous rash, general feeling of unwell, red face

Question 5

STTS symptoms

Answer 5

hypotension, pain, fever, chills

Question 6

Virulence factors

Answer 6

Hylauranic acid capsule, M proteins, Toxin

Question 7

Types of Toxins

Answer 7

Pyrogenic exotoxins- A, B and C. A and C superantigen to cause an over immune response by activating MHC and TCR. C responsible in tissue destruction.
Streptokinase- plasminogen to plasmin to cause lysis of clots.
Streptolysins- O and S. O for immune cells such as WBCs and platelets. S for other cells like RBCs.

Question 8

Isolate on?

Answer 8

Blood agar

Question 9

Confirmatory tests

Answer 9

Bacitracin

Lancefield