Ans. (a) Catalase positivity Pyoderma (Impetigo Superficial infection of the skin, caused primarily by Group A Streptococci and Staphylococci Usual site of infection are face (paicularly around nose and mouth) and the legs Diagnosis is based on the culture and staining of indeginous lesion. Gram positive cocci if catalase positive, than it is most likely to be Staphylococci and if catalase negative than it is Streptococci