Catalase positive, beta-hemolytic staphylococcus:

Ans. is 'a' i.e., S. aureus (Ref: Essentials of Medical Microbiology, p. 779)* All staphylococci are catalase positive.* Amongst staphylococci, Staph, aureus and Staph, haemolyticus (CONS) are beta hemolytic.* Most species of coagulase negative staphylococcus species are non-hemolytic except Staph, haemolyticus.* Staphylococcus haemolyticus is a member of the coagulase-negative staphylococci (CoNS). It is part of the skin flora of humans, and its largest populations are usually found at the axillae, perineum, and inguinal areas. S. haemolyticus also colonizes primates and domestic animals. It is a well-known opportunistic pathogen, and is the second-most frequently isolated CoNS (S. epidermidis is the first).