A Microbiologist Is Reading a Sputum Culture on the Bench

Multiple Choice

A microbiologist is reading a sputum culture on the bench.There is growth on the sheep blood agar (SBA) and chocolate (CHOC) plates, but no growth on the MacConkey (MAC) plate.The colonies growing on the SBA have produced a wide, deep, clear zone of b-hemolysis around and under the colonies.What organism could this be?

A) Escherichia coli
B) Staphylococcus aureus
C) Streptococcus pyogenes
D) Streptococcus pneumoniae