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

Question

Quizplus · Accepted Answer

E.coli will grow on all three plates, not just SBA and CHOC.Staphylococcus aureus will produce b-hemolysis on the SBA plate Streptococcus pyogenes will produce a wide, deep, clear zone of b-hemolysis on SBA.Streptococcus pneumoniae produces a-hemolysis on SBA.

A Microbiologist Is Reading a Sputum Culture on the Bench