A staphylococcal isolate that gives a negative result using the Cefinase disk and tests resistant to penicillin by disk diffusion means that:
A)the isolate may contain the mecA gene.
B)the bacteria produce the b-lactamase enzyme.
C)the isolate is also resistant to ampicillin,carbenicillin,ticarcillin,and imipenem.
D)the isolate is also resistant to oxacillin,cefoxitin,and ticarcillin-clavulanate.

Question

Quizplus · Accepted Answer

The negative Cefinase test indicates that the bacterium does not produce the b-lactamase enzyme;the organism be expressing its resistance to Penicillin due to the presence of the mecA gene product,an altered Penicillin-Binding Protein (i.e. ,PBP2a).

A Staphylococcal Isolate That Gives a Negative Result Using the Cefinase