beta-Lactamase detection in nine staphylococcal species.

Detection of beta-lactamase by four different techniques (two acidometric, one chromogenic cephalosporin, and one iodometric) was evaluated with 79 isolates of nine different species of staphylococci. Overall, each technique detected more positive isolates when beta-lactamase production had been induced with oxacillin before testing, and each technique performed equally well when organisms were tested after induction.