New method for detecting in vitro inactivation of penicillins by Haemophilus influenzae and Staphlycoccus aureus

A new technique for detecting penicillinase production in Haemophilus influenzae and Staphylococcus aureus was compared with the capillary procedure for detecting beta-lactamase and the Bauer-Kirby disk susceptibility procedure. Isolates were classified similarly by all three procedures.