[Detection of penicillinase activity and its relation to other properties in staphylococci]

Comparison of the microbiological, iodometric and acidometric methods for determination of the penicillinase activity of staphylococci showed that the acidometric method was the simplest from the technical viewpoint and available for a wide range of laboratories. Penicillinase is more often produced by Staph. aureus than by Staph. epidermidis. No clear differences between production of penicillinase by various biovars of Staph. epidermidis were detected. The penicillinase activity was most often observed in the strains resistant to penicillin, erythromycin and ther antibiotics. No strains sensitive to zinc and silicon were isolated. Among Staph. aureus 96.15, 84.38, 78.18 and 64.71 per cent of the strains resistant to the ions of cadmium, mercury, plumbum and arsenic respectively produced penicillinase. No such definite results were obtained with respect to the strains of both the whole species of Staph. epidermidis and its separate biovars.