Sterile Penicillinase from Phage-lysed Staphylococci

Abstract

PENICILLINASE is more difficult to prepare from Staphylococci than from Bacillus cereus because staphylococcal penicillinase diffuses little, if at all, from the bacterial cells into the medium in which they are grown, whereas that produced from B. cereus diffuses freely. In fact, some authors state that they could not detect ‘extracellular’ staphylococcal penicillinase^1–5, although others claim that they could detect it in supernatant fluids^6,7 or filtrates^8,9 or by its diffusion into agar¹⁰. Some of the preparations used as staphylococcal penicillinase consisted of whole culture or cells^3,11, acetone and ether extracts¹², or cells disrupted by sonic vibration¹³ or in a Nossal tissue disintegration⁵. The possibility of using phagelysed Staphylococci as a source of penicillinase was suggested by Wallmark, G. (personal communication), while he was working in this laboratory. The following method was evolved.