Objective-To study the epidemiology of Neisseria gonorrhoeae that exhibit both chromosomal and plasmid-mediated resistance to penicillin. Materials and methods-A total of 1589 strains of N gonorrhoeae isolated from patients attending St Mary's Hospital, London were tested for both their susceptibility to penicillin and for their auxotype and serotype. Results-Of the 940 non-penicillinase produc...

In a previous publication Bondi and Dietz (1947) reported that various factors could influence the susceptibility of penicillinase-producing bacteria to penicillin. The authors concluded that individual cells of certain organisms that produce this enzyme may be just as susceptible to penicillin as those of organisms that do not produce penicillinase. In a continuation of this study, the effect ...

Practical problems in the detection of penicillinase are discussed. A membrane technique for this purpose is described, with various modifications, suitable for screening large numbers of organisms and yet more sensitive than most methods.A one-stage membrane technique is adequate for detecting hydrolysis of penicillin G but a two-stage technique is required to demonstrate hydrolysis of some ot...

Growth of Stapylococcus aureus in various ionic surface-active agents resulted in loss of the ability to produce penicillinase, whereas growth in nonionic surface-active agents had no effect on penicillinase production. The curing effect of various alkyl sulfates was found to be dependent upon the chain length. Curing by surface-active agents could be inhibited by magnesium. Reciprocal transduc...

The in vitro activity of lysostaphin against clinical isolates of Staphylococcus aureus was determined by conventional tube-dilution methods. For comparison, minimal inhibitory concentration (MIC) values were also determined for penicillin G, ampicillin, methicillin, ristocetin, vancomycin, and erythromycin. Phage type and penicillinase and coagulase production were determined for each isolate....

This appears to be the first report of the isolation of a penicillinase-producing strain of Neisseria gonorrhoeae in the Netherlands. The presence of a penicillinase-producing gonococcal strain (PPGS) was demonstrated in two of a group of three patients with gonorrhoea. In addition, a penicillin- and ampicillin-sensitive gonococcus strain was isolated from all three patients. The PPGS was most ...