The first outbreak of penicillinase producing strains of Neisseria gonorrhoeae (PPNG) in Amsterdam in 1981-2 was caused mainly by African strains carrying the 24 megadalton transfer plasmid (Afr+) that were non-requiring (NR) and inhibited by phenylalanine (pheni), but African strains without the transfer plasmid (Afr-) that were NRpheni and Afr+ NR strains were also found. Serological classifi...

With increasing concerns regarding diminishing treatment options for gonorrhea, maintaining the efficacy of currently used treatments and ensuring optimal Neisseria gonorrhoeae antimicrobial resistance surveillance are of the utmost importance. Penicillin is still used to treat gonorrhea in some parts of the world. In this study, we developed and validated a real-time PCR assay for the detectio...

17 Recent studies have shown that chromogenic cephalosporin tests are inferior to disc zone edge tests in 18 detecting penicillinase in Staphylococcus aureus isolates resulting in a change to CLSI and EUCAST 19 guidelines in 2012. We sought to confirm these findings using Australian isolates and compare the 20 performance of the CLSI and EUCAST methods which use different disc strengths, penici...

Elimination and transduction of drug resistance was examined in methicillin-resistant strains of Staphylococcus aureus. Irreversible spontaneous loss and "curing" by aging of cultures and by treatment with ethidium bromide indicated that the determinants for penicillinase production and chloramphenicol resistance, and probably also for neomycin resistance, were located extrachromosomally. On th...

17 Recent studies have shown that chromogenic cephalosporin tests are inferior to disc zone edge tests in 18 detecting penicillinase in Staphylococcus aureus isolates resulting in a change to CLSI and EUCAST 19 guidelines in 2012. We sought to confirm these findings using Australian isolates and compare the 20 performance of the CLSI and EUCAST methods which use different disc strengths, penici...

The in vitro sensitivity of 104 isolates of Neisseria gonorrhoeae to six antimicrobial agents was tested. More than 50% of the isolates produced penicillinase. Of those that did not produce penicillinase, 26% were resistant (minimum inhibitory concentration (MIC)) greater than or equal to 0.5 mg/l), and 68% showed a decreased sensitivity for penicillin G (0.06 less than or equal to MIC less tha...

Mitsuhashi, Susumu (Gunma University, Maebashi, Japan), Hajime Hashimoto, Megumi Kono, and Masato Morimura. Drug resistance of staphylococci. II. Joint elimination and joint transduction of the determinants of penicillinase production and resistance to macrolide antibiotics. J. Bacteriol. 89:988-992. 1965.-Strains of Staphylococcus aureus, which show high resistance to macrolide antibiotics (er...

The minimal inhibitory concentrations of 30 antibiotics were determined by the agar dilution method for 17 penicillinase-positive and 50 penicillinase-negative strains of Neisseria gonorrhoeae. The latter included 42 strains that were penicillin susceptible (pen S) (minimal inhibitory concentration, <0.125 mug/ml) and 8 strains with intermediate resistance to penicillin (pen I; minimal inhibito...