Plasmid profiles of Neisseria gonorrhoeae in Peninsular Malaysia

The plasmid profiles of 160 strains of Neisseria gonorrhoeae isolated in Peninsular Malaysia, comprising 80 penicillinase-producing (PPNG) and 80 non-penicillinase-producing (non-PPNG) isolates, were determined. The 80 PPNG isolates were divided into two plasmid groups. All of them harbored two common plasmid species, a 4.4 megadalton (Md) R plasmid previously associated with beta-lactamase production in PPNG strains from the Far East and a 2.6 Md multicopy plasmid of unknown function. In addition to these two plasmids, 60 (75%) PPNG isolates also carried a large 24.5 Md conjugative plasmid. In contrast, the 80 non-PPNG strains were divided into three plasmid groups. All of them possessed the 2.6 Md cryptic plasmid, and 35 (44%) isolates also harbored the 24.5 Md transfer plasmid. Besides these two plasmids, one non-PPNG isolate carried an additional 7.8 Md cryptic plasmid.