Distribution of the 3.05-Mdal Toronto β-lactamase plasmid among penicillinase-producing isolates of Neisseria gonorrhoeae in the Far East

: One hundred and fifty-two beta-lactamase-producing Neisseria gonorrhoeae isolates from Japan (n = 25; 1983, 1985, 1986), Taiwan (n = 14; 1983, 1984), and the Republics of Singapore (n = 58; 1986, 1987) and the Philippines (n = 55; 1989) isolated from 1983 through 1989 were characterized by auxotype, serovar, and plasmid content to determine the distribution and diversity of penicillinase-producing N. gonorrhoeae (PPNG) strains possessing the 3.05-Mdal "Toronto" beta-lactamase plasmid. PPNG isolates possessing a 3.05-Mdal beta-lactamase plasmid were isolated in Japan (1/25: 4%), Taiwan (4/14: 29%), and the Republic of the Philippines (3/55: 5%); no PPNG isolates with the 3.05-Mdal plasmid were isolated in the Republic of Singapore. All isolates possessing the 3.05-Mdal plasmid also possessed a 24.5-Mdal conjugative plasmid and belonged to the auxotype/serovar class, Proto/IB-1. Studies with five isolates possessing the 3.05-Mdal plasmid, and representing isolates from each country in which they were found, confirmed that the beta-lactamase plasmid in these strains could not be transferred to another gonococcal isolate by conjugation. PPNG isolates possessing the "Toronto" plasmid are widespread in the Far East; spread of these isolates may, however, be limited to the physical spread of a single strain.