EPIDEMIOLOGY OF PENICILLIN-RESISTANT NEISSERIA-GONORRHOEAE ISOLATED IN TAIWAN, 1960-1990

The epidemiology of penicillin-susceptible Neisseria gonorrhoeae isolated in Taiwan from 1960 to 1990 is summarized. The isolation of N. gonorrhoeae less sensitive to penicillin (i.e., with intrinsic resistance) was first reported in 1960. The rate at which organisms less sensitive to penicillin (MIC, greater-than-or-equal-to 0.5-mu-g/mL) were isolated increased to 17%, 50%, 80.1%, and 88.8% in 1967, 1975, 1984, and 1990, respectively. Penicillinase-producing N. gonorrhoeae (PPNG) first appeared in Taiwan in late 1976, and the first six strains of PPNG isolated were from United States military servicemen who had relocated from Southeast Asia. The percentage of PPNG strains rose to 37.82% in 1982, and has remained high (50%-62%) since 1983. In the present study, resistance of N. gonorrhoeae to spectinomycin (MIC, > 32-mu-g/mL), third-generation cephalosporins (MIC, > 4-mu-g/mL), or quinolones (MIC, > 4-mu-g/mL) has not been found. Strains requiring arginine, hypoxanthine, and uracil for growth, which frequently cause disseminated gonococcal infections, were not isolated. PPNG strains tended to be of the prototrophic auxotype (55%); non-PPNG strains were mostly of the proline-requiring auxotype (48.8%). Two kinds of R plasmids were isolated in the PPNG strains: the 4.4-MD Asian type (82%-95%) and the 3.05-MD Toronto type (5%-18%). All of the PPNG strains possessing Toronto R plasmid were of the same auxotype/serotype (prototrophic/IB). Evidence suggests that the Asian-type R plasmid was imported into Taiwan in 1976, while the Toronto-type R plasmid may have first emerged in Taiwan in 1983. The epidemiology of PPNG strains isolated in various geographic areas of Taiwan and the world is also discussed.