Abstract: Objective To monitor antibiotic resistance of Neisseria gonorrhoeae in Nanjing City based on analysis of the results from 1999 to 2002. Methods The production of β-lactamase was determined by paper acidometric method. Minimum inhibitory concentrations (MICs) of penicillin, ceftriaxone, tetracycline, ciprofloxacin and spectinomycin were determined by an agar plate dilution method. Results A total of 417 clinical isolates of Neisseria gonorrhoeae were examined. During the period of 1999-2002, positive rate of PPNG rapidly increased from 8.0% to 31.31% (P<0.005). Prevalence of TRNG increased from 1.8% in 1999 to 22.2% in 2002 (P<0.005). Among non-PPNG isolates, prevalence of chromosomally mediated resistance to penicillin ranged from 64.08% to 87.80%. Positive rate of chromosomal resistance to ciprofloxacin was between 83.93% and 97.17%. There was no gonococcal isolate resistant to ceftriaxone, but the prevalence of strains less susceptible to ceftriaxone rose from 17.9% in 1999 to 50.5% in 2002. One Neisseria gonorrhoeae strain resistant to spectinomycin each was detected in 2001 and 2002. Conclusions Among Neisseria gonorrhoeae strains isolated in Nanjing City, plasmid mediated resistance (including PPNG and TRNG) has increased rapidly, and the proportions of chromosomally mediated resistance to both penicillin and ciprofloxacin are high. Spectinomycin-resistant Neisseria gonorrhoeae strain is rarely seen. Ceftriaxone and spectinomycin are considered as effective drugs for the treatment of gonorrhea.

Key words: Neisseria gonorrhoeae, Microbial sensitivity tests