Surveillance results of Neisseria gonorrhoeae resistance in sexually transmitted disease clinics in Zhejiang, 2013–2018

ObjectiveTo analyze the trend of resistance of clinical isolates of Neisseria gonorrhoeae to six antibiotics in some sexually transmitted disease (STD) clinics in Zhejiang province.

MethodsThe minimal inhibitory concentrations (MICs) of penicillin, tetracycline, ciprofloxacin, azithromycin, ceftriaxone and spectinomycin to N. gonorrhoeae were detected by agar dilution method using the isolates from STD clinics in some areas of Zhejiang from 2013 to 2018, and the plasmid mediated penicillinase producing N. gonorrhoeae (PPNG) strain was determined by paper acidity method.

ResultsA total of 672 N. gonorrhoeae strains were tested in 6 years. The detection rates of PPNG and plasmid mediated high-level plasmid mediated tetracycline-resistant N. gonorrhoea (TRNG) strains were 48.81% (328/672) and 45.09% (303/672) respectively, the annual detection rate ranged from 45.71% to 52.85% and 35.00% to 66.32% respectively, which were at a high level without significant change ( χ²＝1.372, 1.424, P＞0.05); the resistance rate to ciprofloxacin was as high as 100.00% (672/672), no sensitive strain was found. The resistance rate to azithromycin increased from 12.00% in 2013 to 28.32% in 2018, with the average of 24.26% (163/672), the change trend was significant ( χ²＝6.035, P＜0.05); the low sensitive rate to ceftriaxone was 9.08% (61/672), and the drug resistance rate to spectinomycin was 0.60% (4/672). There was a dilution increase of MIC₅₀ and MIC₉₀ respectively for both antibiotics with a significant change trend ( χ²＝18.876, 8.132, P＜0.01).

ConclusionCeftriaxone and spectinomycin are suitable for the first-line treatment of gonorrhea in some areas of Zhejiang, but the low sensitive rate to ceftriaxone is increasing year by year, and long term surveillance for dynamic change of drug resistance of N. gonorrhoeae in needed.