Abstract: 【Abstract】 Objective To analyze the quality of antimicrobial susceptibility testing in laboratories at national surveillance sites for Neisseria gonorrhoeae antimicrobial resistance. Methods From 2022 to 2024, the National Center for STD Control, Chinese Center for Disease Control and Prevention annually distributed blinded proficiency testing panels to 20 national Neisseria gonorrhoeae antimicrobial resistance surveillance sites. Each panel comprised 3 coded Neisseria gonorrhoeae isolates and standard powders of 7 antimicrobial agents （penicillin, ciprofloxacin, spectinomycin, tetracycline, ceftriaxone, azithromycin, and cefixime）. Sentinel site laboratories performed antimicrobial susceptibility testing by the agar dilution method and reported the test results to the National Center for STD Control. If the minimum inhibitory concentration （MIC） of a proficiency test isolate was within ± 1 two-fold dilution of the reference MIC, the result was considered concordant, and the concordance rate was calculated accordingly. In addition, penicillinase-producing Neisseria gonorrhoeae was also tested, and the assessment results were rated according to the concordance of results across all sample tests. Results From 2022 to 2024, a total of 168 result reports were received, with an overall reporting rate of 93.3%; the numbers of participating laboratories in the above years were 19, 19, and 18, respectively; the numbers of qualified laboratories were 16 （84.2%）, 18 （94.7%） and 18 （100%）, respectively, with an overall pass rate of 92.9%. The overall 3-year concordance rates of antimicrobial susceptibility testing, in descending order, were as follows: 98.8% for spectinomycin （166 reports）, 97.0% for tetracycline （163 reports）, 89.9% for ciprofloxacin （151 reports）, 88.7% for azithromycin （149 reports）, 87.5% for penicillin （147 reports）, 85.1% for cefixime （143 reports）, and 82.7% for ceftriaxone （139 reports）; the concordance rate of plasmid-mediated high-level tetracycline resistance testing was 100.0%, and that of penicillinase-producing Neisseria gonorrhoeae testing was 96.4%. During the 3-year surveillance period, the concordance rates of penicillin, ceftriaxone, ciprofloxacin, spectinomycin, azithromycin, and cefixime testing showed an upward trend, the concordance rate of plasmid-mediated penicillinase-producing Neisseria gonorrhoeae testing showed a downward trend, and that of tetracycline testing fluctuated. Conclusion During the 3-year surveillance period, the sentinel site laboratories showed steady improvement in the quality of antimicrobial susceptibility testing for penicillin, ceftriaxone, ciprofloxacin, spectinomycin, azithromycin, and cefixime.

Key words: Neisseria gonorrhoeae, Drug resistance, Drug resistance surveillance, Drug susceptibility test, External quality assessment