Resistance Mechanisms and Molecular Epidemiology of Neisseria gonorrhoeae with Low Susceptibility/Resistance to Azithromycin or Cephalosporins

Sucai Chen,1 Fangyuan Xia2 1Clinical Laboratory Department, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, People’s Republic of China; 2Department of Pharmacy, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, People’s Republic of ChinaCorrespondence: Fangyuan Xia, Department of Pharmacy, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, Zhejiang, People’s Republic of China, Tel +86 13736716291, Email [email protected]: To investigate the resistance patterns of Neisseria gonorrhoeae strains with low susceptibility or resistance to azithromycin or ceftriaxone in the Wenzhou region from 2021 to 2023, as well as their resistance to other antibiotics and their Neisseria gonorrhoeae multi-antigen sequencing and typing (NG-MAST) genotypes.Patients and Methods: A total of 212 Neisseria gonorrhoeae isolates collected from 2021 to 2023 were subjected to agar dilution testing to determine the minimum inhibitory concentrations (MIC) for penicillin, tetracycline, ciprofloxacin, azithromycin, ceftriaxone, and Daquanmycin. Identification of Penicillinase -Producing Neisseria gonorrhoeae (PPNG) Strains Mediated by Plasmids Using the Paper Strip Acidity Assay and perform Neisseria gonorrhoeae multi-antigen sequencing typing (NG-MAST).Results: Among the 212 Neisseria gonorrhoeae isolates tested, 27 (12.74%) exhibited azithromycin resistance. Eight strains (3.77%) showed low susceptibility or resistance to ceftriaxone. Among the 27 azithromycin-resistant Neisseria gonorrhoeae strains, the detection rates for PPNG and plasmid-mediated highly tetracycline-resistant Neisseria gonorrhoeae (TRNG) were 81.48% (22/27) and 33.33% (9/27), respectively. NG-MAST typing revealed that the 27 azithromycin-resistant strains primarily included ST5061 (n = 7), ST1866 (n = 2), ST4183 (n = 2), ST14504 (n = 1), ST9659 (n = 1), and ST12196 (n = 1). All 8 ceftriaxone low-susceptibility/resistant strains were ST1866 (n=3).Conclusion: The prevalence of low susceptibility/resistance to ceftriaxone among Neisseria gonorrhoeae strains in Wenzhou remains low, but long-term surveillance is still necessary, particularly among young and middle-aged adults. NG-MAST typing can serve as a molecular biological marker for monitoring gonococcal resistance.Plain Language Summary: 1. This study detected low-sensitivity/drug-resistant strains resistant to azithromycin and cephalosporins for the first time. This study was the first report of ST typing in this region, which is of great significance to the study of drug-resistant gonococcus in this region. 2. This study also showed that only one strain was resistant to both azithromycin and ceftriaxone, which was the first detection of azithromycin and cephalosporins low sensitivity/drug resistance strains in this region, which is of great significance. 3. Our findings provide a scientific basis for rational and optimized antibiotic use in clinical practice, helping to delay the emergence of resistant bacteria and combat the threat of antibiotic resistance.Keywords: Neisseria gonorrhoeae, azithromycin, ceftriaxone, NG-MAST, genotype