Molecular characteristics of cephalosporins resistant Neisseria gonorrhoeae strains isolated from Gonococcal Antimicrobial Resistance Surveillance Program in China, 2015-2016

Background: An increasing level of antimicrobial resistance to extended-spectrum cephalosporins (ESCs), has been reported by the China Gonococcal Antimicrobial Resistance Surveillance Program (China-GRSP). Methods: 2038 Neisseria gonorrhoeae (NG) isolates were collected from China-GRSP between 2015 and 2016. NG multiantigen sequence typing (NG-MAST), MLST (multi-locus sequence typing) and NG sequence typing for antimicrobial resistance (NG-STAR) were used to determine characteristics and resistant determinants of cephalosporins resistant isolates. Results: 74 (3.6%) cephalosporins resistant isolates were confirmed. MLSTST7363 was the most prevalent MLST among cefixime resistant (CFX-R) isolates, while MLSTST7365 (n = 8) in ceftriaxone resistant (CRO-R) isolates. And CFX-R strains mainly associated with penA-X(n = 27,44.3%), penA-XIII (n = 6,9.8%), penA-XVIII (n = 5, 8.2%), and CRO-R strains mainly related to penA-XVIII (n = 10,25.6%), penA-43(n = 9,23.1%), penA-XIII(n = 7,17.9%). Conclusion: The main conclusion of this study is that the predominant cephalosporin-resistant clones in China include locally emerged and imported linages. The CFX-R and CRO-R strains are primarily related to penA mutations and their predominant genotypes are different. With the increase of international travel, tracking high-risk resistant clones and identifying outbreaks and their association with epidemiological characteristics are critical to improve public health.