Department of Medicine, Division of Infectious Diseases and Immunology
Bacteria | Bacterial Infections and Mycoses | Epidemiology | Immunology of Infectious Disease | Microbiology
Azithromycin resistance (AZM-R) of Neisseria gonorrhoeae is emerging as a clinical and public health challenge. We determined molecular characteristics of recent AZM-R Nanjing gonococcal isolates and tracked the emergence of AZM-R isolates in eastern Chinese cities in recent years. A total of 384 N. gonorrhoeae isolates from Nanjing collected from 2013 to 2014 were tested for susceptibility to AZM and six additional antibiotics; all AZM-R strains were characterized genetically for resistance determinants by sequencing and were genotyped using N. gonorrhoeae multiantigen sequence typing (NG-MAST). Among the 384 isolates, 124 (32.3%) were AZM-R. High-level resistance (MIC, > /=256 mg/liter) was present in 10.4% (40/384) of isolates, all of which possessed the A2143G mutation in all four 23S rRNA alleles. Low- to mid-level resistance (MIC, 1 to 64 mg/liter) was present in 21.9% (84/384) of isolates, 59.5% of which possessed the C2599T mutation in all four 23S rRNA alleles. The 124 AZM-R isolates were distributed in 71 different NG-MAST sequence types (STs). ST1866 was the most prevalent type in high-level AZM-R (HL-AZM-R) isolates (45% [18/40]). This study, together with previous reports, revealed that the prevalence of AZM-R in N. gonorrhoeae isolates in certain eastern Chinese cities has risen > 4-fold (7% to 32%) from 2008 to 2014. The principal mechanisms of AZM resistance in recent Nanjing isolates were A2143G mutations (high-level resistance) and C2599T mutations (low- to mid-level resistance) in the 23S rRNA alleles. Characterization of NG-MAST STs and phylogenetic analysis indicated the genetic diversity of N. gonorrhoeae in Nanjing; however, ST1866 was the dominant genotype associated with HL-AZM-R isolates.
Neisseria gonorrhoeae, antimicrobial resistance, azithromycin, eastern Chinese cities, molecular epidemiology
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Copyright © 2018 Wan et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
DOI of Published Version
Antimicrob Agents Chemother. 2018 Apr 26;62(5). pii: e02499-17. doi: 10.1128/AAC.02499-17. Print 2018 May. Link to article on publisher's site
Antimicrobial agents and chemotherapy
Wan, Chuan; Li, Yang; Le, Wen-Jing; Liu, Yu-Rong; Li, Sai; Wang, Bao-Xi; Rice, Peter A.; and Su, Xiao-Hong, "Increasing Resistance to Azithromycin in Neisseria gonorrhoeae in Eastern Chinese Cities: Resistance Mechanisms and Genetic Diversity among Isolates from Nanjing" (2018). Open Access Articles. 3432.
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This work is licensed under a Creative Commons Attribution 4.0 License.