Penicillinase-producing Neisseria gonorrhoeae and its blaTEM-135 gene variants at several gonococcal antimicrobial surveillance sites in China: an epidemiological study

Abstract

Objective To determine the prevalence of penicillinase-producing Neisseria gonorrhoeae(PPNG) and the distribution of blaTEM-135 gene variants in PPNG at several gonococcal antimicrobial surveillance sites in China, to compare N. gonorrhoeae multi-antigen sequence typing (NG-MAST) types of PPNG and its blaTEM-135 gene variants, and to assess the difference and association in NG-MAST types of blaTEM-135 gene variants among different regions. Methods A total of 572 N. gonorrhoeae isolates were collected at 6 gonococcal antimicrobial surveillance sites from Jiangsu, Shanghai, Zhejiang, Tianjin, Guangdong and Guangxi in 2012. After isolation, purification, and identification, cefalotin paper discs were used for detection of PPNG. DNA was extracted by QIAxtractor DX kits after cultivation of the PPNG strains. Then, mismatch amplification mutation assay (MAMA) PCR was performed to identify blaTEM-135variants, and NG-MAST analysis to determine N. gonorrhoeae genotypes. Results Among the 572 N. gonorrhoeae strains, 38.1%(218/572) were identified as PPNG, and of the PPNG strains, 52.3%(114/218) were blaTEM-135 variants. The detection rate of PPNG at these surveillance sites from high to low was as follows: 51.7%(45/87, Zhejiang), 45.6%(36/79, Shanghai), 38.0%(78/205, Guangdong), 37.5%(12/32, Guangxi), 31.2%(24/77, Jiangsu) and 25.0%(23/92, Tianjin), and that of blaTEM-135 variants was as follows: 68.9%(31/45, Zhejiang), 58.3%(14/24, Jiangsu), 50.0%(39/78, Guangdong), 47.2%(17/36, Shanghai), 39.1%(9/23, Tianjin) and 33.3%(4/12, Guangxi). NG-MAST analysis showed that the ST2318, ST1768, ST1866, ST1053 and ST8726 types predominated among these blaTEM-135 variants, and a strong correlation was found between blaTEM-135 variants and some NG-MAST types, such as ST1768, ST1053 and ST8726 types. The distribution of NG-MAST types was significantly different between the surveillance site in Tianjin (in the Northern part of China) and the other sites (in the Southern part of China), but highly similar among the surveillance sites in Jiangsu, Zhejiang and Shanghai regions. Conclusions There is a high prevalence of PPNG and its blaTEM-135 variants at several gonococcal antimicrobial surveillance sites in China, with significant differences in NG-MAST genotype distribution of PPNG and its blaTEM-135 variants among different regions. Key words: Neisseria gonorrhoeae; beta-Lactamases; Epidemiology; blaTEM-135 Gene variant; Neisseria gonorrhoeae multi-antigen sequence typing