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-135 variants, 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 bla TEM-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.
ABSTRACT
Objective To determine Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST) sequence types in different geographical areas of China,including Changzhou and Yangzhou cities of Jiangsu province,Wuzhou and Hezhou cities in Guangxi Zhuang Autonomous region,Sanya and Qionghai cities of Hainan province,Jiangmen and Maoming cities of Guangdong province.Methods DNA was extracted using Qiagen DX extraction kits from 88 urine samples which were collected from male patients attending sexually transmitted disease (STD) clinics and positive for nucleic acid amplification test (NAAT) for N.gonorrhoeae.Two rounds of PCR were carried out to amplify the porB and tbpB genes of N.gonorrhoeae followed by gene sequencing.Sequence alignment was performed on the NG-MAST website (http://www.ng-mast.net) to determine the genotype of N.gonorrhoeae.Results The first-round PCR yielded positive results for porB and tbpB in 13.6％ (12/88) and 14.8％ (13/88),respectively,of these urine specimens,and 12 samples were successfully genotyped with the efficiency of genotyping being 13.6％.The amplification efficiency of second-round PCR was enhanced to 71.6％ and 72.7％ for porB and tbpB,respectively,and the efficiency of genotyping increased to 70.5％ (62/88).Compared with the first-round PCR,the second-round PCR showed an increase in amplification efficiency for porB and tbpB by 58.0％ and 57.9％ respectively,as well as in genotyping efficiency by 56.9％.Forty-five genotypes were identified in the 62 samples,including 40 known genotypes and 5 novel genotypes.Of these genotypes,ST1866 was the most abundant (6/62),followed by ST1972 (4/62) and ST3356 (4/62),all of which were from Jiangsu province.The ST532 genotype was identified in 3 samples from Guangdong province,ST2221 genotype in 2 samples from Guangxi Zhuang Autonomous region.Each of the remaining genotypes was identified in only 1 sample and scattered in all of these cities.The 5 novel MAST-genotypes were as follows:porB-892 and tbpB-46 (98％ similarity),porB-130 and tbpB-504 (96％ similarity),porB-2790 and tbpB-32 (99％ similarity),porB-1053 and tbpB-856 (99％ similarity).Conclusions Urine samples can be used for NG-MAST analysis,and two rounds of PCR can enhance the efficiency of genotyping.NG-MAST genotypes appear to be diverse in different geographical areas of China.
ABSTRACT
Objective To compare the potentiality of opa typing versus Neisseria gonorrhoeae multi-antigen sequence typing (Ng-MAST) in discrimination of N. gonorrhoeae isolates, and to investigate the consistency of genotypes of N. gonorrhoeae between patients and their sex partners. Methods N. gonor-rhoeae was isolated from patients and their sex partners who attended sexually transmitted disease clinics of the Affiliated Union Hospital of Tongji Medical College, Huazhong University of Science and Technology from February 2006 to August 2007. All isolates were cultured on Thayer-Martin agar and GC-based choco-late agar, and identified by Gram stain and oxidase reaction. Totally, twenty-four strains of N. gonorrhoeae were isolated form 12 pairs of male-female sex partners. Genomic DNA was isolated from the strains, and subjected to PCR amplification of opa gene as well as pot and tbpB genes, opa typing and Ng-MAST typing were utilized to differentiate the 24 strains respectively. Results The 24 isolates were classified into 10 sequence types (ST) by Ng-MAST typing, and 12 opa types (OT) by opa typing. A novel genotype identi-fied by Ng-MAST (217-86% homologisation 178), was unique in China. Conclusions Both ST and OT of N. gonorrhoeae strains are identical between patients and their corresponding partners except for one pair of partners, 45/46, suggesting that gonorrhea is transmitted to each other by contiguity between sex partners. Opa typing is likely to be more potential than Ng-MAST in genotyping of N.gonorrhoeae strains.