四川省嗜肺军团菌血清Ⅰ型(LP1)基因分型研究

目的为了解四川省嗜肺军团菌(Legionella pneumophila,LP)基因特征,采用多位点串联重复序列分析(MLVA)和基因序列分型(SBT)两种方法对四川省1989—2016年分离到的42株嗜肺军团菌血清I型(LP1)进行基因分型研究。方法根据文献报道的军团菌8个VNTR位点和SBT 7个管家基因对42株嗜肺军团1型菌(LP1)分别进行PCR扩增。VNTR结果经毛细管电泳分析后,得到MLVA分型。SBT结果测序后上传至欧洲军团菌感染组(EWGLI)数据库得到ST分型。结果 42株嗜肺军团菌血清I型(LP1)分为8个MLVA型,优势型别为M08型(47.6%)和M07型(23.8%)。SBT分为12个ST型,其中有2个ST型(ST2359,ST2360)为首次发现。ST1(52.3%)、ST630(14.2%)为优势型别。12个ST型分为3个克隆群(Clonal Complex,CCs)和2个singleton。结论 MLVA方法和SBT方法均能用于LP1型分子流行病学监测及分子遗传学特征的研究。四川省LP1型具备较高的遗传多样性和地区特异性,有感染人的风险,应加强对公共卫生环境中军团菌的监测工作。

Gene typing of Legionella pneumophila serogroup 1 in Sichuan Province,China

The aim of the research is to investigate the genetic characteristics of Legionella pneumophila serogroup1 (LP1)in Sichuan Province.The sequence-based typing (SBT) and multiple-locus VNTR analysis (MLVA) were used to describe the genetic polymorphism of 42 strains which were isolated from 1989-2016 in Sichuan Province,China.According to the reference,PCR was used to detect the 8-VNTR loci and 7 housekeeping genes respectively.The VNTR results were determined by using capillary electrophoresis,and the SBT results were sequenced and compared with the database of EWGLI.Results showed that totally 42 stains were divided into 8 MLVA types with the advantage types were M08 (47.6 ％) and M07 (23.8 ％).Twelve ST types were obtained with 3 main clonal complex and 2 singleton,including 2 novel ST types,among those,ST1 was the predominant type,accounting for 52.3 ％,following by ST630 (14.2 ％).In conclusion,our results demonstrated MLVA and SBT were both applied to the research for molecular epidemiological investigation of LP1 and showed the high genetic polymorphism and the regional specificity.The results also suggest that the isolates are a potential threat to the public,effective control and prevention strategies are urgently needed.