多位点序列分型在新疆人间布鲁氏菌病临床分离株遗传进化研究中的应用

目的 探讨多位点序列分型(MLST)技术在新疆人间布鲁氏菌病分离株遗传进化研究中的应用价值,了解分离株的种群结构和遗传进化关系。方法 采用MLST对2015、2016年分离自新疆7个地州的24株人间布鲁氏菌病分离株和3株布鲁氏菌标准参考菌株进行分析,统计各菌株序列型(STs),运用BioNumerics软件构建菌株最小进化树,分析菌株间遗传关系;收集过往研究的186株全国不同地区布鲁氏菌分离株MLST结果,分析各ST型分布特点。结果 24株人间布鲁氏菌分离株全部为ST8型,3株标准参考菌株(羊种16M、牛种544A、猪种1330S)分别为ST7型、ST1型、ST14型;24株人间布鲁氏菌分离株的9个MLST位点变异完全相同,分离株种群结构单一。ST8型菌是我国主要流行的布鲁氏菌,且以北方流行为主;MLST能较好的区分布鲁氏菌种别,但不能有效区分生物型别。结论 ST8型菌(羊种3型)是新疆人间布鲁氏菌病的主要流行菌株,MLST技术可作为人间布鲁氏菌种群结构和遗传进化关系研究的补充手段。

Application of Multi-locus sequence typing in the genetic evolution of Brucella clinical strains isolated in Xinjiang

The aims of our study is to investigate the application of Multi-locus sequence typing in the genetic evolution of clinical Brucella strains isolated and understand the population structure and genetic evolution of isolated strains. A total 24 strains from 7 prefectures of Xinjiang in 2015, 2016 and 3 standard reference strains were analyzed by MLST to determine sequences types, BioNumerics was used to constructed minimum spanning tree of isolated strains. We collected the MLST results of 186 strains from different provinces in refer to the former research in order to analysis on distribution features of STs. Results showed that 24 strains of Brecella clinical isolated were all ST8, 3 standard reference strains were ST7,ST1,ST14, respectively. The results showed that 9 MLST loci of 24 strains were exactly the same, and the populaion structure of isolated strains was single. The MLST results of 186 strains showed that ST8 type was prevalent in China and most populations of north. The MLST method could not be used to differentiate biotype of Brucella. In conclusion, the sequence type of ST8 is prevalent in Xinjiang, MLST is only a supplementary method for species construction and evolutionary research of Brucella.