陕西省布鲁氏菌分离株MLVA分型研究

目的 对陕西省1952—2019年以来保存的布鲁氏菌分离株进行MLVA分型研究，了解陕西省布鲁氏菌遗传变异情况,为制定预防控制策略提供依据。方法 基于MLVA技术对收集的121株布鲁氏菌分离株基因型进行研究，利用Bio Numerics 7.6软件进行聚类分析，计算辛普森指数。结果 基于MLVA-8分型，分为7种，即羊种菌5种（42、43、63、83及115型），猪种菌1种（6型）及牛种菌1种（38型），其中羊种42、43型占总数的91.74%；42型在全省10个市区均有分布；榆林、延安均有4种基因型，多样性较其他市区更丰富；基于MLVA-11，分为11种，基于MLVA-16对121株菌种进行聚类分析结果显示，所有菌株分为3个群，96个基因型，呈现基因型别的多样性，辛普森指数在0.000～0.800之间，Panel 1和Panel 2A多样性均明显低于Panel 2B。结论 MLVA技术可用于种属亲缘关系的确立、菌株遗传多样性分析以及分子流行病学溯源调查,陕西省布鲁氏菌MLVA分型显示高度基因多态性，提示陕西省布病流行呈零星和散发特征, 因此,降低传染源在区域之间的频繁流动，是控制布病疫情发生的有效手段。

Study on MLVA genotyping of Brucella in Shaanxi

Objective To understand the epidemic variation of Brucella in Shaanxi Province.]Methods Based on MLVA-8 and MLVA-16, the genotype and regional distribution of 121 Brucella isolates were studied, and Bio Numerics 7.6 was used for cluster analysis and then calculated Simpson Index.]Results Based on MLVA-8 typing, there were 7 species, 5 species of B.melitensis (42, 43, 63, 83 and 115 types), 1 species of B.suis (6 types) and 1 species of B.abortus (38 types), of which B.melitensis (42, 43 types) accounted for 91.74%. Type 42 was distributed in 10 cities, and there were 4 genotypes in Yulin and Yan’an City. Based on MLVA-11, there were 11 kinds. The results of cluster analysis of 121 strains based on MLVA-16 showed that all strains could be divided into 3 groups and 96 genotypes. The Simpson index ranged from 0.000 to 0.800. Panel 1 and Panel 2A were significantly lower than Panel 2B.]Conclusion The MLVA technique can be used to establish the genetic relationship of species, analyze the genetic diversity of strains and trace the source of molecular epidemiology. The MLVA typing of Brucella in Shaanxi Province shows a high degree of polymorphism. It is suggested that the epidemic of Brucellosis in Shaanxi Province is sporadic. Therefore, reducing the frequent flow of infectious sources between regions is an effective means to control brucellosis epidemic.