MLVA基因分型方法研究世界多地区布鲁氏菌的流行病学特征

目的 通过多位点串联重复序列分析（MLVA）研究世界多国家和地区分离的布鲁氏菌分子流行病学特征。方法 选择11个可变数目串联重复序列位点，使用BioNumerics软件，采用非加权配对算术平均法，对1953－2013年全球48个国家和地区分离的布鲁氏菌VNTR资料进行聚类分析，绘制系统发育树和最小生成树，分析菌株的流行分布特征。结果 布鲁氏菌系统发育树的进化关系与经典的生物分型方法基本上吻合，但猪种生物5型菌株与其他猪种生物1、2、3和4型菌株关系较远；鲸种布鲁氏菌也分为2个部分，并且关系较远。2005－2008年出现了全球布鲁氏菌病（布病）流行，中国是布病多发区，主要流行株为羊种布鲁氏菌，其次是牛种布鲁氏菌，猪种布鲁氏菌主要出现在中国南部省份，犬种布鲁氏菌只在犬中出现，人类没有发现病例。结论 布鲁氏菌具有种的系统发育树特征，并且具有分离的时间、地域和宿主的特异性，这些特征对于布病的防控具有重要意义。

Epidemiological characteristics of Brucella species isolated from different regions of the world using the MLVA genotyping

Objective To study the molecular-epidemiological characteristics of Brucella species isolated from different countries, using the multiple locus tandem-repeat (MLVA) analysis. Methods Eleven variable-number tandem-repeat (VNTR) loci were selected. VNTR strains of Brucella isolated from 48 different countries in 1953-2013, were analyzed by using the BioNumerics software. Unweighted Paired Arithmetic Average method was used to cluster and draw phylogenetic tree as well as the minimum spannin. Results The evolutionary relationship of Brucella phylogenetic tree was consistent with the classical biological typing method. However, the Brucella suis biovar 5 strains were different from the other Brucella suis biovars 1, 2, 3 and 4. Brucella ceti strains were divided into two parts and different from each other. Worldwide epidemics of brucellosis were emerged from 2005 to 2008 under the MLVA11 Orsay analysis. China has been a brucellosis-prone regions, with Brucella melitensis as the main epidemic Brucella species, followed by Brucella abortus. Brucella suis was mainly identified in the southern provinces, but Brucella canis was mainly found in dogs. No human cases were found. Conclusion Molecular-epidemiological characteristics of the Brucella strains were related to factors as time, region and hosts of isolation, which are important to setting up prevention and control programs on brucellosis.