广东省布鲁氏菌分离株的分子特征分析

目的了解广东省布鲁氏菌分离株的分子特征。方法应用传统分型鉴定方法和PCR扩增布鲁氏菌属特异性基因BCSP31,对广东省历年布鲁氏菌分离株作鉴定分型,进一步采用脉冲场电泳技术(PFGE)进行分子分型,分析比较菌株分子指纹图谱的相似性,以探讨不同年份和地域菌株之间的相关性。结果1965年广东省布鲁氏菌分离株以羊种和猪种为主,1985年的分离株均为猪种3型,2006和2007年的分离株均为羊种3型;PFGE电泳图谱经聚类分析结果显示,历年布鲁氏菌分离株分成三大簇(Clusters):1965年羊种、1965年猪种与1985年猪种3型、2006年和2007年羊种3型。近两年珠三角地区布鲁氏菌病的流行优势菌型为羊种3型,且同源性达100%,但与1965年羊种分离株的同源性只有77.7%。结论近两年我省布鲁氏菌的优势菌型为羊种3型,各地区分离株之间的遗传关系高度相关,与20年前的分离株同源性差。PFGE可作为传统生物分型的补充手段,可在种的水平对布鲁氏菌分离株分型。

The molecular characteristics of Brucella isolated in Guangdong province

To understand the molecular characteristics of Brucella isolated in Guangdong province,29 isolates of Brucella from 1965 to 2007 were identified by traditional methods and PCR assay,and the molecular typing was performed by pulsed-field gel elecyrophoresis(PFGE).The similarities on fingerprinting were compared through clustering analysis by using Bionumerics software.The results showed that the predominant species of Brucella in 1965,1985,2006 and 2007 were B.melitensis and B.suis biovar 3 and both B.melitensis biovar 3 respectively.As demonstrated from the clustering analysis by PFGE,all the Brucella isolated in various years in Guangdong province could be divided into these 3 clusters.The predominant species of Brucella isolated in recent 2 years was B.melitensis biovar 3 which has 100% a homology of 100% with isolates recently isolated and a 77% homology with those isolated in 1965.These data indicate that B.melitensis biovar 3 is the predominant species of Brucella circulating in the pear river area of Guangdong province with significant difference from those isolated 20 years ago.These results also reveal that PFGE is a useful tool for effective discrimination among brucella species.