3株非典型羊源布鲁菌的基因分型研究

目的]探讨采用基因分型方法对非典型布鲁菌鉴定的实用性,为非典型菌株的鉴别提供参考。方法]采用常规鉴定方法和VITEK 2.0全自动细菌鉴定分析系统对菌株进行初步鉴定,利用AMOS-PCR进行种型鉴定,应用多位点可变数目串联重复序列分析方法(MLVA)确定菌株的基因型。结果]常规鉴定结果显示试验菌株为疑似布鲁菌;VITEK 2.0全自动细菌鉴定系统显示3株试验菌株均为布鲁菌;AMOS-PCR扩增表明试验菌株均为羊种菌,MLVA聚类分析表明试验菌株与羊种2型布鲁菌紧密地聚为一类,属东地中海基因型,并在Panel 2B中发现了新的基因型(4-4-3-7-5),命名为CN2B-45。结论]MLVA基因分型方法对非典型布鲁菌具有极高的分辨力,是非典型布鲁菌分型鉴别的最佳策略。

Characterization of the Genotype of Three Clinically Isolated Atypical Brucella Strains from Sheep

Objective]To verify the practicability of genotyping method for the confirmation of atypical Brucella strains, and to provide reference for the discriminative identification of the atypical ones. Method]The both conventional identification methods and VITEK 2. 0 automatic bacteria identification analysis system were used to carry out the preliminary identification of the clinical Brucella strains from sheep. AMOS-PCR was applied to discriminate the species of the strains. The genotype of the tested strains were determined by using MLVA assay. Result]Conventional identification results showed that the three tested isolates were Brucella-suspected strains; VITEK 2. 0 automatic bacteria identification analysis system confirmed that the tested strains all belonged to Brucella genus; AMOS-PCR amplification showed that the strains were Brucella melitensis(B. melitensis); MLVA cluster analysis revealed that the tested strains were close with B. melitensis biovar 2 and belonged to Eastern Mediterranean lineages; a new genotype (4-4-3-7-5) was found in the Panel 2B and was designated as CN2B-45. Conclusion]MLVA assay has excellent discriminative power for atypical Brucella strain and is the best strategy for identification of atypical Brucella strain.