鸭疫里默杆菌重庆、四川地区分离株ompA基因的遗传变异性

Genetic variation of the ompAgenes of Riemerella anatipestifer isolated from ducklings in Chongiqng and Sichuan

为研究鸭疫里默杆菌(R.anatipestifer)外膜蛋白A(OmpA)的遗传变异性,探讨与R.anatipestifer的血清型分类间的关系,对R.anatipestifer重庆、四川地区分离株进行了生化鉴定、16SrRNA基因和OmpA的遗传多样性分析。结果显示,除DY1210株不液化明胶及DZ1212株和JJ1212株水解七叶苷外,其他分离株生化特征均一致。R.anatipestifer所有分离菌株16SrRNA基因序列相似性达99%以上,均属于同一簇。ompA基因序列分3个基因群(Ⅰ群7株、Ⅱ群8株、Ⅲ群1株),其编码氨基酸序列分3个簇(Ⅰ簇8株、Ⅱ簇7株、Ⅲ簇1株),且不同血清型菌株属于同一基因群或氨基酸簇,同一血清型属于不同的基因群或氨基酸簇。结果表明,R.anatipestifer所有分离菌株ompA所属基因群或氨基酸簇与其血清型没有明显的联系。

Genetic diversity of the ompAgene of Riemerella anatipestifer(R.anatipestifer)isolated from Ducklings or gooses in Chongiqng and Sichuan were investigated to explore the relationship between the OmpAand serotype or infectious spectrum of R.anatipestifer.The biochemical properties of R.anatipestifer strains were tested,16S rRNA and OmpAgene-based PCR was able to amplify all strains.The results showed that each strain has approximate biochemical properties except for DY1210 strain which can liquefaction gelatin,DZ1212 and JJ1212 strain can hydrolysis esculin.The identity of 16S rRNA sequence of all isolates was more than 99%,and phylogenetic analysis based on the 16SrRNA gene showed that all the R.anatipestifer strains fell into a single cluster.The percentage identity of the ompA sequence of the all strains amplified in this study was96.5%-99.8%.Phylogenetic tree analysis of the ompA nucleotide sequences clustered the R.anatipestifer strains into three genegroups(genegroup Ⅰ contained 7strains,genegroup Ⅱ contained 8strains,and genegroupⅢcontained one strains),and three clusters were found when the derived amino acid sequence was the basis of analysis.It is concluded that no apparent cluster was found using the criteria of isolate serotype among all isolates.