摘要
为了从基因水平鉴定鸡源鲍氏志贺菌,分别根据GenBank中登陆的相应序列针对16S rRNA、gyrB、grpE、re-cA 4基因设计4对引物,用PCR扩增出鸡源鲍氏志贺菌4基因的部分片段并进行了克隆测序。将所获序列与Gen-Bank中同源性较高的相关序列相比较,计算种间相似性,并构建志贺菌的系统发育树,对分离株进行分类与鉴定。研究发现,从4基因的序列分析结果总体上可知鸡源志贺菌与人鲍氏志贺菌同源关系最近,同源性达99.6%～100%。几乎所有志贺菌均落入大肠杆菌的分支中,且在鉴别细菌中recA基因和gyrB基因比传统中常用的16SrRNA基因差异更显著。由此证明用细菌分类和鉴定的"金标准"16SrRNA联合gyrB、grpE、recA3个基因进行序列分析来鉴定志贺菌是一种可靠、成本较低的方法;由上述基因序列构建的系统发育树提示,该株鸡源志贺菌可能是与人志贺菌密切相关的新种或是它们的亚种。
The sequences of 16S rDNA, gyrB, grpE, recA of Shigella were analysed for the farther identification of newly found Shigella boydii strain isolated from chicken and the evolutionary position of the new strain was determined. Part of 16S rRNA and other three genes were amplified by polymerase chain reaction （PCR） from one identified Shigella boydii strains isolated from chicken and the PCR products were cloned and sequenced. These sequences obtained in this study were compared with the related sequneces reported in GenBank by software of DNA analyses. The similarity were gained and phylogenetic tree were constructed. Further evolutionary relationships among chicken Shigella boydii and other related strains were examined based on sequences. Shigella boydii isolated from chicken had the nearest homogeneity with Shigella boydii isolated from human and their homogeneity is 99.6 %-100 %. Shigella boydii isolated from chicken was in a small cluster with Shigella boydii isolated from human in four phylogenetic trees,and almost all Shigella strains are distributed among E. coli strains. Genes recA and gyrB shown a greater evolutionary divergence than 16S rRNA genes. Sequence analysis of 16S rDNA and gyrB,grpE, recA may be a reliable, rapid and low costs way for identification of Shigella strains. The homogeneity and the phylogenetic tree constructed by these four genes above revealed that the Shigella strain isolated from chicken may be a new species or subspecies of Shigella boydii.
出处
《中国兽医学报》
CAS
CSCD
北大核心
2011年第7期983-989,共7页
Chinese Journal of Veterinary Science
基金
国家自然科学基金资助项目(30671555)
