【摘要】 运用生化鉴定及大肠杆菌基因保守序列对引起奶牛乳腺炎的大肠杆菌进行分离鉴定,通过ERIC-PCR、RAPD以及大肠杆菌种类进化群判定标准对其进行种系分群,应用SPSS 17.0软件对ERIC-PCR及RAPD扩增图谱进行聚类分析,探讨不同地区分离的大肠杆菌之间的基因相似性。结果显示,共分离出大肠杆菌13株,根据种系进化群判定标准,该地区A群占61.54%,D群占44.4%,B2群占7.69%。聚类分析显示,ERIC-PCR体系将13株大肠杆菌分为3个聚类群,Ⅰ型7株(占53.85%),Ⅱ型4株(占30.77%),Ⅲ型2株(占15.38%),其中青海省民和县80%的菌株属于Ⅰ型,甘肃省永登县、临洮县及青海省民和县71.43%的菌株属于Ⅱ型和Ⅲ型。RAPD体系将13株大肠杆菌分为2个聚类群,Ⅰ型7株(占53.85%),Ⅱ型6株(占46.15%),其中宁夏区吴忠市的菌株属于Ⅰ型,甘肃省永登县、临洮县及青海省民和县的菌株属于Ⅱ型。基因相似性研究结果显示,以甘肃省兰州市为中心,位于东北方向的宁夏区吴忠市与西南方向的其他3个地区分离菌株的基因相似性存在一定的差异。更多还原

【Abstract】 Escherichia coli were isolated and characterized by biochemical analysis and its housekeeping sequence.Sequence profile gained by ERIC-PCR and RAPD method were statistically analysed with cluster analysis in SPSS 17.0,to evaluate the genetic similarity of the isolated E.coli from different areas.In result,13 strains of E.coli were isolated from the samples.According to the gel maps and phyletic evolution analysis,group A was 61.54%,group D was 44.4%,group B2 was 7.69%.And the 13 strains of E.coli would also be categoried into three groups by cluster analysis,7 strains in typeⅠ(53.85%),4 strainsin typeⅡ(30.77%) and 2 strains in typeⅢ(15.38).Eigthy percent strains isolated from Qinghai belongs to typeⅠ,while 71.43% strains from other three areas belongs to typeⅡ and typeⅢ.When using the RAPD grouping system,all the 13 strains are grouped into two groups,typeⅠ 7 stains(53.85%) and typeⅡ 6 strains(46.15%),and 80% strains isolated from Qinghai belongs to typeⅠ,while other 83.3% isolates from other three places belongs to typeⅡ.Genetic similarity showed that the E.coli isolated from Qinghai,are genetically,to some degree,different from the E.coli isolated from other three places located in southwest of Lanzhou.更多还原