新疆牛源E.coli O157:H7的致病力及PFGE分子分型

Pathogenicitytest and PFGE typing of bovine origin Escherichia coli O157:H7 in Yili and Akesu

对2012-2015年新疆8株牛源E.coli O157:H7进行毒性强弱测定和PFGE分子分型。结果显示,几乎所有菌株能使小鼠出现精神沉郁、食欲减退、腹泻等症状,且3株导致小鼠死亡。病理组织学检查发现,死亡小鼠的肝、脾、肾等组织器官均表现较明显的病理损伤。8株E.coli O157:H7 PFGE图谱相似性为74.3%~100%。经聚类分析得到A-C共3类基因簇,其中优势基因簇为B。E.coli O157:H7在两地区具有水平传播途径。

In order to study the pathogenicity of bovine origin E.coli O157:H7,and the intrinsic relationship among different isolates.Eight strains of bovine E.coli O157:H7 collected in Xinjiang from 2012 to 2015 were evaluated for toxicity and PFGE molecular typing.It was found that 5 strains carried at least one virulence gene.Almost all isolates can make infected mice display depression,anorexia,diarrhea and other symptoms,and 3 of them eventually killed the mice.Histopathological examination revealed that liver,spleen,kidney and other tissues and organs of the dead mice all had obvious pathological lesions.PFGE spectrum similarity of the 8 strains was between 74.3%and 100%,and A to C,3 PFGE types were obtained through cluster analysis,B was the dominant types.E.coli O157:H7 may have clonal propagation in cattle farms,and there may be cross-regional transmission.There was horizontal transmission path with E.coli O157:H7 in different areas.