犊牛腹泻源大肠杆菌生物被膜形成相关基因检测及菌株致病力测定

Detection of biofilm-associated genes and pathogenicity of Escherichia coli isolated from calves with diarrhea

利用PCR技术检测25株犊牛腹泻源大肠杆菌的生物被膜形成相关基因,并通过动物试验测定了菌株的致病力,分析生物被膜形成相关基因与菌株致病力的关系。结果显示:flu在所检测25株菌中出现的频率最高,占68%;其次是ropS和fimA,分别占44%和40%;espA占24%;fliC占10%。6株生物被膜阳性菌株的动物攻毒试验显示,其致病力明显强于生物被膜阴性菌株,且含有3种或3种以上待测基因。本试验为探讨生物被膜与大肠杆菌致病性的关系提供一定的基础。

PCR was used to detect the biofilm formation related genes of 25 strains of Escherichia coli from calves with diarrhea,and their pathogenicity was determined by animal experiment. The results showed that the frequency of flu in the 25 strains was the highest,accounting for 68%,followed by fim A and rop S,accounting for 44% and 40%,esp A accounted for 24%,and fli C accounted for 10%. The animal test of 6 strains positive for biofilm showed that their virulence were higher than the negative strains for biofilm,and the six bacterial strains contained 3 or more than 3 tested genes. This experiment provides a basis for investigation of the relationship between the biofilm and the pathogenicity of E. coli.