Contrepois M, Dubourguier H C, Parodi A L, Girardeau J P, Ollier J L
Vet Microbiol. 1986 Jul;12(2):109-18. doi: 10.1016/0378-1135(86)90073-8.
Three strains of Escherichia coli with a common surface antigen, 31a, capable of adhering to calf enterocytes in vitro were compared to reference strains of septicaemic E. coli (RVC 330 and vir E. coli). The surface antigen 31a was present in the RVC 330 reference strain. E. coli vir had a surface antigen which was not present in E. coli 31a or E. coli RVC 330. The RVC 330 and vir reference strains also adhered to calf enterocytes in vitro. Oral infection of calves not receiving colostrum with E. coli 31a was generally followed by septicaemia and death in less than 48 h. Post-mortem examination revealed pneumonia and oedema of the kidneys and gall bladder. Oral infection of calves receiving colostrum had no effect, but intravenous inoculation produced arthritis within 15 days. The comparison of these results with those previously described by other workers did not lead to the identification of pathognomonic characteristics, which could be clearly correlated with properties specific to E. coli 31a. It is suggested that, like ColV and vir, antigen 31a may be a virulence marker for certain strains of bovine septicaemic E. coli. Furthermore, the 31a antigen appears to be carried on a plasmid.
对三株具有共同表面抗原31a且能够在体外黏附犊牛肠上皮细胞的大肠杆菌，与败血性大肠杆菌参考菌株（RVC 330和致病毒性大肠杆菌）进行了比较。表面抗原31a存在于RVC 330参考菌株中。致病毒性大肠杆菌有一种表面抗原，该抗原在31a大肠杆菌或RVC 330大肠杆菌中不存在。RVC 330和致病毒性参考菌株在体外也能黏附犊牛肠上皮细胞。用31a大肠杆菌对未摄入初乳的犊牛进行口服感染，通常在不到48小时内就会引发败血症并导致死亡。尸检显示有肺炎以及肾脏和胆囊水肿。对摄入初乳的犊牛进行口服感染没有影响，但静脉接种在15天内会引发关节炎。将这些结果与其他研究人员先前描述的结果进行比较，并未发现能够明确与31a大肠杆菌特异性特性相关的特征性特征。有人提出，与ColV和致病毒素一样，抗原31a可能是某些牛败血性大肠杆菌菌株的毒力标志物。此外，31a抗原似乎携带在质粒上。
