猪水肿病致病性大肠杆菌的分离与血清型鉴定

为确定四川某猪场流行的大肠杆菌病血清型,以便为研制大肠杆菌灭活疫苗提供相对应的菌株,从本场25～40日龄病死仔猪和腹泻仔猪的肝、脾、小肠及粪便与直肠拭子中,分离出48株致病性大肠杆菌,根据血清型鉴定结果,共有9个血清型,其中O138、O139、O141最常见,致病力较强,O139分离率最高,为41.46%,并且自猪源分离到具有致病性的E.coliO157,说明猪体内携带有该菌,可通过食物链传染给人类,这在公共卫生学上具有重要意义,应引起高度重视. 药敏结果表明,所分离大肠杆菌对丁胺卡那霉素、氧氟沙星、培氟沙星、环丙沙星的抑菌作用最强,高敏菌株达75%～96%;氯霉素、新霉素、庆大霉素、恩诺沙星敏感度居中,敏感菌株在50%～60%之间;青霉素、痢特灵、强力霉素、磺胺-5-甲氧嘧啶抑菌作用较低,敏感菌株低于20%.

The Isolation and Serotype Identification of Piglet Escherichia Coli

In order to detect the serotype and antibiotics sensitivity of piglet Escherichia coli, we picked 48 stains of E. coli from the piglets, livers, the spleens, the small intestines, the dejectas and the rectal swabs in the hogpen. The results of stereotyping showed that there were 9 serotypes in the isolated E. coli, among which, O138, O139, and O141 had high pathogenicity to mice. O139 was predominant, the mean isolation percentage in piglet was 41.6%. In the same way, we picked O157 which had pathogencity from the hogpen, it showed that the piglets were carrying this type of bacteria and would infect human through the food chain, and that it had the great meaning in the sanitary science, which should attract our attention. The results of antibiotics sensitivity showed that most of the isolated E. coli had high sensitivity to Amikacinum, Ofloxacin, Pefloxacin and Ciprofloxacin, of which the sensitive strains were 75%-96% medium sensitivity to Chlomycetin, Gentamin, Neomycin Sulfas, of which the sensitive strains were about 50%-60%; low sensitivity to Penicillinum, Doxycyclinum, Furazolidonum, Sulfame thoxydiazi- num of which the sensitive strains were under 20%.