Abstract: Objective To reveal the biological characteristics of E. coli isolated from experimental rabbits with diarrhea. Method The genetic lineage, antibiotic sensitivity, disinfectant sensitivity, drug resistance gene and virulence related gene of the pathogenic Escherichia coli strain isolated from SPF rabbits died of diarrhea were studied comprehensively. Result The Escherichia coli strain belonged to B1 type genetic lineage, and carried the virulence gene eaeA, which was the classic virulence genes of enteropathogenic Escherichia coli (EPEC) . In addition, this isolated strain was sensitive to 5 commonly used disinfectants. Besides, it was resistant to 11 antibiotics including penicillin, ampicillin, cephalexin, cephradine, tetracycline, doxycycline, minocycline, erythromycin, midecamycin, vancomycin and cotrimoxazole, and carried 4 drug resistance genes, including aadA1, gyrA, sul1 and tetA. Conclusion The pathogenic Escherichia coli strain isolated from SPF rabbits died of diarrhea is a type B1 genetic pedigree EPEC with multiple drug resistance and it is sensitive to common disinfectants.

Key words: EPEC, drug resistance, virulence gene, diarrhea

摘要： 目的 研究从腹泻实验兔分离到的大肠埃希菌的生物学特性。 方法 对一株从因腹泻而死亡的 SPF 级实验 兔体内分离的致病性大肠埃希菌的遗传谱系、抗生素敏感性、消毒液敏感性以及细菌携带的耐药基因和毒力基因进行较为全面的研究。 结果 该大肠埃希菌属于 B1 型遗传谱系,携带毒力基因 eaeA,属于肠致病性大肠埃希菌。 对常用的 5 种消毒液敏感,对于青霉素、氨苄西林、头孢氨苄、头孢拉定、四环素、多西环素、米诺霉素、红霉素、麦迪 霉素、万古霉素、复方新诺明等 11 种抗生素耐药,携带 aadA1,gyrA,sul1 和 tetA 等 4 个抗生素耐药基因。 结论 从 因腹泻而死亡的 SPF 级实验兔体内分离的致病性大肠埃希菌为一株 B1 型遗传谱系的肠致病性大肠埃希菌,具有 多重耐药性,对常用的消毒剂均敏感。

关键词: 肠致病性大肠埃希菌, 耐药性, 毒力基因, 腹泻