商丘市、济源市腹泻患者、家禽、家畜粪便中E.coli O157:H7的鉴定

目的：对商丘市、济源市腹泻患者、家禽、家畜粪便中首次分离的E.coliO157:H7进行生物学特性等方面的研究。方法：采集疫区患者，外环境，家畜和家禽粪便标本1895份，采用mEC肉汤增菌，胶体金免疫卡快速测定法，免疫磁珠集菌法，CHROMAGAR-O157：H7菌株，在CHROMAGAR-O157：H7显色培养基生长形态，颜色，生化反应出现多样化，rfbO157,stx2,hlyA,eaeA基因检测均阳性的有58株，stx2阳性1株，eaeA阳性4株，72株无毒力基因。结论：为本省实验室诊断E.coliO157:H7提供了理论依据；不同种类的家禽，家畜分离的产毒菌株比例差别显著，以波尔山羊最为突出；为今后在制定对该菌的诊断标准，传染源的追踪和控制及细菌毒力学等方面的研究提供了重要线索。

Study on E.coli O157:H7 strains isolated from feces of patients with diarrhea, domestic animals and poultry in Shangqiu and Jiyuan Cities

Aim:To study the biological characterization of E.coli O157:H7 that firstly isolated from feces from patients, domestic animals and poultry in the diarrhea epidemic areas of Shangqiu city and Jiyuan city.Methods:Samples collected from patients, domestic animals, and poultry were isolated with mEC broth enrichment, immunomagnetic separation (IMS), and CHROMAGAR O157 medium isolation. Virulence factors of isolated strains were detected with muti PCR assays. Results:A total of 137 E.coli O157:H7 strains were isolated. All of them showed different colors and figures on CHROMAGAR O157 medium, and appeared contrary reactions in biochemical tests. A total of 58 of them were positive for rfbO157, Shiga toxin type 2(stx2), enterohemolysin(encoded by EHEC hlyA), and intimin (encoded by eaeA) . one strain was positive for stx2, 4 were positive for eaeA, and 72 were negative for virulence factors.Conclusion:The study offers the data for determination of E.coli O157:H7 strains in laboratory. The rate of producing virulence factors show significant difference in strains isolated from different breeds of domestic animals and poultry, especially in breed of Bohr goat. The study is very helpful to determination of E.coli O157:H7 bacteria, survey and control of pathogeny and contamination resources and research at bacterial toxicology.