来自腹泻合并急性肾衰病人疫区的99株E.coli O157∶H7的鉴定结果分析

目的调查研究河南省2000年3月17日-7月6日发生的腹泻合并急性肾衰病人的致病菌。方法采集病人、外环境、家畜和家禽标本620份,采用免疫磁珠集菌法、CHROMAGAR-O157∶H7显色培养基分离及营养肉汤增菌、rfbO157、rfbO111引物多重PCR扩增等方法进行病原菌的检测。结果分离出99份E.coli O157∶H7菌株,其中rfbO157、志贺氏样毒素2(stx2)、溶血素(hlyA)、肠上皮细胞纤毛消除素(eaeA)基因和vero细胞毒性试验均阳性的有56株,其它基因组合7株,36株无毒力基因。结论99株E.coli O157∶H7在CHROMAGAR-O157∶H7显色培养基生长形态、颜色,生化反应及毒力基因表现等方面出现多样化,对于今后在制定对该菌的诊断标准、传染源的控制及细菌毒力学等方面的研究提供了依据。

Determination on 99 E. coli O157:H7 Strains from the Epidemic Area with Patients of Diarrhea and Hemolytic - Uraemic Syndrome

Objective Investigate and research for pathogenic bacteria causing diarrhea and hemolytic uraemic syndrome (HUS) in Henan Province from 17 March to 6 Huly 2000.Methods 620 samples collected from patients,domestic animals and poultry were tested with Mec broth enrichment,immunomagnetic separation IMS] , CHROMagarO157 medium isolation and rfbO157 and rfbO111 primers muti - PCR.Results 99 E.coli O157:H7 strains are isolated.56 of them were positive for rfbO157.Shiga toxin type 2(stx2)、enterohemolysin (encoded by CHEC hlyA)、intimin (encoded by eaeA) and Verocytotoxins virulence test. 7 stains can produce less virulence factors.36 of them were neg-ative for virulence factors. Conclusions The tests showed that 99 e.coli O157:H7 strains had various colon shapes and colors on CHROMagar - O157 medium,and different biochemical reaction as well as viruience factors. This study is helpful for determination on bacteria,control of contamination resources and research at bacterial toxicology.