佛山市食品中致泻大肠埃希菌菌型分布及毒力研究

目的 了解佛山市食品中致泻大肠埃希氏菌的菌型分布及毒力携带情况。方法采集佛山市十类食品362件中分离的17株致泻大肠埃希氏菌。按GB4789．6-94国家卫生标准检验方法进行血清分型；用ELISA检测耐热肠毒素(ST)和不耐热肠毒素(LT)；毒力测定采用小鼠致病力试验和采用irp2和irpB基因探针菌落原位杂交检测ES-IEC菌株毒力岛。结果 菌型分布在三类11个型别上，其中EPEC占41．17％(7／17)，EIEC为35．29％(6／17)。ESIEC为23．53％(4／17)；17株致泻大肠埃希氏菌在七类食品中均有存在。对小鼠致病力试验均为阳性；耐热肠毒素(ST)和不耐热肠毒素(LT)均为阴性，其中4株ESIEC中1株携带耶尔森氏菌强毒力岛(HPI)。结论佛山市食品中污染致泻大肠埃希氏菌普遍，对小鼠致病力与耐热和不耐热肠毒素无必然联系；有携带耶尔森氏菌HPI的ESIEC存在。应引起足够重视。

Study on the distribution of serotype and virulence of diarrheogenic Escherichia coli in foods in Foshan City

Objective To study the distribution of serotype and virulence detection for diarrheogenilc Escherichia coli in foods in Foshan City. Methods Seventeen strains of diarrheogenil E.coli were isolated from 362 samples in ten kinds of foods,serological assay was processed by GB4789.6-94.The ELISA method was used to detect heat-stable toxin(ST) and heat-labile(LT) detection;mice pathogenicity test was used in virulence detection;irp2 and irpB gene fragments were used as DNA probes. Results The distribution of serotype was mainly in eleven type of three kinds of germs,positive rate of EPEC;EIEC were 41.18%(7/17);35.29%(6/17);23.5%(4/17),seventeen strains of diarrheogenil E coli were found in seven of ten kinds of foods,mice pathogenicity tests were positive;ST and LT were negative.one of four strains ESICE carried Yersinia HPI. Conclusion The mice pathogericity,ST and LT tests had no relationship.It was common in Foshan that diarrheogenic E coli contaminated foods and ESIEC carrying Yersinia HPI was also found in foods.