2012年东台市肠出血性大肠埃希菌O157︰H7监测分析

Analysis of enterohemorrhagic Escherichia coli O157︰H7 surveillance data in Dongtai City in 2012

目的了解肠出血性大肠埃希菌O157︰H7在东台市动物宿主和腹泻患者中带菌及毒力基因携带与耐药情况。方法于流行季节采集动物宿主、腹泻患者粪便及生熟食品和苍蝇标本,mEC肉汤增菌后,用特异性免疫磁珠集菌、科玛嘉显色平板分离,纯化的菌株经生化鉴定,血清分型,以K-B纸片法进行药敏试验,采用PCR方法检测uida基因和stx1、stx2、eaeA、hly等4种毒力基因。结果 683份标本共检出O157︰H7菌株35株,检出率为5.12%,其中动物粪便检出率为10.59%(34/321),检出率最高的为牛粪(26.92%),其次为山羊粪(7.50%)和猪粪(7.32%),腹泻患者的检出率为0.39%(1/256)。35株菌株均检出eaeA和hly毒力基因,而牛粪中stx2、eaeA和hly等3种毒力基因组合型检出率达12.82%。35株菌株对氨苄西林敏感率为14.3%,对其余17种抗生素敏感率均>90%。结论东台市动物宿主和腹泻患者均不同程度携带肠出血性大肠埃希菌O157︰H7,且存在流行的潜在危险。

Objective To understand the presence and virulence genes of enterohemorrhagic Escherichia coil （EHEC） O157 ： H7 in host animals and diarrhea patients in Dongtai City, and to understand its drug resistance. Methods l）ur ing the EHEC O157 ： H7 infective period in Dongtai, Animal and diarrhea patient stool samples, various pood samples and fly samples were collected in surveillance spots in 2012. The samples were respectively cultured in mEc brolh, amassed with immunomagnetic sepanation, and isolated in CHROMAGAR O157 ： H7 culture medium. Purified isolalcs were biochemically identified, serotyped. The drug susceptibility was tested by K-B method. The uida gene and the viru lenee genes of stxl, stx2, eaeA and hly were detected by PCR. Results 35 strains of EHEC O157 ： H7 were separa ted from 683 samples （5.12%）. The detection rate in animal stool samples was 10.59%（34/321） （26.92% for cows,7. 50% for gosts and 7.32%o for pigs） ; meanwhile the rate of diarrhea patients was 0. 39%. PCR results showed that eaeA and hly were positive in all isolates, but it was 12. 82% that stx2, eaeA and hly in cows stool samples. 35 stains sensitive to ampicillin was 14.3% ,on the remaining 17 species of antibiotic susceptibility rates were greater than 90%.