| 摘要: |
| 【目的】对陕西省致仔猪腹泻产肠毒素大肠埃希菌（Enterotoxigenic E.coli,ETEC）的肠毒素及黏附素进行分子流行病学调查。【方法】采集陕西省陕北（子洲、甘泉）、陕南（汉中、城固）和关中（杨凌、西安、户县）3个地区7个大型养猪场1～50日龄腹泻仔猪的粪便样品，进行大肠埃希菌的分离与鉴定。采用普通和多重PCR方法，检测已知能表达毒素的大肠埃希菌标准菌株，以验证试验方法的可行性；采用多重PCR方法，对分离自陕西省腹泻仔猪粪便样品中的大肠埃希菌进行肠毒素（STa、STb、LT）和黏附素（K88、K99、987P、F41）检测。【结果】试验共分离鉴定出104株大肠埃希菌，其中表达肠毒素的菌株有45株，STa、STb、LT和STa+LT阳性的菌株数量分别为28，5，8和4株；表达黏附素的共31株，K88、K99、987P和K88+987P阳性的菌株分别为4，22，2和3株。在被检测的样品中，同时表达肠毒素和黏附素的大肠埃希菌有14株；陕南地区仅检测出STa肠毒素和K99黏附素，陕北地区较复杂，各毒素类型均有出现。在1～7日龄，致仔猪腹泻大肠埃希菌表达的毒素主要是K99和STa；到20～30日龄时，各种毒素均有不同程度检出。【结论】陕西省致仔猪腹泻ETEC表达的肠毒素主要是STa，表达的黏附素主要是K99；毒力因子的分布与区域和仔猪日龄有密切关系。 |
| 关键词: 陕西省 ETEC 分子流行病学 |
| DOI： |
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| 基金项目:西北农林科技大学引进人才科研启动经费项目（01140409） |
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| A molecular epidemiological investigation on piglets diarrhea induced by ETEC in Shaanxi Province |
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| Abstract: |
| 【Objective】A molecular epidemiological investigation on piglets diarrhea induced by Enterotoxigenic E.coli was performed in Shaanxi Province.【Method】Isolation and identification of E.coli were performed from stool samples of 1-50-day-old piglet diarrhea collected from 7 pig farms in Northern Shaanxi Province Area(Zizhou,Ganquan),Southern Area (Hanzhong,Chenggu) and Guanzhong Area(Yangling,Xi’an,Huxian).The standard strains E.coli containing a known toxin were detected by using the ordinary and multi PCR to verify the feasibility of testing;The enterotoxin（STa,STb,LT） and adhesion（K88,K99,987P,F41）were detected respectively by multiplex PCR from Escherichia coli of formerlly isolates.【Result】The separation and identification of 104 E.coli showed that harbored enterotoxin had a total of 45,STa,STb,LT,and STa＋LT number of gene positive strains were 28,5,8 and 4 respectively.Adhesion that harbored in Escherichia coli had a total of 31,including K88,K99,987P and K88+987P,whose positive strains were 4,22,2 and 3 strains respectively.A total of 14 samples having expressions of toxin and adhesin were detected in all samples at the same time.Only STa enterotoxin and K99 adhesin in the southern region of Shaanxi Province were detected.In northern Shaanxi Province,the toxin types appeared.The harbored toxins in 1-7-day-old piglets were mainly K99 and STa;Various toxin genes of the 20-30-day-old in detection were detected.【Conclusion】The main enterotoxin and adhesion of ETEC inducing piglets diarrhea in Shaanxi Province were STa and K99.The distribution of virulence factors was closely related to the region and the day age of piglets. |
| Key words: Shaanxi Province ETEC molecular epidemiologrl |
