Detection of Escherichia coli O157:H7 in heifers' faecal samples using an automated immunoconcentration system
Detection of Escherichia coli O157:H7 in heifers' faecal samples using an automated immunoconcentration system
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使用自动免疫浓缩系统检测小母牛粪便样本中的大肠杆菌 O157:H7
DOI：
10.1046/j.1472-765x.2000.00702.x
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发表时间：
2000
影响因子：
2.4
通讯作者：
V. Atrache
中科院分区：
文献类型：
--
作者：
C. Vernozy;P. Feng;M. Montet;S. Ray‐Gueniot;L. Villard;C. Bavai;A. Meyrand;C. Mazuy;V. Atrache
用自动免疫浓缩（ICE）系统预处理5小时的富集培养，大大提高了从母牛粪便样品中分离出大肠杆菌O157:H7。富集样品直接镀在山梨糖醇麦康基琼脂（SMAC）和添加头孢克肟和碲酸钾（CT‐SMAC）的SMAC琼脂上，回收率分别为8%和56%。然而，经过ICE处理后，大肠杆菌O157:H7在SMAC上的回收率为92%，在CT - SMAC上的回收率为100%。1998年3月至6月期间，对从法国一家屠宰场收集的小母牛粪便样本进行免疫浓度分析，结果显示1%（300头中有3头）的O157:H7大肠杆菌呈阳性。表型和基因型分析表明，3株分离株均携带O157和H7抗原，不发酵山梨醇或具有β -葡萄糖醛酸酶活性，并携带大肠杆菌O157:H7的性状毒力因子（uidA等位基因、eaeA和pO157质粒）。然而，只有一个菌株是产毒的，这个菌株产生单一的毒素，即verotoxin 2。
Pre‐treatment of a 5‐h enrichment culture with an automated immunoconcentration (ICE) system greatly improved the isolation of Escherichia coli O157:H7 from spiked heifer faecal samples. Enrichment samples plated directly onto sorbitol MacConkey agar (SMAC) and SMAC agar supplemented with cefixime and potassium tellurite (CT‐SMAC) showed recovery rates of 8% and 56%, respectively. However, after ICE treatment, E. coli O157:H7 was recovered from 92% of the samples on SMAC and 100% on CT‐SMAC. Immunoconcentration analysis of heifers' faecal samples collected from a slaughter‐house in France, during March to June 1998, showed that 1% (three of 300) was positive for E. coli O157:H7. Phenotypic and genotypic analysis showed that all three isolates carried both the O157 and H7 antigens, did not ferment sorbitol or had β‐glucuronidase activity and carried trait virulence factors for E. coli O157:H7 (uidA allele, eaeA and pO157 plasmid). However, only one strain was toxigenic and this strain produced a single toxin, namely verotoxin 2.