Fakih I, Thiry D, Duprez J-N, Saulmont M, Iguchi A, Piérard D, Jouant L, Daube G, Ogura Y, Hayashi T, Taminiau B, Mainil J G
Bacteriology, Infectious Disease Department, Institute for Fundamental and Applied Research in Animal Health (FARAH) and Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
Association Régionale de Santé et d'Identification Animale (ARSIA), 5590 Ciney, Belgium.
Vet Microbiol. 2017 Apr;202:16-22. doi: 10.1016/j.vetmic.2016.02.017. Epub 2016 Feb 23.
Escherichia coli producing Shiga toxins (Stx) and the attaching-effacing (AE) lesion (AE-STEC) are responsible for (bloody) diarrhoea in humans and calves while the enteropathogenic E. coli (EPEC) producing the AE lesion only cause non-bloody diarrhoea in all mammals. The purpose of this study was (i) to identify the pathotypes of enterohaemolysin-producing E. coli isolated between 2009 and 2013 on EHLY agar from less than 2 month-old diarrhoeic calves with a triplex PCR targeting the stx1, stx2, eae virulence genes; (ii) to serotype the positive isolates with PCR targeting the genes coding for ten most frequent and pathogenic human and calf STEC O serogroups; and (iii) to compare the MLSTypes and virulotypes of calf and human O5 AE-STEC after Whole Genome Sequencing using two server databases (www.genomicepidemiology.org). Of 233 isolates, 206 were triplex PCR-positive: 119 AE-STEC (58%), 78 EPEC (38%) and 9 STEC (4%); and the stx1+eae+ AE-STEC (49.5%) were the most frequent. Of them, 120 isolates (84% of AE-STEC, 23% of EPEC, 22% of STEC) tested positive with one O serogroup PCR: 57 for O26 (47.5%), 36 for O111 (30%), 10 for O103 (8%) and 8 for O5 (7%) serogroups. The analysis of the draft sequences of 15 O5 AE-STEC could not identify any difference correlated to the host. As a conclusion, (i) the AE-STEC associated with diarrhoea in young calves still belong to the same serogroups as previously (O5, O26, O111) but the O103 serogroup may be emerging, (ii) the O5 AE-STEC from calves and humans are genetically similar.
产生志贺毒素（Stx）并形成紧密黏附性损伤（AE损伤）的大肠杆菌（AE-STEC）可导致人类和犊牛出现（血性）腹泻，而仅产生AE损伤的肠致病性大肠杆菌（EPEC）只会在所有哺乳动物中引起非血性腹泻。本研究的目的是：（i）通过针对stx1、stx2、eae毒力基因的三重PCR，鉴定2009年至2013年间从2月龄以下腹泻犊牛的EHLY琼脂平板上分离出的产肠溶血素大肠杆菌的致病型；（ii）通过针对编码十种最常见且具有致病性的人类和犊牛STEC O血清群的基因进行PCR，对阳性分离株进行血清分型；（iii）使用两个服务器数据库（www.genomicepidemiology.org）对全基因组测序后的犊牛和人类O5 AE-STEC的多位点序列类型（MLSTypes）和毒力型进行比较。在233株分离株中，206株三重PCR呈阳性：119株AE-STEC（58%）、78株EPEC（38%）和9株STEC（4%）；stx1+eae+ AE-STEC（49.5%）最为常见。其中，120株分离株（占AE-STEC的84%、EPEC的23%、STEC的22%）通过一种O血清群PCR检测呈阳性：O26血清群57株（47.5%）、O111血清群36株（30%）、O103血清群10株（8%）和O5血清群8株（7%）。对15株O5 AE-STEC的草图序列分析未发现与宿主相关的任何差异。综上所述，（i）与幼龄犊牛腹泻相关的AE-STEC仍属于与之前相同的血清群（O5、O26、O111），但O103血清群可能正在出现，（ii）来自犊牛和人类的O5 AE-STEC在基因上相似。
