Askari Badouei Mahdi, Jajarmi Maziar, Mirsalehian Akbar
Department of Pathobiology, Faculty of Veterinary Medicine, Garmsar Branch, Islamic Azad University, Garmsar, Iran.
Department of Pathobiology, Faculty of Veterinary Medicine, Garmsar Branch, Islamic Azad University, Garmsar, Iran.
Comp Immunol Microbiol Infect Dis. 2015 Feb;38:15-20. doi: 10.1016/j.cimid.2014.11.005. Epub 2014 Dec 4.
In the present study the occurrence, genotypic characteristics and relatedness of Shiga toxin-producing Escherichia coli (STEC) isolated from 235 fecal samples of diarrheic children (n=75), sheep (n=80), and cattle (n=80) were investigated. Overall, STEC was found in 4%, 61.2%, and 18.7% of diarrheic children, sheep and cattle, respectively. Three of the four STEC isolates from diarrheic children yielded the stx1/ehly profile. The predominant virulence profile of sheep isolates was stx1/ehly (85.2%), but cattle isolates were heterogeneous. Genetic relatedness and diversity of 36 selected isolates were analyzed by enterobacterial repetitive consensus sequences fingerprinting (ERIC) and phylogrouping. In total, 19 ERIC-types were observed in humans (n=2), sheep (n=5), and cattle (n=12) isolates. The majority of the sheep STEC were assigned into B1 phylogroup (83.3%), but cattle isolates belonged to different phylogroups with B1 predominance. Three human STEC isolates had the major characteristics of sheep isolates but revealed distinct fingerprint. These findings indicate that cattle can potentially carry a diverse group of STEC strains.
在本研究中，对从腹泻儿童（n = 75）、绵羊（n = 80）和牛（n = 80）的235份粪便样本中分离出的产志贺毒素大肠杆菌（STEC）的发生情况、基因型特征及亲缘关系进行了调查。总体而言，腹泻儿童、绵羊和牛中STEC的检出率分别为4%、61.2%和18.7%。腹泻儿童分离出的4株STEC中有3株呈现stx1/ehly谱型。绵羊分离株的主要毒力谱型为stx1/ehly（85.2%），但牛分离株具有异质性。通过肠杆菌重复一致序列指纹图谱（ERIC）和系统发育分组分析了36株选定分离株的遗传亲缘关系和多样性。在人类（n = 2）、绵羊（n = 5）和牛（n = 12）分离株中总共观察到19种ERIC型。大多数绵羊STEC被归入B1系统发育群（83.3%），但牛分离株属于不同的系统发育群，以B1为主。3株人类STEC分离株具有绵羊分离株的主要特征，但显示出不同的指纹图谱。这些发现表明，牛可能携带多种不同的STEC菌株。
