1Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
2Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran.
J Med Microbiol. 2018 Sep;67(9):1334-1339. doi: 10.1099/jmm.0.000786. Epub 2018 Jul 3.
Entero-aggregative Escherichia coli (EAEC) is one of the main causes of diarrhoea worldwide. Several virulence factors have been identified in EAEC. This study was conducted to investigate the distribution of virulence factor genes in EAEC strains isolated in Iran from children with diarrhoea, as well as the genetic similarity of these isolates.
A total of 37 EAEC isolates were tested for the presence of 11 virulence genes by PCR, and the genetic relatedness of these strains was further determined by multilocus variable-number tandem-repeat analysis (MLVA).
All EAEC isolates were typical EAEC. pic, set1A and set1B were the most prevalent genes, detected in 54.1 % of the isolates, followed by sat (43.2 %), astA (32.4 %), pet (24.3 %), agg4A (24.3 %), sepA (18.9 %), agg3A (13.5 %), sigA (8.1 %), aggA (8.1 %) and aafA (5.4 %). Using MLVA, the 37 isolates were divided into 32 types and classified into five clonal complexes.
This study showed that EAEC is a heterogeneous group of E. coli possessing a broad range of virulence factors. There was no notable association between MLVA patterns and virulence profiles.
肠聚集性大肠杆菌（EAEC）是全球腹泻的主要病因之一。已鉴定出 EAEC 的几种毒力因子。本研究旨在调查从伊朗腹泻儿童中分离的 EAEC 菌株中毒力因子基因的分布，以及这些分离株的遗传相似性。
通过 PCR 检测 37 株 EAEC 分离株中 11 种毒力基因的存在情况，并进一步通过多位点可变数串联重复分析（MLVA）确定这些菌株的遗传相关性。
所有 EAEC 分离株均为典型的 EAEC。pic、set1A 和 set1B 是最常见的基因，在 54.1%的分离株中检测到，其次是 sat（43.2%）、astA（32.4%）、pet（24.3%）、agg4A（24.3%）、sepA（18.9%）、agg3A（13.5%）、sigA（8.1%）、aggA（8.1%）和 aafA（5.4%）。通过 MLVA，37 株分离株分为 32 种类型，并分为 5 个克隆复合体。
本研究表明，EAEC 是一组具有广泛毒力因子的异质性大肠杆菌。MLVA 模式与毒力谱之间没有明显的关联。
