Department of Veterinary Laboratory Technology, College of Agriculture and Natural Resource, Debre Markos University, Debre Markos, Ethiopia.
School of Animal Science and Veterinary Medicine, College of Agriculture and Environmental Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
PLoS One. 2022 Sep 28;17(9):e0275229. doi: 10.1371/journal.pone.0275229. eCollection 2022.
Diarrheagenic Escherichia coli strains are an essential cause of diarrheal infection in younger children and animals. The study was focused on understanding the associated characteristics of various DEC strains among children and calves, establishing the possible zoonotic transmission, and determining their antibiotic resistance patterns. Samples from 144 acute diarrheic children and 50 diarrheic calves were collected and processed using traditional culture methods. The molecular identification of pathotypes was completed using primer-specific polymerase chain reaction (PCR) targeting ten virulence genes (stx1, stx2, eae, aatA, lt, st, ial, hlyA bfpA, and daaE) related to six DEC pathotypes (EPEC, ETEC, EHEC, EAEC EIEC, and DAEC). The antimicrobial susceptibility testing was carried out using the Kirby-Bauer disk diffusion method. Colonies from 74 study subjects (54 diarrheic children and 20 diarrheic calves) were positive for E. coli isolates. Subsequent PCR detection discovered that 77% of children and 85% of calves' isolates were positive for one or more virulence genes typical of particular strains. Among those ETEC [(18%), (26%)] is being the maximum predominant, and [(15%), (15%)] were positive for STEC, [(13%), (8%)] for atypical EPEC, [(6%), (7%)] for EHEC, [(6%), (5%)] for EAEC, and [(6%), (4%)] for EIEC strains in children's and calves, respectively. Of the identified E. coli isolates, about 29% were found to be hybrid isolates. ETEC (66.7%) and STEC (58.9%) strains showed a better detection rate in contact children with diarrheic calves than children with no contacts. Most antibiotic resistances were obtained towards amoxicillin (64.9%), gentamycin (56.8%), and ampicillin (54.1%). Up to sixty-five percent of isolates were resistant to a minimum of three categories of antibiotics. This is the primary report on the wide occurrence of the six-diarrheagenic Escherichia coli strains, and ETEC was found to be the predominant pathotype among children and contact calves in Ethiopia.
肠致病性大肠杆菌菌株是导致婴幼儿和动物腹泻感染的重要原因。本研究旨在了解儿童和犊牛中各种 DEC 菌株的相关特征，确定可能的人畜共患病传播途径，并确定其抗生素耐药模式。采集了 144 名急性腹泻儿童和 50 名腹泻犊牛的样本，采用传统培养方法进行处理。采用针对十个与六种 DEC 血清型（EPEC、ETEC、EHEC、EAEC、EIEC 和 DAEC）相关的毒力基因（stx1、stx2、eae、aatA、lt、st、ial、hlyA、bfpA 和 daaE）的引物特异性聚合酶链反应（PCR）对病原菌进行分子鉴定。采用 Kirby-Bauer 纸片扩散法进行抗生素药敏试验。从 74 名研究对象（54 名腹泻儿童和 20 名腹泻犊牛）的粪便中分离出大肠杆菌。随后的 PCR 检测发现，77%的儿童和 85%的犊牛分离株携带一种或多种特定菌株的毒力基因。其中，ETEC（18%、26%）是最多的优势菌，STEC（15%、15%）阳性，非典型 EPEC（13%、13%）阳性，EHEC（6%、6%）阳性，EAEC（6%、5%）阳性，EIEC（6%、4%）阳性。在儿童和犊牛中，分离的大肠杆菌中约有 29%为混合分离株。与无接触儿童相比，与腹泻犊牛接触的儿童中，ETEC（66.7%）和 STEC（58.9%）的检出率较高。大多数抗生素耐药性发生在氨苄西林（64.9%）、庆大霉素（56.8%）和氨苄西林（54.1%）。高达 65%的分离株至少对三类抗生素耐药。这是关于六种肠致病性大肠杆菌菌株广泛流行的首次报道，在埃塞俄比亚，ETEC 是儿童和接触犊牛的主要血清型。
