Alonso Carla Andrea, González-Barrio David, Ruiz-Fons Francisco, Ruiz-Ripa Laura, Torres Carmen
Área Bioquímica y Biología Molecular, Universidad de La Rioja, 26006 Logroño, Spain.
Health and Biotechnology (SaBio) Group, Spanish Wildlife Research Institute IREC (CSIC-UCLM-JCCM), 13071 Ciudad Real, Spain.
FEMS Microbiol Ecol. 2017 Mar 1;93(3). doi: 10.1093/femsec/fix016.
Wild boars are worldwide distributed mammals which population is increasing in many regions, like the Iberian Peninsula, leading to an increased exposition to humans. They are considered reservoirs of different zoonotic pathogens and have been postulated as potential vectors of antimicrobial-resistant (AMR) bacteria. This study aimed to determine the prevalence of antimicrobial resistance and phylogenetic distribution of Escherichia coli from wild boar feces. Antimicrobial resistance and integron content was genetically characterized and E. coli of B2 phylogroup was further analyzed by molecular typing and virulence genotyping. The prevalence of AMR E. coli was low, with only 7.5% of isolates being resistant against at least one antimicrobial, mainly ampicillin, tetracycline and/or sulfonamide. An unexpected elevated rate of B2 phylogroup (47.5%) was identified, most of them showing unrelated pulsed-field-gel-electrophoresis patterns. ST131/B2 (fimH 22 sublineage), ST28/B2, ST1170/B2, ST681/B2 and ST625/B2 clones, previously described in extraintestinal infections in humans, were detected in B2 isolates, and carried one or more genes associated with extraintestinal pathogenic E. coli (ExPEC). This study demonstrated a low prevalence of antimicrobial resistance in E. coli from wild boars, although they are not exempt of AMR bacteria, and a predominance of genetically diverse B2 phylogroup, including isolates carrying ExPEC which may contribute to the spread of virulence determinants among different ecosystems.
野猪是分布于世界各地的哺乳动物，其种群数量在许多地区都在增加，如伊比利亚半岛，这导致它们与人类的接触增多。它们被认为是多种人畜共患病原体的宿主，并被假定为耐抗菌药物（AMR）细菌的潜在传播媒介。本研究旨在确定野猪粪便中大肠杆菌的耐药性流行情况及其系统发育分布。对耐药性和整合子含量进行了基因特征分析，并通过分子分型和毒力基因分型对B2系统发育群的大肠杆菌进行了进一步分析。AMR大肠杆菌的流行率较低，只有7.5%的分离株对至少一种抗菌药物耐药，主要是氨苄西林、四环素和/或磺胺类药物。发现B2系统发育群的比例意外升高（47.5%），其中大多数显示出不相关的脉冲场凝胶电泳图谱。在B2分离株中检测到先前在人类肠道外感染中描述的ST131/B2（fimH 22亚系）、ST28/B2、ST1170/B2、ST681/B2和ST625/B2克隆，并携带一个或多个与肠道外致病性大肠杆菌（ExPEC）相关的基因。本研究表明，野猪大肠杆菌的耐药性流行率较低，尽管它们并非不含AMR细菌，且遗传多样的B2系统发育群占主导地位，包括携带ExPEC的分离株，这可能有助于毒力决定因素在不同生态系统中的传播。
