Abstract

Healthy animals can constitute a reservoir for Escherichia coli potentially dangerous for humans. Our objectives were to investigate virulence genes in E. coli isolated from healthy animals in southern Tunisia and to determine their resistance to antimicrobials of high importance in humans and animals. 126 fecal samples were collected from healthy animals (cattle, sheep, goats, chicken, camel, bustard and rabbit) and assayed by PCR for virulence genes and by disk diffusion for antimicrobial resistance. STEC were isolated most frequently from goats (27.7%), sheep (20%) and cattle (14.2%). ExPEC prevalence of iucD (41.6%), papC (27.7%), sfa (13.8%), afa8 (13.8%) and iron (72.2%) was highest in camels. Prevalence of the ExPEC associated genes iss and cnf and the EPEC defining gene eae was highest in rabbits (53.3, 13.3, and 53.3%, respectively). The genes defining enterotoxigenic, enteroinvasive and enteroaggregative E. coli were not detected and faeG was found only in camels (5.5%). The most common phylogenetic groups were B1 (54.5%) and B2 (16.6%). Virulence gene profiles varied greatly between animal species. Overall, antimicrobial resistance was not highly prevalent, the highest resistance being observed against tetracycline, 43.9%.

摘要

健康的动物可以构成对人类有潜在危险的大肠杆菌的储存库。我们的目标是调查从突尼斯南部健康动物中分离出来的大肠杆菌中的毒力基因，并确定它们对人类和动物中非常重要的抗菌素的耐药性。从健康动物（牛、绵羊、山羊、鸡、骆驼、鸨和兔）收集了 126 份粪便样本，并通过 PCR 检测毒力基因和通过圆盘扩散检测抗菌素耐药性。STEC 最常从山羊 (27.7%)、绵羊 (20%) 和牛 (14.2%) 中分离出来。的ExPEC能患病IUCD（41.6％），PAPC（27.7％），SFA（13.8％），afa8（13.8％）和铁(72.2%) 在骆驼中最高。ExPEC 相关基因iss和cnf以及 EPEC 定义基因eae 的患病率在兔子中最高（分别为 53.3、13.3和 53.3%）。未检测到定义产肠毒素、肠侵袭性和肠聚集性大肠杆菌的基因，仅在骆驼中发现了faeG (5.5%)。最常见的系统发育组是 B1 (54.5%) 和 B2 (16.6%)。动物物种之间的毒力基因谱差异很大。总体而言，抗菌素耐药性并不十分普遍，对四环素的耐药性最高，为 43.9%。