PDF(Pubmed)
Abstract：
Extraintestinal pathogenic Escherichia coli (ExPEC) strains are capable of causing various systemic infections in both humans and animals. In this study, we isolated and characterized 30 E. coli strains from the parenchymatic organs and brains of young (<3 months of age) camel calves which died in septicemia. Six of the strains showed hypermucoviscous phenotype. Based on minimum inhibitory concentration (MIC) values, seven of the strains were potentially multidrug resistant, with two additional showing colistin resistance. Four strains showed mixed pathotypes, as they carried characteristic virulence genes for intestinal pathotypes of E. coli: three strains carried cnf1, encoding cytotoxic necrotizing factor type 1, the key virulence gene of necrotoxigenic E. coli (NTEC), and one carried eae encoding intimin, the key virulence gene of enteropathogenic E. coli (EPEC). An investigation of the integration sites of pathogenicity islands (PAIs) and the presence of prophage-related sequences showed that the strains carry diverse arrays of mobile genetic elements, which may contribute to their antimicrobial resistance and virulence patterns. Our work is the first to describe ExPEC strains from camels, and points to their veterinary pathogenic as well as zoonotic potential in this important domestic animal.
摘要：
肠外致病性大肠杆菌（ExPEC）菌株能够在人和动物中引起各种全身性感染。在这项研究中,我们从死于败血症的幼年（<3月龄）骆驼小牛的实质器官和大脑中分离并鉴定了30株大肠杆菌。其中6株表现出高粘膜粘性表型。基于最小抑制浓度（MIC）值，其中7株具有潜在的多重耐药性，另外两个显示粘菌素抗性。四个菌株表现出混合的病理类型，因为它们携带了大肠杆菌肠道致病型的特征性毒力基因:三株携带cnf1，编码细胞毒性坏死性因子1型，这是坏死性大肠杆菌(NTEC)的关键毒力基因，一个携带eae编码内膜蛋白，肠致病性大肠杆菌(EPEC)的关键毒力基因。对致病性岛（PAIs）的整合位点和与噬菌体相关的序列的存在的调查表明，这些菌株携带不同的可移动遗传元件阵列，这可能有助于他们的抗菌素耐药性和毒力模式。我们的工作是第一个描述来自骆驼的ExPEC菌株，并指出了这种重要的家畜的兽医学致病性和人畜共患潜力。
