Evidence for a human-specific Escherichia coli clone
Evidence for a human-specific Escherichia coli clone
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DOI：
10.1111/j.1462-2920.2007.01520.x
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发表时间：
2008-04-01
影响因子：
5.1
通讯作者：
Denamur, Erick
中科院分区：
文献类型：
--
作者：
Clermont, Olivier;Lescat, Mathilde;Denamur, Erick
大肠杆菌是一种广泛存在于脊椎动物肠道的共生菌。直到最近，还没有发现特定克隆与特定宿主物种之间的强烈联系。然而，具有O81血清型的B2亚型VIII克隆的成员似乎是人类宿主特异性的。为了确定该克隆所表现出的宿主特异性程度，采用基于pcr的方法筛选了723株人类粪便和临床分离株以及904株动物粪便分离株。在动物分离株中未发现这种克隆，但在非洲、欧洲和南美洲的人群中发现了这种克隆。这种克隆很少从患有肠道或肠外疾病的人身上分离出来，在肠外感染的小鼠模型中是无毒的。精细流行病学分析表明，该克隆相对于B2系统发育类群的其他成员具有竞争性优势，并且在过去20年中出现频率有所增加。该克隆似乎是用作益生菌的良好候选者，并且可能适合作为微生物来源跟踪研究中人类粪便污染的指标。
Escherichia coli is a widespread commensal of the vertebrate intestinal tract. Until recently, no strong association between a particular clone and a given host species has been found. However, members of the B2 subgroup VIII clone with an O81 serotype appear to be human host specific. To determine the degree of host specificity exhibited by this clone, a PCR-based assay was used to screen 723 faecal and clinical isolates from humans, and 904 faecal isolates from animals. This clone was not detected among the animal isolates, but was discovered in people living in Africa, Europe and South America. The clone is rarely isolated from people suffering from intestinal or extraintestinal disease and is avirulent in a mouse model of extraintestinal infection. Fine-scale epidemiological analysis suggests that this clone is competitively dominant relative to other members of the B2 phylogenetic group and that it has increased in frequency over the past 20 years. This clone appears to be a good candidate for use as a probiotic, and may be suitable as an indicator of human faecal contamination in microbial source tracking studies.