School of Public Health, University of Alberta, Edmonton, AB, Canada.
Antimicrobial Resistance-One Health Consortium, Calgary, AB, Canada.
Sci Rep. 2024 Jun 12;14(1):13478. doi: 10.1038/s41598-024-64241-y.
The Escherichia coli species is comprised of several 'ecotypes' inhabiting a wide range of host and natural environmental niches. Recent studies have suggested that novel naturalized ecotypes have emerged across wastewater treatment plants and meat processing facilities. Phylogenetic and multilocus sequence typing analyses clustered naturalized wastewater and meat plant E. coli strains into two main monophyletic clusters corresponding to the ST635 and ST399 sequence types, with several serotypes identified by serotyping, potentially representing distinct lineages that have naturalized across wastewater treatment plants and meat processing facilities. This evidence, taken alongside ecotype prediction analyses that distinguished the naturalized strains from their host-associated counterparts, suggests these strains may collectively represent a novel ecotype that has recently emerged across food- and water-associated engineered environments. Interestingly, pan-genomic analyses revealed that the naturalized strains exhibited an abundance of biofilm formation, defense, and disinfection-related stress resistance genes, but lacked various virulence and colonization genes, indicating that their naturalization has come at the cost of fitness in the original host environment.
大肠杆菌物种由几种“生态型”组成，栖息在广泛的宿主和自然环境小生境中。最近的研究表明，新型归化生态型已经出现在废水处理厂和肉类加工厂。系统发育和多位点序列分型分析将归化的废水和肉类加工厂大肠杆菌菌株聚类为两个主要的单系群，分别对应 ST635 和 ST399 序列类型，通过血清分型鉴定出几种血清型，可能代表已经归化到废水处理厂和肉类加工厂的不同谱系。这一证据，加上生态型预测分析，将归化菌株与宿主相关的菌株区分开来，表明这些菌株可能共同代表了一种新型生态型，最近出现在与食物和水相关的工程环境中。有趣的是，泛基因组分析显示，归化菌株表现出丰富的生物膜形成、防御和消毒相关的抗胁迫基因，但缺乏各种毒力和定植基因，表明它们的归化是以在原始宿主环境中的适应性为代价的。
