Environment and Public Health Research Group, Centre for Aquatic Environments, School of Environment and Technology, University of Brighton, Brighton, UK.
J Appl Microbiol. 2018 May;124(5):1274-1282. doi: 10.1111/jam.13700. Epub 2018 Feb 18.
The aim of this study was to determine the morphological diversity and environmental survival of human-specific phages infecting Enterococcus faecium host strain MW47, to support their use as microbial source tracking (MST) markers.
Twenty phages capable of infecting strain MW47 were propagated and their morphologies were determined using transmission electron microscopy (TEM), which revealed that a heterogeneous group of phages was able to infect strain MW47. Three distinct morphologies from two different families (Myoviridae and Siphoviridae) were observed. In situ inactivation experiments were subsequently conducted to determine their environmental persistence.
The findings revealed a statistically significant link between morphology and the rate of inactivation, with phages belonging to the Myoviridae family demonstrating more rapid inactivation in comparison to those belonging to the Siphoviridae family.
The results suggest that while Enterococcus MW47 phages appear to be a potentially valuable MST tools, significant variations in the persistence of the different phages mean that the approach should be used with caution, as this may adversely affect the reliability of the approach, especially when comparing MW47 phage levels or the presence across different matrices (e.g. levels in sediments or shellfish). This highlights the importance of elucidating the ecological characteristics of newly proposed MST markers before they are used in full-scale MST investigations.
本研究旨在确定感染屎肠球菌 MW47 宿主菌株的人特异性噬菌体的形态多样性和环境生存能力，以支持将其用作微生物源追踪（MST）标记物。
繁殖了 20 株能够感染 MW47 株的噬菌体，并使用透射电子显微镜（TEM）确定了它们的形态，结果表明能够感染 MW47 株的噬菌体是一组异质群体。观察到来自两个不同科（肌尾噬菌体科和长尾噬菌体科）的三种不同形态。随后进行了现场失活实验以确定它们的环境持久性。
研究结果表明，形态与失活率之间存在统计学显著关联，与属于长尾噬菌体科的噬菌体相比，属于肌尾噬菌体科的噬菌体的失活速度更快。
研究结果表明，虽然肠球菌 MW47 噬菌体似乎是一种有潜力的 MST 工具，但不同噬菌体的持久性存在显著差异，这意味着应谨慎使用该方法，因为这可能会对该方法的可靠性产生不利影响，特别是在比较 MW47 噬菌体水平或在不同基质（例如沉积物或贝类）中存在时。这突出表明，在将新提出的 MST 标记物用于全面 MST 调查之前，必须阐明它们的生态特征。
