Department of Food Science, University of Tennessee, Knoxville, TN, USA.
Department of Food Science, University of Tennessee, Knoxville, TN, USA.
Food Microbiol. 2019 Dec;84:103239. doi: 10.1016/j.fm.2019.06.003. Epub 2019 Jun 5.
Bacteriophage-based biocontrols are one of several tools available to control Listeria monocytogenes in food and food processing environments. The objective of this study was to determine if phage-resistance that has been characterized with a select few Listeria phages would also confer resistance to a diverse collection of over 100 other Listeria phages. We show that some mutations that are likely to emerge in bacteriophage-treated populations of serotype 1/2a L. monocytogenes can lead to cross-resistance against almost all types of characterized Listeria phages. Out of the 120 phages that showed activity against the parental strain, only one could form visible plaques on the mutant strain of L. monocytogenes lacking rhamnose in its wall teichoic acids. An additional two phages showed signs of lytic activity against this mutant strain; although no visible plaques were observed. The findings presented here are consistent with other studies showing mutations conferring phage resistance through loss of rhamnose likely pose the greatest challenge for phage-based biocontrol in serotype 1/2a strains.
基于噬菌体的生物防治是控制食品和食品加工环境中李斯特菌的几种工具之一。本研究的目的是确定是否已经用少数几种李斯特菌噬菌体表征的噬菌体抗性也能抵抗超过 100 种其他李斯特菌噬菌体的多样性。我们表明，在血清型 1/2a 李斯特菌噬菌体处理的种群中可能出现的一些突变可能导致对几乎所有类型的已鉴定李斯特菌噬菌体的交叉抗性。在对亲本菌株表现出活性的 120 种噬菌体中，只有一种能够在缺乏细胞壁磷壁酸中鼠李糖的李斯特菌突变菌株上形成可见噬菌斑。另外两种噬菌体对这种突变菌株表现出裂解活性的迹象；尽管没有观察到可见的噬菌斑。这里提出的发现与其他研究一致，表明通过失去鼠李糖赋予噬菌体抗性的突变可能对血清型 1/2a 菌株的基于噬菌体的生物防治构成最大挑战。
