Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal; Department of Food Science, Cornell University, Ithaca, New York 14853, USA.
Department of Food Science, Cornell University, Ithaca, New York 14853, USA.
J Food Prot. 2014 Jan;77(1):150-70. doi: 10.4315/0362-028X.JFP-13-150.
Over the last 10 to 15 years, increasing evidence suggests that persistence of Listeria monocytogenes in food processing plants for years or even decades is an important factor in the transmission of this foodborne pathogen and the root cause of a number of human listeriosis outbreaks. L. monocytogenes persistence in other food-associated environments (e.g., farms and retail establishments) may also contribute to food contamination and transmission of the pathogen to humans. Although L. monocytogenes persistence is typically identified through isolation of a specific molecular subtype from samples collected in a given environment over time, formal (statistical) criteria for identification of persistence are undefined. Environmental factors (e.g., facilities and equipment that are difficult to clean) have been identified as key contributors to persistence; however, the mechanisms are less well understood. Although some researchers have reported that persistent strains possess specific characteristics that may facilitate persistence (e.g., biofilm formation and better adaptation to stress conditions), other researchers have not found significant differences between persistent and nonpersistent strains in the phenotypic characteristics that might facilitate persistence. This review includes a discussion of our current knowledge concerning some key issues associated with the persistence of L. monocytogenes, with special focus on (i) persistence in food processing plants and other food-associated environments, (ii) persistence in the general environment, (iii) phenotypic and genetic characteristics of persistent strains, (iv) niches, and (v) public health and economic implications of persistence. Although the available data clearly indicate that L. monocytogenes persistence at various stages of the food chain contributes to contamination of finished products, continued efforts to quantitatively integrate data on L. monocytogenes persistence (e.g., meta-analysis or quantitative microbial risk assessment) will be needed to advance our understanding of persistence of this pathogen and its economic and public health impacts.
在过去的 10 到 15 年中，越来越多的证据表明，李斯特菌在食品加工厂中多年甚至数十年的持续存在是这种食源性病原体传播的一个重要因素，也是许多人类李斯特菌病爆发的根本原因。李斯特菌在其他与食品相关的环境（如农场和零售场所）中的持续存在也可能导致食品污染，并将病原体传播给人类。虽然李斯特菌的持续存在通常是通过在给定环境中随时间采集的样本中分离出特定的分子亚型来确定的，但持久性的正式（统计）标准尚未定义。环境因素（例如，难以清洁的设施和设备）已被确定为持续存在的关键因素；然而，其机制还不太清楚。尽管一些研究人员报告说，持续存在的菌株具有特定的特征，可能有助于其持续存在（例如，生物膜形成和更好地适应应激条件），但其他研究人员并未发现持续存在的菌株与非持续存在的菌株在可能有助于持续存在的表型特征方面存在显著差异。本综述包括对与李斯特菌持续存在相关的一些关键问题的讨论，特别关注（i）在食品加工厂和其他与食品相关的环境中的持续存在，（ii）在一般环境中的持续存在，（iii）持续存在菌株的表型和遗传特征，（iv）生态位，以及（v）持续存在对公共卫生和经济的影响。尽管现有数据清楚地表明，李斯特菌在食物链的各个阶段的持续存在导致了成品的污染，但仍需要继续努力，定量整合李斯特菌持续存在的数据（例如，荟萃分析或定量微生物风险评估），以提高我们对该病原体持续存在及其经济和公共卫生影响的理解。
