Impact of Pathogen Population Heterogeneity and Stress-Resistant Variants on Food Safety

Abstract

This review elucidates the state-of-the-art knowledge about pathogen population heterogeneity and describes the genotypic and phenotypic analyses of persister subpopulations and stress-resistant variants. The molecular mechanisms underlying the generation of persister phenotypes and genetic variants are identified. Zooming in on Listeria monocytogenes, a comparative whole-genome sequence analysis of wild types and variants that enabled the identification of mutations in variants obtained after a single exposure to lethal food-relevant stresses is described. Genotypic and phenotypic features are compared to those for persistent strains isolated from food processing environments. Inactivation kinetics, models used for fitting, and the concept of kinetic modeling-based schemes for detection of variants are presented. Furthermore, robustness and fitness parameters of L. monocytogenes wild type and variants are used to model their performance in food chains. Finally, the impact of stress-resistant variants and persistence in food processing environments on food safety is discussed.

Emergence of Antibiotic Resistance in Listeria monocytogenes Isolated from Food Products: A Comprehensive Review

“…Persister cells are dormant, non‐dividing state with enhanced capability to survive environmental stresses (Buchanan et al., ; Knudsen, Holch, & Gram, ). It could also contribute to L. monocytogenes protection against cleaning and sanitation in food processing environment (Abee, Koomen, Metselaar, Zwietering, & den Besten, ).…”

Persistent Listeria monocytogenes strains isolated from mussel production facilities form more biofilm but are not linked to specific genetic markers

“…The ability of strains to persist in a food-processing environment has been the topic of two reviews (Carpentier andCerf 2011, Ferreira et al 2014), however the reason for persistence remains poorly understood. Persistence of strains in food-processing plants can either be due to genotypic and phenotypic features that facilitate the expression of specific genes and lead to enhanced tolerance towards environmental threats, or to the attachment of bacteria to niches and harbourage sites by chance and subsequent survival due to insufficient cleaning and sanitation procedures (Abee et al 2016).…”

Influence of Environmental Factors on Phage–Bacteria Interaction and on the Efficacy and Infectivity of Phage P100

“…Nevertheless, it is possible that some of our data are not directly applicable to all L. monocytogenes strains. However, in food production plants or natural environments there is always heterogeneity of bacteria and stress-resistant variants can be found ( Abee et al, 2016 ). For example, in general L. monocytogenes serotypes 4 and 1/2 were more susceptible to phages compared to strains in other serotypes, however is was reported that in food production plants within one serotype both, phage susceptible and phage insensitive isolates, can be found ( Vongkamjan et al, 2012 , 2013 ; Fister et al, 2016 ).…”