Genetic, physiological, and cellular heterogeneities of bacterial pathogens in food matrices: Consequences for food safety

Abstract

In complex food systems, bacteria live in heterogeneous microstructures, and the population displays phenotypic heterogeneities at the single‐cell level. This review provides an overview of spatiotemporal drivers of phenotypic heterogeneity of bacterial pathogens in food matrices at three levels. The first level is the genotypic heterogeneity due to the possibility for various strains of a given species to contaminate food, each of them having specific genetic features. Then, physiological heterogeneities are induced within the same strain, due to specific microenvironments and heterogeneous adaptative responses to the food microstructure. The third level of phenotypic heterogeneity is related to cellular heterogeneity of the same strain in a specific microenvironment. Finally, we consider how these phenotypic heterogeneities at the single‐cell level could be implemented in mathematical models to predict bacterial behavior and help ensure microbiological food safety.

Design and validation of a dual-fluorescence reporter system to monitor bacterial gene expression in the gut environment

“…Over the last 20 years, many works demonstrate that clonal microbial cells cultured in homogeneous conditions can display significant diversity in their gene expression level, a phenomenon called phenotypic heterogeneity (Avery 2006;Bury-Moné and Sclavi 2017). This variability originates from stochasticity in gene expression but multiples drivers occurring at pre-transcriptional, transcriptional and post-transcriptional levels have been described in the literature (Martin et al 2022). Particularly, it has been proposed that cellular metabolic pathways in bacteria inherently follow stochastic processes and is a generic source of phenotypic heterogeneity (Kiviet et al 2014;Takhaveev and Heinemann 2018).…”

Assessing the relevance of different sources of variability on the survival of foodborne pathogens: stress adaptation against genetic heterogeneities

“…These differences can result in phenotypic diversity among cells in terms of their behaviour, morphology, or response to stimuli. For example, differences in gene expression patterns can lead to differences in the production of certain enzymes or virulence factors, which can affect the ability of the organism to cause disease (Martin et al, 2022).…”