Low temperature preservation for perishable ready to eat foods: Not entirely effective for control of L. monocytogenes

Background: As one of the few effective methods to extend the shelf life and ensure safety of some perishable ready to eat (RTE) foods, low temperature preservation has been challenged by pathogens that can tolerate and adapt to low temperature. L. monocytogenes ability of adaption to low temperature is one of the key attributes that support its persistence and spread under low temperature, which makes it insufficient to control L. monocytogenes on those ready to eat (RTE) foods by low-temperature setting.Scope and approach: In this paper, adaptive mechanism and phenotypic changes of L. monocytogenes under cold temperature are comprehensively demonstrated. In addition, cold stress sensing, signal transduction, genes regulation, adverse effect of cold adaption and feasible methods for prevention of cold adaption are emphatically demonstrated as well.Key findings and conclusions: When encountering cold stress, two-component signal transduction system in L. monocytogenes is the important regulatory networks that responsible for the cold signal transmit. In response to cold stress, L. monocytogenes has adapted a series of mechanisms including changes in fatty acid composition, intracellular uptake of compatible solutes and production of cold shock proteins, which are largely regulated by Sigma B transcription factor. In addition, the cold stimulation may induce the cross protection for other stresses, resulting in the potential elevation in virulence and toxin secretion of L. monocytogenes. Finally, the inhibition for the autophosphorylation of histidine residue in histidine kinase may provide a feasible method for the prevention of cold adaption of L. monocytogenes.