Abstract: Salmonella and Listeria monocytogenes are considered as the major foodborne pathogens in meat products. Both pathogens can develop a strong tolerance response to a weakly acidic environment inducing high toxicity and resistance to acid and osmotic pressure, which poses potential health hazards to consumers. In this article, we mainly review the history of the discovery of the acid tolerance response (ATR) of Salmonella and Listeria monocytogenes, the hazards of ATR and the factors affecting its development. Furthermore, we elucidate the molecular mechanism of ATR based on intracellular pH modulation, stress proteins and cell membrane composition and fluidity.

Key words: food safety, Salmonella, Listeria monocytogenes, acid tolerance response, molecular mechanism