Global transcriptomic Acid Tolerance Response in Salmonella Enteritidis

Abstract

Salmonella is a major foodborne pathogen throughout the world and able to resist extreme acid stress such as stomach gastric juice after mild acid adaptation, which makes it a potential hazard in food industry. We conducted a comparative transcriptomic analysis by high-throughout RNA-seq to elucidate the Acid Tolerance Response (ATR) in Salmonella Enteritidis. Among these 554 differentially expressed genes (DEGs) identified in this study, the expression of 280 DEGs were up-regulated and 274 DEGs were down-regulated. First, S. Enteritidis tried to survive the adverse environment by reducing the energy-consuming metabolisms and maintaining essential processes as an energy conservation strategy. Second, ATR S. Enteritidis underwent damages in DNA, an oxidization damage result in an iron-lacking circumstance and so on. Thus DEGs related to Fe/S cluster biogenesis, stress response regulating proteins and transport proteins were responsive to acid stress to repair damage caused by acid and ROS. Last, to balance extra protons, by increasing the intracellular NAD (+)/NADH ratio, S. Enteritidis could also decline the protein acetylation level by promoting the consumption of acetyl coenzyme A via TCA, to prevent the intracellular pH from further decline under acid stress.