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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #375798

Research Project: Development of Portable Detection and Quantification Technologies for Foodborne Pathogens

Location: Characterization and Interventions for Foodborne Pathogens

Title: DsrA stimulates the oxidative stress resistance in Salmonella enterica serovar Typhimurium

item DONG, RUI - Shanghai Jiaotong University
item QIN, XIAOJIE - Shanghai Jiaotong University
item HE, SHOUKUI - Shanghai Jiaotong University
item ZHOU, XINJUAN - Shanghai Jiaotong University
item CUI, YAN - Shanghai Jiaotong University
item SHI, CHUNLEI - Shanghai Jiaotong University
item He, Yiping
item SHI, XIANMING - Shanghai Jiaotong University

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2020
Publication Date: 8/20/2020
Citation: Dong, R., Qin, X., He, S., Zhou, X., Cui, Y., Shi, C., He, Y., Shi, X. 2020. DsrA stimulates the oxidative stress resistance in Salmonella enterica serovar Typhimurium. Food Control. Available online:science/journal/09567135.

Interpretive Summary: This manuscript is the first study of the function of non-coding small RNA DsrA in oxidative stress response of Salmonella bacteria. Genetic and molecular biological studies of the natural versus the modified (dsrA gene removed) version of the same Salmonella strain, we found that the small RNA DsrA caused the bacterium to be resistant to oxidative stress It is presumed that this resistance was due to a mechanism that regulates the activation of oxidative stress response genes and thus results in the maintenance of reduction/oxidation balance in the Salmonella. The findings of this research are of great importance for the establishment of control measures for Salmonella contamination in the food industry.

Technical Abstract: Non-coding small RNAs (sRNAs) have been recognized as major regulators of bacterial stress response. The sRNA DsrA is known to be involved in acid tolerance response of Salmonella, while its role in the response to other stress factors such as oxidants remains unclear. The aim of this study was to characterize the function of DsrA in oxidative stress resistance of S. Typhimurium. Therefore, comparison analysis of survival rates, enzyme activity and gene expression patterns among the wild-type (WT), dsrA-deletion mutant ('dsrA) and complemented strain ('dsrA-C) was carried out in this study. It was found that deletion of DsrA led to a 2.5-log population reduction after exposure of S. Typhimurium to 3 mM H2O2 for 1 h in addition to cell membrane damage and intracellular ATP depletion. Moreover, the expression level of catalase and superoxide dismutase encoding genes (katEGN, sodABC) in the 'dsrA mutant was significantly (p < 0.05) lower than that in WT or 'dsrA-C, and the activity of these two enzymes was also decreased in the 'dsrA mutant. Meanwhile, the NAD+33 /NADH ratio surged in 'dsrA compared to the wild-type, which indicated the redox homeostasis was altered in the absence of DsrA. These results suggested that DsrA stimulates oxidative stress resistance in S. Typhimurium possibly by regulating the expression of antioxidant enzymes as well as maintaining the intracellular redox balance.