Abstract

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a globally recognized foodborne pathogen that affects both animals and humans. Endoribonucleases mediate RNA processing and degradation in the adaptation of bacteria to environmental changes and have been linked to the pathogenicity of S. Typhimurium. Not much is known about the specific regulatory mechanisms of these enzymes in S. Typhimurium, particularly in the context of environmental adaptation. Thus, this study carried out a comparative transcriptomic analysis of wild-type S. Typhimurium SL1344 and its mutant (Δrnc), which lacks the rnc gene encoding RNase III, thereby elucidating the detailed regulatory characteristics that can be attributed to the rnc gene. Global gene expression analysis revealed that the Δrnc strain exhibited 410 upregulated and 301 downregulated genes (fold-change > 1.5 and p < 0.05), as compared to the wild-type strain. Subsequent bioinformatics analysis indicated that these differentially expressed genes are involved in various physiological functions, in both the wild-type and Δrnc strains. This study provides evidence for the critical role of RNase III as a general positive regulator of flagellar-associated genes and its involvement in the pathogenicity of S. Typhimurium.

• Keywords: RNS;ROS;Salmonella enterica serovar Typhimurium;intramacrophage growth;nitrosative stress;oxidative stress;small RNA RaoN;virulence