Comparative genetic analysis of acid resistance in Salmonella Typhimurium 14028s and Salmonella Typhi Ty2

ABSTRACT: Salmonella strains encounter significant acid stress during gastrointestinal infection and within the intra-phagosome environment. Comparative studies on acid adaptation of typhoidal and non-typhoidal Salmonella (NTS) are limited. In this study, we compared the growth of S. Typhimurium 14028s and S. Typhi (Ty2) across pH range of 3-8 and observed that Salmonella enterica serovar Typhimurium exhibit enhanced growth at pH 4.5 compared to S. Typhi. Comparative transcriptomic profiling of S. Typhimurium and S. Typhi at acidic and neutral pH identified numerous differentially expressed genes (DEGs) in both the serovars. These DEGs include genes encoding membrane proteins, transcriptional regulators, and stress response proteins. Targeted deletion of these genes in S. Typhimurium significantly suppressed growth at acidic pH, confirming their role in acid response. Notably, we found that these resistance mechanisms are compromised in S. Typhi due to pseudogenization of several key genes. Heterologous expression of these pseudogenized genes in S. Typhi augmented its acid tolerance. Collectively, our findings suggest that multiple genes essential for acid survival in S. Typhimurium have become dispensable or lost in S. Typhi reflecting divergent evolutionary strategies between these two serovars.

ORGANISM(S): Salmonella enterica subsp. enterica serovar Typhi Salmonella enterica subsp. enterica serovar Typhimurium

PROVIDER: GSE317267 | GEO | 2026/09/10

REPOSITORIES: GEO