Work

Comparative transcriptomics of outbreak-associated Salmonella Heidelberg, Typhimurium, and monophasic Typhimurium reveals differential expression of stress tolerance, virulence, and biofilm-associated genes

Year: 2026

Type: article

Abstract: Non-typhoidal Salmonella enterica remains a leading cause of foodborne illness worldwide, with certain serovars more commonly implicated in outbreaks linked to specific food matrices. However, gene expression differences between distinct serovars remain poorly understood, which may limit the ability to reduce the overall outbreak and illness burden. This study presents an RNA-Seq evaluation of six outbreak-associated, stationary-phase S. enterica transcriptomes representing serovars Salmonella Heidelberg, Salmonella Typhimurium, and monophasic Salmonella Typhimurium (I 4,[5],12:i-). Analysis of differential gene expression ( p adj < 0.05 and |log2FoldChange| > 1) revealed upregulation of genes associated with enhanced pathogenicity among all strains; however, Salmonella Heidelberg exhibited a transcriptional profile consistent with enhanced invasion, iron metabolism, and biofilm formation, while Salmonella Typhimurium and monophasic Salmonella Typhimurium showed transcriptional profiles consistent with stress response and survival. Transcriptome patterns were concordant with previous research evaluating phenotypic stress responses, in which Salmonella Heidelberg demonstrated prolonged survival at lethal temperatures and enhanced biofilm-forming capabilities. Overall, these findings suggest that outbreak-associated strains may employ distinct transcriptional strategies that could contribute to serovar-specific outbreak characteristics. This work supports risk assessment modeling to ultimately improve food safety interventions and reduce the public health burden of S. enterica .

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1895105

Authors: Chelsey A. Patch, Andrea J. Etter

Institution: University of Vermont

Language: English

Topic: Salmonella and Campylobacter epidemiology

Subfield: Food Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,801