As a facultative intracellular pathogen, Salmonella Enteritidis must develop an effective oxidative stress response to survive exposure to reactive oxygen species within the host. To study this defense mechanism, we carried out a series of oxidative stress assays in parallel with a comparative transcriptome analyses using a next generation sequencing approach. It was shown that the expression of 45% of the genome was significantly altered upon exposure to H2 O2 . Quantitatively the most significant (≥100 fold) gene expression alterations were observed among genes encoding the sulfur utilization factor of Fe-S cluster formation and iron homeostasis. Our data point out the multifaceted nature of the oxidative stress response. It includes not only numerous mechanisms of DNA and protein repair and redox homeostasis, but also the key genes associated with osmotic stress, multidrug efflux, stringent stress, decrease influx of small molecules, manganese and phosphate starvation stress responses. Importantly, this study revealed that oxidatively stressed S. Enteritidis cells simultaneously repressed key motility encoding genes and induced a wide range of adhesin-and salmonellae-essential virulence-encoding genes, that are critical for the biofilm formation and intracellular survival, respectively. This finding indicates a potential intrinsic link between oxidative stress and pathogenicity in non-typhoidal Salmonella that needs to be empirically evaluated.
Bibliographical noteFunding Information:
Funding: This research was funded by the United States Department of Agriculture, National Institute of Food and Agriculture, Hatch Capacity Grant # 592 and Grant-in-Aid of Research, Artistry and Scholarship, University of Minnesota, USA.
Acknowledgments: The authors gratefully acknowledge the technical support from Daniela Vidovic. The present study was also supported, in part, by resources provided by the Minnesota Supercomputing Institute.
- Biofilm formation
- Next generation sequencing
- Non-typhoidal Salmonella
- Oxidative stress response
- Salmonellae-essential virulence genes
PubMed: MeSH publication types
- Journal Article