Influence of Microbial and Host Cell Sublethal Heat Stress on S. Typhimurium Gene Expression

ABSTRACT: Environmental stress contributes to the outcome of infection by impacting both microbial virulence and host susceptibility to infection. Thermal processing, commonly used for decontamination of poultry in the food industry, may elicit sublethal stress on resistant serovars of Salmonella. We employed traditional heat shock temperatures (42 and 48ºC), similar to avian body temperature and poultry processing conditions, to study gene expression of Salmonella enterica serovar Typhimurium. Microarray analysis indicated that thermal shock at 42°C and 48°C induced expression of SPI-2 and SPI-5 genes, whose products are required for adhesion and survival. However, SPI-1 genes, responsible for invasion of Salmonella into host cells, were down-regulated following exposure to 42°C and 48°C. Bacterial adhesion assays showed greater adhesion of heat-stressed S. Typhimurium to Caco-2 cells compared to non-stressed bacteria. In addition, subjecting Caco-2 cells to mild heat shock (39°C), which is similar to human fever, enhanced host cell susceptibility to bacterial adhesion. Data indicate that thermal stress enhances bacterial colonization and host cell susceptibility to adhesion during S. Typhimurium infection.

ORGANISM(S): Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 Salmonella enterica subsp. enterica serovar Typhimurium

PROVIDER: GSE18089 | GEO | 2009/12/25

SECONDARY ACCESSION(S): PRJNA119373

REPOSITORIES: GEO