Identifying Gene Expression Profiles Associated with Enhanced Stress Tolerance in Outbreak and Non-Outbreak Associated Salmonella Enterica

Whether through forming sanitation-resistant biofilms or developing enhanced tolerance toantimicrobials and sanitizers or even heat, foodborne pathogens adapt to and survive the stresses offood processing and sanitation program leading to consumer illnesses. Consequently, understandingbacterial pathogens' stress tolerance strategies and persistence capabilities and developing newmethods to foil them is crucial to reducing the burden of foodborne illness. Previous researchindicated that several isolates from an outbreak of Salmonella Heidelberg in poultry products hadincreased stress tolerance and that this was associated with enhanced stress tolerance geneexpression in stationary phase. I hypothesize that enhanced stress tolerance may play a key role inoutbreaks of salmonellosis and that this may be detectable via gene expression analysis instationary phase. The goal of this project is to determine the connection between stress tolerance inSalmonellaisolatesand outbreaks by completing the following objectives:Objective I: Determine heat tolerance, attachment capacity, and sanitizer tolerance of outbreakassociatedand non-outbreak associated food isolates from Salmonella enterica serovarsTyphimurium, Enteritidis, Heidelberg, and I 4,[5]12:i-Objective II: Characterize genetic features of isolates from Objective I via bioinformatics analysisof whole genome sequences from NCBI.Objective III: Compare stationary phase transcriptomes of stress tolerant and stress-sensitiveisolates from Salmonella enterica serovars Typhimurium, Enteritidis, Heidelberg, and I 4,[5]12:i-