Whole-Genome Comparative and Pathogenicity Analysis of Salmonella enterica subsp. enterica Serovar Rissen

Salmonella are a type of bacteria known to cause food-borne illness. Their host range varies widely, and their susceptibility to the host determines its pathogenicity. Salmonella enterica serovar Rissen (S Rissen) is a widely distributed serotype; however, its virulence and pathogenicity are poorly understood. In this study, the pathogenicity and antibiotic resistance of a representative S Rissen isolate were investigated. The cell model results showed that S Rissen preferred to replicate in human macrophage cells U937 compared to murine macrophage cells RAW264.7, suggesting that it has a level of host adaptability. Genome sequencing and comparison analysis revealed that the distribution and nonsynonymous single nucleotide polymorphisms of virulence factors in S Rissen were similar to those in S Typhi rather than to those in S Typhimurium. Taken together, our results suggest that although S Rissen is a common serotype distributed in swine herds, pork and chicken products, it has strong ability to infect humans.