Transcriptomic Approach for Understanding the Adaptation of to Contaminated Produce.

Salmonellosis is a form of gastroenteritis caused by infection. The main transmission route of salmonellosis has been identified as poorly cooked meat and poultry products contaminated with . However, in recent years, the number of outbreaks attributed to contaminated raw produce has increased dramatically. To understand how adapts to produce, transcriptomic analysis was conducted on enterica serovar Virchow exposed to fresh-cut radish greens. Considering the different lifestyles in contact with fresh produce, such as motile and sessile lifestyles, total RNA was extracted from planktonic and epiphytic cells separately. Transcriptomic analysis of S. Virchow cells revealed different transcription profiles between lifestyles. During bacterial adaptation to fresh-cut radish greens, planktonic cells were likely to shift toward anaerobic metabolism, exploiting nitrate as an electron acceptor of anaerobic respiration, and utilizing cobalamin as a cofactor for coupled metabolic pathways. Meanwhile, cells adhering to plant surfaces showed coordinated upregulation in genes associated with translation and ribosomal biogenesis, indicating dramatic cellular reprogramming in response to environmental changes. In accordance with the extensive translational response, epiphytic cells showed an increase in the transcription of genes that are important for bacterial motility, nucleotide transporter/metabolism, cell envelope biogenesis, and defense mechanisms. Intriguingly, pathogenicity island (SPI)-1 and SPI-2 displayed up- and downregulation, respectively, regardless of lifestyles in contact with the radish greens, suggesting altered virulence during adaptation to plant environments. This study provides molecular insights into adaptation to plants as an alternative environmental reservoir.