In Silico Characterization of Toxin-Antitoxin Systems in Isolates Recovered from Food Sources and Sporadic Human Illness.

spp. represents the most common cause of gastroenteritis worldwide with the potential to cause serious sequelae. The ability of to survive stressful environmental conditions has been directly linked with food-borne illness. Toxin-antitoxin (TA) modules play an important role as defense systems against antimicrobial agents and are considered an invaluable strategy harnessed by bacterial pathogens to survive in stressful environments. Although TA modules have been extensively studied in model organisms such as , the TA landscape in remains largely unexplored. Therefore, in this study, a comprehensive in silico screen of 111 (90 and 21 ) isolates recovered from different food and clinical sources was performed. We identified 10 type II TA systems belonging to four TA families predicted in genomes. Furthermore, there was a significant association between the clonal population structure and distribution of TA modules; more specifically, most (12/13) of the isolates belonging to ST-21 isolates possess TA modules. Finally, we observed a high degree of shared synteny among isolates bearing certain TA systems or even coexisting pairs of TA systems. Collectively, these findings provide useful insights about the distribution of TA modules in a heterogeneous pool of isolates from different sources, thus developing a better understanding regarding the mechanisms by which these pathogens survive stressful environmental conditions, which will further aid in the future designing of more targeted antimicrobials.