Abstract

Salmonella Minnesota has emerged in Brazil as the predominant serovar in poultry and poultry products, along with Salmonella Heidelberg. To understand the emergence of Salmonella Minnesota over the last few years in Brazil, we performed a comparative analysis between 69 selected S . Minnesota genomes from Pathogen Detection database and 65 clonal emergent genomes isolated from Brazil. We demon strate the presence of multidrug resistance genes against tetracycline [tet(A)], sulfona mide (sul2), and AmpC beta-lactamase (blaCMY-2) in emergent genomes, along with the carriage of a megaplasmid of resistance and virulence (similar to 210 kb), designated pESM (plasmid for emergent Salmonella Minnesota). pESM is an IncC/A2 plasmid predicted to increase S . Minnesota environmental tolerance to mercury ( mer operon) and provide resistance to tetracycline and ampicillin due to the presence of tet (A) and bla CMY-2 , respectively. Moreover, pESM carries the yersiniabactin siderophore (high-pathogenicity island of Yersinia) related to the iron uptake. The temporal inference demonstrated that the most recent common ancestor dated from similar to 1978 and that the clonal emergent genomes carrying the pESM belong to a completely different lineage of S . Minnesota. Our results indicate that the presence of pESM likely contributes to the emergence of S . Minnesota and is precisely related to the successful spread of this particular clonal lineage in Brazil.