Emergence of CMY-2-Producing Salmonella Heidelberg Associated with IncI1 Plasmids Isolated from Poultry in Brazil

In this study we report the characterization of plasmid-mediated CMY-2-producing Salmonella Heidelberg recovered from food, poultry, and poultry environment in Brazil, between 2014 and 2016. The bla CMY-2 resistance gene was allocated in large (90–148 kb) IncI1 type transferable plasmids. Salmonella Heidelberg isolates were genetically related, indicating the dissemination of closely related isolates among food, poultry, and its environment. This is the first report of IncI1 replicon-types of plasmids encoding the bla CMY-2 resistance gene in Salmonella Heidelberg isolates in Brazil, the world's biggest exporter of chickens.