LAUSR

Multidrug-resistant (MDR) Salmonella enterica has been deemed a high-priority pathogen by the World Health Organization. Two hundred and sixty-four Salmonella enterica isolates recovered over a 16-year period (2000 to 2016) from the poultry and swine production chains, in Brazil, were investigated by whole-genome sequencing (WGS). Most international lineages belonging to 28 serovars, including, S. enterica serovars S. Schwarzengrund ST96, S. Typhimurium ST19, S. Minnesota ST548, S. Infantis ST32, S. Heidelberg ST15, S. Newport ST45, S. Brandenburg ST65 and S. Kentucky ST198 displayed MDR and virulent genetic backgrounds. In this regard, resistome analysis revealed presence of qnrE1 (identified for the first time in S. Typhimurium from food chain), qnrB19, qnrS1, bla CTX-M-8, bla CTX-M-2 and bla CMY-2 genes, as well as gyrA mutations; whereas ColpVC, IncHI2A, IncHI2, IncFIA, Incl1, IncA/C2, IncR, IncX1 and po111 plasmids were detected. In addition, phylogenetic analysis revealed multiple independent lineages such as S. enterica serovars S. Infantis, S. Schwarzengrund, S. Minnesota, S. Kentucky and S. Brandenburg. In brief, ocurrence and persistence of international lineages of S. enterica serovars in food production chain is supported by conserved genomes and wide virulome and resistome.