Type: Article

Whole genome sequencing reveals widespread distribution of typhoidal toxin genes and VirB/D4 plasmids in bovine-associated nontyphoidal Salmonella

Enrique Jesús Delgado-Suárez, Nelly Selem-Mojica, Rocío Ortiz-López, Wondwossen A Gebreyes, Marc W Allard, Francisco Barona-Gómez, María Salud Rubio-Lozano;

Abstract:

Nontyphoidal Salmonella (NTS) is a common pathogen in food-producing animals and a public health concern worldwide. Various NTS serovars may be present in apparently healthy animals. This could result in carcass contamination during the slaughter process leading to human exposure. While most genomic research has focused on Salmonella pathogenesis, little is known on the factors associated with subclinical infections and environmental persistence. We report here the widespread distribution of typhoidal toxin genes (i. e. the cdtB islet, hlyE, taiA), among NTS strains from a beef slaughter operation (n?=?39) and from epidemiologically unconnected ground beef (n?=?20). These genes were present in 76% of the strains, regardless of serovar, isolation source or geographical location. Moreover, strains that predominated in the slaughterhouse carry plasmid-borne type IV secretion systems (T4SS), which …