F74 plasmids are major vectors of virulence genes in bovine NTEC2

Abstract

Significance and Impact of the Study: Successful plasmids, that is geographically widespread and present in different hosts or matrices, carrying resistance determinants have been widely characterized, several of them belonging to the IncF family. Plasmids encoding specific virulence factors (VFs) are much less reported. In this study, we characterized 32 NTEC2 isolates collected from French sick and healthy calves and identified the occurrence of highly similar F74 plasmids carrying the cnf2 gene, most likely associated with cdtIII, ompP and F17 variants when present in the isolates. These F74 plasmids are thus successful vectors of VFs in bovine in France, but also in the United Kingdom and United States as found in the publically available databases. This is of One Health significance since NTEC2 is found in bovine but also in derived foodstuff and in humans.