Uncommon Salmonella Infantis variants displaying only flagellar antigens phenotypically showed identical incomplete antigenic formula but differed by molecular serotyping. Although most formed rough colonies, all shared antimicrobial resistances and the presence of usg gene with wild-type Salmonella Infantis. Moreover, they were undistinguishable wild-type Salmonella Infantis by whole-genome sequencing.
Keywords: Italy; Salmonella Infantis; Salmonella enterica; Salmonellae; bacteria; emerging atypical variants; enteric infections; food safety; poultry.