In addition, all positive samples were tested for the occurrence of staphylococcal enterotoxins A, B, C and D
by reverse passive latex agglutination (SET-RPLA-Toxin Detection kit, Thermo Fisher Scientific, Wesel, Germany) according to the manufacturer's instructions with one exception (use of brain heart infusion broth (Becton-Dickinson Heidelberg, Germany) instead of tryptone soya broth).