Conversely, it was not possible to detect 17 virulence factors, as identified in other isolates from mastitis, using the oligonucleotide primers available: a catabolic mobile gene (arcA), adhesin (srdE) and 15 cytotoxins (lukSF-PVL, lukMF-PV, sea, seb, sec, sed, see, seh, sej, selk, sel, selq, eta, etb, tst). This evidence concerns the gene SELENOK and mastitis.