| Summary: | This work aimed to determine the frequency and diversity of <i>Staphylococcus</i> species carriage in horses intended for human consumption, as well as their resistance and virulence determinants. Eighty samples (30 nasal; 50 faecal) were recovered from 73 healthy horses in a Spanish slaughterhouse. The samples were cultured for staphylococci and methicillin-resistant staphylococci (MRS) recovery. The phenotype/genotype of antimicrobial resistance was analysed for all isolates. The <i>spa</i>-type and sequence-type (ST) were determined in <i>Staphylococcus aureus</i> strains; moreover, the presence of virulence and host-adaptation genes (<i>tst</i>, <i>eta, etb, pvl</i>, <i>lukPQ</i>, <i>scn-eq,</i> and <i>scn</i>) was studied by PCR. <i>Staphylococcus</i> species were detected in 27/30 (90%) and 33/50 (66%) of nasal and faecal samples, respectively. Ninety isolates belonging to eight species were recovered, with predominance of <i>S. aureus</i> (<i>n</i> = 34), <i>Staphylococcus delphini</i> (<i>n</i> = 19), and <i>Staphylococcus sciuri</i> (<i>n</i> = 19). <i>S. aureus</i> strains were all methicillin-susceptible (MSSA), 28/34 were susceptible to all the antibiotics tested, and the remaining six showed resistance to (gene-detected) streptomycin (<i>ant</i> (6)-<i>Ia</i>), penicillin (<i>blaZ</i>), and trimetroprim/sulphametoxazole (SXT) (<i>dfrA</i>, <i>dfrG</i>). The lineage ST1640/t2559 was predominant (<i>n</i> = 21). The genes <i>lukPQ</i> and <i>scn-eq</i> were present in all but the ST1640 isolates. Three <i>S. sciuri</i> isolates were multidrug-resistant. Healthy horses in Spain seem to be a reservoir for virulent MSSA and the lineage ST1640, although the presence of the latter in horses is described for the first time in this study. Moreover, the equine-adapted leukocidin gene <i>lukPQ</i> is frequent among <i>S. aureus</i> strains. A large variety of staphylococcal species with low antibiotic resistance rate were also observed.
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