Epidemiology of Staphylococcus aureus in pigs and farmers in the largest farm in Dakar, Senegal.

Between December 2009 and November 2011, we collected 57 (12.3%) Staphylococcus aureus isolates from 464 pigs and 16 (30.8%) isolates from 52 farmers in the largest farm in Dakar. Fifty-one isolates (70%) belonged to four major multilocus sequence typing clonal complexes (CCs): CC152 (26.0%), CC15 (19.2%), CC5 (13.7%), and CC97 (10.9%). The CC variability among the pigs was similar to that observed among the farmers. Six isolates that were recovered only among pigs were resistant to methicillin (10.5%). They were assigned to the ST5-staphylococcal cassette chromosome mec type (SCCmec) IV (n = 5) and ST88-SCCmec IV (n = 1) clones. The luk-PV genes encoding Panton-Valentine leukocidin (PVL), present in 43 (58.9%) isolates overall, including all major CCs and the MRSA ST5-SCCmec IV clone, were highly prevalent compared to data from industrialized countries. This finding is of major concern with regard to the potential virulence of these strains.