Staphylococcus aureus positive for Panton-Valentine leukocidin genes but susceptible to methicillin in patients with furuncles

A total of 75 Staphylococcus aureus isolates obtained from patients with either recurrent skin abscesses or furuncles (n=48) or chronic infections from other body sites (n=27) were screened for the presence of the lukS-PV and lukF-PV genes encoding Panton-Valentine leukocidin. Significantly more isolates (70.8% vs. 7.4%, p < 0.001) from patients suffering skin abscesses or furuncles were positive for lukS-PV and lukF-PV. These isolates belonged to the accessory gene regulator (agr) group Ia (9/48), group III (13/48), or group IV (19/48). In contrast with results of other investigations, none of the isolates positive for the Panton-Valentine leukocidin genes in this study exhibited methicillin resistance.