Oxacillin resistance among Staphylococcus aureus isolated from peritoneal dialysis related peritonitis

Abstract

Peritonitis remains as the major cause of peritoneal dialysis failure, and Staphylococcus spp. are the main etiologic agents of these infections. Lower resolution rates are associated to Staphylococcus aureus episodes. Oxacillin resistance is an important factor in therapy definition, since it implies in resistance to all other eta-lactam antimicrobials. In this study, we aimed to evaluate the oxacillin resistance, mecA gene detection, and staphylococcal cassette chromosome surrounding mecA gene (SCCmec) in S. aureus samples isolated from peritonitis in patients on peritoneal dialysis, from a single center from 1996 to 2008. Oxacillin resistance was found in 10/69 (14.5%) strains, while mecA gene was detected in 8/69 (11.6%). SCCmec typing was carried out on mecA gene -positive strains, but only three strains could be identified: two as type ifi, and one as type IA. Determining SCCmec alerts to the possibility of acquiring these infections on hospital environment, once that these cassette are traditionally associated to nosocomial infections.