Panton-Valentine leukocidin (PVL) gene carriage among Staphylococcus aureus strains with SCCmec types I, III, IV, and V recovered from cystic fibrosis pediatric patients in Brazil

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing in patients with cystic fibrosis (CF). We report a molecular characterization, antimicrobial resistance, and Panton-Valentine leukocidin (PVL) toxin gene detection of MRSA strains from 28 Brazilian pediatric CF patients (1 strain per patient). A significant proportion (50%) of MRSA SCCmec IV isolates was observed. Nearly half of MRSA strains harboring the PVL genes distributed in all SCCmec types detected. Multilocus sequence typing (MLST) analyses showed majority (57.1%) of the isolates belonged to known epidemic lineages, such as UK/EMRSA-3, Pediatric/USA 800, Southwest Pacific clone, and Brazilian/Hungarian clone. To our knowledge, this is the first Brazilian study of molecular epidemiology based on MLST and SCCmec typing and the first description of PVL genes in MRSA from CF patients.