Community-acquired methicillin-resistant Staphylococcus aureus in Madrid, Spain: transcontinental importation and polyclonal emergence of Panton–Valentine leukocidin-positive isolates

Abstract

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates producing the Panton–Valentine leukocidin (PVL) have been reported worldwide. We describe the molecular characteristics of PVL-positive CA-MRSA strains isolated in Madrid, Spain, and analyze the clinical features of patients infected with these isolates. From 2004 to 2007, we collected 13 PVL-positive MRSA isolates from patients attending to the emergency department. The isolates were genotyped by pulsed-field gel electrophoresis, SCC mec typing, agr polymorphism, and multilocus sequence typing. Susceptibility to 29 antimicrobials was determined by the broth microdilution and by the E-test methods. The isolates belonged to 3 genotypes: ST8-SCC mec IVc ( n = 11), ST5-SCC mec IVa ( n = 1), and ST80-SCC mec IVc ( n = 1). The corresponding agr types were I, II, and III, respectively. Five isolates were resistant to tetracycline and doxycycline, and 1 was resistant to fusidic acid (ST80). The isolates were from children ( n = 9) and adults ( n = 4), and were associated with skin and soft tissue infections ( n = 9), otitis ( n = 1), and bacteremia ( n = 1). Nine patients were from South America. Our results indicate the transcontinental importation and recent emergence in Spain of PVL-positive CA-MRSA strains belonging to 3 distinct lineages, including 1 predominant (ST8-SCC mec IVc).