Emergence of a single clone of community-associated methicillin-resistant Staphylococcus aureus in southern Madrid children

INTRODUCTION. The observation of an increasing number of methicillin-resistant Staphylococcus aureus (MRSA) isolated from children prompted us to study the microbiological, epidemiological and clinical characteristics of these isolates. The possibility of some of them being community-acquired focused particularly our attention. METHODS. A retrospective analysis of all children with MRSA isolated at the Doce de Octubre hospital between January 2002 and June 2005 was conducted. Infections were clasified as community-acquired, hospital-acquired, or health-care associated. Isolates of MRSA were studied by pulsed-field gel electrophoresis (PFGE) and SSCmec typing. The presence of the gene encoding the Panton-Valentine leukocidin was also detected by PCR. RESULTS. MRSA were isolated from 17 patients. Seven isolates (42.2%) were community-acquired, corresponding to four cases of skin or soft-tissue infections, two otitis cases and one bacteremic pyomiositis. Six of seven community-acquired isolates had the same ECP pattern (genotype D), presented a type IV SSCmec, and were LPV toxin-producing and meticilin- resistant with no other associated resistances. CONCLUSION. To our knowledge, this study shows the presence of these community-acquired MRSA strains for the first time in Spain. The evidence of an apparently clonal spreading of community-acquired MRSA infections in children has important implications for public health and treatment strategies.