Pediatric cases from Colombia caused by a Panton-Valentine Leukocidin-positive community-acquired methicillin-resistant Staphylococcus aureus ST8-SCCmecIVc clone.

To the Editor: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection is on the increase throughout the world. Panton-Valentine Leukocidin-positive (PVL) S. aureus strain dissemination in the community represents a public health concern about severe complications in children. Infections for CA-MRSA ST8, clonally related with USA300, have recently appeared in Colombia. We are reporting the first pediatric CAMRSA infection cases that occurred in Bogotá between June 2004 and May 2006. The first case concerned a previously healthy 14-year-old boy who developed severe sepsis with multiorgan failure, infectious endocarditis of the tricuspid valve, and septic pulmonary embolism associated with deep vein thrombosis, bilateral pyomyositis, and osteomyelitis of the lower extremities; he recovered after prolonged medical and surgical treatment. The second case involved a 9-month-old male with congenital Toxoplasma infection who developed respiratory failure associated with pneumonia and cervical cellulitis and responded to antimicrobial therapy. The third case concerned a 16-yearold boy from Bogotá with a history of recurrent furuncles associated with spontaneous drainage in his lower extremities during the previous 3 months. He was admitted because of an acute onset of progressive inflammatory local signs in the left inguinal area that limited his walking; he responded to medical and surgical treatment. The 3 isolates recovered from patients were confirmed as MRSA, the presence of nuc and mecA genes having been detected by polymerase chain reaction. The minimal inhibitory concentrations (MICs) were determined by using the agar diffusion test, according to Clinical and Laboratory Standards Institute. The oxacillin MICs for the 3 isolates were 32, 4, and 8 g/mL, respectively. The third MRSA exhibited the MLSB constitutive phenotype in double-disk diffusion assay (D test), with erythromycin ( 64 g/mL MIC) and clindamycin resistance (32 g/mL MIC). The 3 isolates were positive for the PVL genes (lukF-PV and lukS-PV) and harbored SCCmec type IVc. The 3 MRSA isolates SmaI macrorestriction profiles revealed 3 unique patterns clustering above 87% similarity into 1 pulsed-field gel electrophoresis type by computer analysis. The 3 strains were ascribed to ST8 by multilocus sequence typing belonging to the same sequence type as USA300, a common pulsedfield gel electrophoresis type in the United States with a similarity higher than 75%. These 3 isolates were not epidemiologically related. The clinical spectrum of the cases ranged from mild to severe infection. All cases showed some degree of skin, deep soft tissue, or bone compromise, as has been frequently described in children, and similar to the first report of adult cases from Columbia. Molecular typing identified these 3 isolates as belonging to the ST8-MRSA-IVc clone; they carried the PVL genes often associated with CA isolates. A retrospective report has suggested that CA-MRSA strains have been circulating in Colombia since 2001; they may have been ignored, along with their significant public health implications. Awareness about what is happening in our country will help us to evaluate the current state of our epidemiology regarding CA-MRSA infection and to develop strategies of infection control, following the lead of several other countries.