Systemic infection caused by the methicillin-resistant Staphylococcus aureus USA300-LV lineage in a Brazilian child previously colonized

The methicillin-resistant Staphylococcus aureus (MRSA) USA300-Latin American variant (USA300-LV) lineage is well documented in northern Latin American countries. It has replaced established clones in hospital environments. We herein report a systemic infection caused by a USA300-LV isolate in a 15-year-old boy, from a low-income area of Rio de Janeiro, previously colonized by the same strain. During hospital stay, seven pvl-positive MRSA USA300-LV isolates were recovered by nasal swab, blood and abscess secretion. The patient underwent intravenous vancomycin, daptomycin, and oral sulfamethoxazole/trimethoprim, and was discharged after 45 days after full recovery. This is the first documented case of a community acquired MRSA infection caused by the USA300-LV variant in Brazil in a previously colonized adolescent with no history of recent travel outside of Rio de Janeiro. The need for improved surveillance programs to detect MRSA colonization in order to control the spread of hypervirulent lineages among community and hospital settings is highlighted. (author)