Staphylococcus aureus (MRSA and CA-MRSA strains) in South America: comparative review to emergence of strains in North America and worldwide

Background: In the last few years, 3 different strains of MRSA have emerged: Community-associated Methicillin-resistant S. aureus (CA-MRSA), Hospital-associated (HA-MRSA), and Livestock-associated (LA-MRSA). The most common CA-MRSA strain is USA 300 lineage. In Brasil, this superbacteria is an important public health problem, once they are associated with severe infections (sepsis, shock and osteomyelitis), high mortality rates (including babies) and low response to usual treatments. Aim: To review attempts to compare CA-MRSA strains in South America and propose an interconnection with patterns of North America and worldwide strains. Methods: Non-systematic review. Findings: Epidemiological and Genotyping definitions were used to compare different strains in different continents. Thus, we could determine ST30+ as the most common lineage in the Brazil and South America, USA 300 lineage as the most common in North America and ST80+ as the most common in Europe. Conclusion: MRSA is a seriously public health problem in Brazil and worldwide. In few years scientist will need a better understand of bacteria-derived factors that participate in enhanced MRSA pathogenesis & host susceptibility. Also, scientists will need to improve tools for an early diagnosis and they will need to enhance preventative/therapeutic modalities. However, new challenges will keep emerging.