Molecular tracing of the emergence, diversification, and transmission of S. aureus sequence type 8 in a New York community

摘要: During the last 2 decades, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains have dramatically increased global burden of S. infections. The pandemic sequence type (ST)8/pulsed-field gel USA300 is dominant CA-MRSA clone in United States, but its evolutionary history and basis for biological success are incompletely understood. Here, we use whole-genome sequencing 387 ST8 isolates drawn from an epidemiological network infections colonizations northern Manhattan to explore short-term evolution transmission patterns. Phylogenetic analysis predicted that diverged a most common recent ancestor around 1993. We found evidence multiple introductions reconstructed phylogeographic spread across neighborhoods. Using pair-wise single-nucleotide polymorphism distances as measure genetic relatedness between isolates, observed had become endemic households, indicating their critical role reservoirs diversification. maximum variability within households threshold, identified several possible networks beyond households. Our study also revealed fluoroquinolone-resistant subpopulation mid-1990s subsequent expansion at time high-frequency outpatient antibiotic use. This high-resolution phylogenetic has documented genomic changes associated with how some been shaped by By integrating detailed analyses, our provides important framework delineating full diversity other emerging pathogens large urban community populations.