Population structure of clinical and environmental strains.

<p>A phylogenetic tree of strains was constructed from data from a filtered set of 150,306 SNP sites, using RRHS and Maximum Likelihood (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1007138#sec024" target="_blank">Methods</a>). Branch supports represent pseudo-bootstrap values. Strains named in red are clinical isolates, and strains named in blue are environmental. For each strain, four circles indicate relative resistance (magenta) or relative sensitivity (green) to four drugs as shown in the key.