Mycobacterium doricum Osteomyelitis and Soft Tissue Infection

in Nicaragua in 2006 and 2008. The bootstrap support for this grouping was 100%. Phylogenetic analyses with neighbor-joining, maximumparsimony, and Bayesian methods gave trees with similar topologies, including clear separation of most recent Central American isolates into 1 clade, as well as grouping of the Key West sequence with the same 2 isolates from Nicaragua (data not shown). No protein coding changes between these strains were identifi ed, which suggests purifying selection for an optimum phenotype. There were 8 synonymous differences over the 1,708-nt amplifi ed region between the Key West and Nicaragua 2008 sequences. Previous molecular clock determinations for DENV-1 provided a range of 2.5–7.0 × 10–4 substitutions per nucleotide per year (8). This calculation produced an estimate of a 6.7–18.7-year divergence time between the Key West virus and the most closely related Nicaragua strain. When during this time the ancestor of Key West DENV was introduced to Florida is unknown. Analysis of the entire Key West DENV-1 genome may help pinpoint the origin and address the possibility of selective pressure on other genes or recombination events (9). Given the recent reports of DENV in residents of other Florida counties who had no travel histories (2), monitoring of Key West and other nearby urban areas for evidence of local DENV transmission should continue.