Drug-Resistance Mechanisms in Vibrio cholerae O1 Outbreak Strain, Haiti, 2010
Figure 2. Phylogenetic tree illustrating the genetic relatedness between the Haiti integrating conjugative element (ICE) ICEVchHai1 and other ICEs described in Vibrio cholerae (ICEVchBan1, ICEVchBan9, ICEVchInd1, ICEVchInd4, ICEVchInd5, ICEVchMex1, and SXT). Each ICE is listed by an abbreviated name followed by geographic origin and isolation year of the isolate in this analysis. The sequence of ICEVchHai1 was aligned with the other V. cholerae ICE sequences by using the software Progressive Mauve (http://asap.ahabs.wisc.edu/mauve/download.php), and a neighbor-joining phylogenetic tree was constructed by using PHYLIP (PHYLIP [Phylogeny Inference Package] version 3.69; distributed by J. Felsenstein, Department of Genome Sciences, University of Washington, Seattle, WA, USA). Branch lengths indicate the genetic distance between the different ICEs. The ICEVchHai1 showed highest homology (5 single-nucleotide difference) to ICEVchInd5, an ICE first detected in an isolate of V. cholerae O1 in Sevagram, India, in 1994. The ICE sequences in the analysis can be accessed by using the following GenBank accession nos.: Ban1, GQ463139; Ind1, GQ463144; Ind4, GQ463141; Ind5, GQ463142; Mex1, GQ463143; Ban9, CP001485; and SXT, AY055428. The complete sequence of the ICEVchHai1 has been deposited into GenBank under accession no. JN648379. Scale bar indicates nucleotide substitutions per site.