Figure 2. Neighbor-joining tree of 233 bp of unique internal transcribed spacer region sequences of 138 clinical isolates and reference strains of the Mycobacterium chelonae-abscessus complex. Branch support is recorded at nodes as a percentage of 1,000 bootstrap iterations. Clinical isolates are labeled by the identification, followed by the sequevar group and the number of isolates. Scale bar indicates nucleotide substitutions per site. ATCC, American Type Culture Collection; CV, M. chelonae variant; CIP, Collection of Institute Pasteur; CCUG, Culture Collection, University of Göteborg, Sweden.