Molecular typing of Mycobacterium abscessus based on tandem-repeat polymorphism

Abstract

A variable-number tandem-repeat (VNTR) typing assay for the differentiation of Mycobacterium abscessus strains was developed. This assay showed complete reproducibility, locus stability, and a discriminatory power (Hunter-Gaston discriminatory index [HGDI] of 0.9563) that is superior to that of multilocus sequencing. It is a promising tool for the investigation of Mycobacterium abscessus epidemiology and nosocomial outbreaks.

Fig 1

Dendrogram of 38 Mycobacterium abscessus strains based on MaVA results, created by using the Bionumerics v6.5 (Applied Math) UPGMA method. TR, tandem repeat. Strains M119 and M120, M159 and M161, and M127 and M149 were paired isolates from 3 patients. Strains M145 to M161 were identified with Mycobacterium massiliense, strain M24 with Mycobacterium bolletii, and strains M93 to M171 with Mycobacterium abscessus in the phylogenetic tree based on multilocus sequence data (Fig. 2).

Fig 2

Dendrogram of 34 Mycobacterium abscessus strains based on multilocus sequencing with 7 housekeeping genes, constructed using the CLC Genomics Workbench 5.0 UPGMA algorithm. The reference strains used are Mycobacterium abscessus ATCC 19977, Mycobacterium massiliense type strain CIP108297, and Mycobacterium bolletii type strain CIP108541.