Nusieve agarose

MIRU-VNTR typing was performed by PCR amplification of the following 15 loci, as described by Supply et al. [28] (link): 424, 577, 580, 802, 960, 1644, 1955, 2163, 2165, 2401, 2996, 3192, 3690, 4052, and 4156. The PCR fragments were analyzed by gel electrophoresis using 2% NuSieve agarose (Cambrex Bio Science Rockland). For each locus, sizes of amplicons were estimated by comparison with 20 bp and 100 bp markers (Superladder-low; GenSura, CA, USA) and the numbers of repetitive units were calculated on the basis of conventions previously reported [31] (link). MIRU-VNTR profile is expressed as a string of 15 numbers, each representing the number of tandem repeats (TR) at a given VNTR position, in the order given above. MIRU-VNTR data were analyzed by the MIRU-VNTRplus web application available at www.miru-vntrplus.org[32] (link)–[33] (link).

Genomic DNA was extracted by the cetyltrimethyl-ammonium bromide (CTAB) method. VNTR typing was performed by PCR using specific primers for 16 M. intracellulare VNTR loci, as described previously [10 (link)]. The PCR fragments were analyzed by gel electrophoresis using 2% NuSieve agarose (Cambrex Bio Science Rockland). For each locus, sizes of amplicons were estimated by comparison with 20 bp and 100 bp markers (Superladder-low; GenSura, CA, USA. VNTR profile is expressed as a string of 16 numbers, each representing the number of tandem repeats (TR) at a given VNTR position.