The MIRU-VNTR technique provides numerous advantages: it provides a rapid, adaptable technique to comment on selleck products the presence of clonal complexes within isolates linked using an epidemiological method [16]. Coding the results as a series of numbers allows an easy exchange of results between different labs. On the practical side, this

technique also enables evaluation of the possibility of laboratory contamination in cultures from different isolates. Using MIRU-VNTR markers, we also confirmed the identity of isolates collected from the same patients when they had a relapse of their illness. This stability was observed invitro with subcultures of the same isolate, and invivo for the same infected patient. This result contrasted with results obtained by the MIRU-VNTR technique on strains of M. tuberculosis, which provided an example of frequent exogenous infections [17]. We did not find any difference in the genetic profile of serial strains found in our patients, which permitted us to exclude the possibility of re-infection with a new strain of M. intracellulare. For the clustering analysis of MIRU-VNTR profiles, a graphing algorithm termed minimum spanning tree was used. This method has been introduced by some authors to improve Torin 2 supplier analysis of VNTR

profiles [14]. Similar to maximum-parsimony phylogenetic tree reconstruction methods, minimum spanning tree constructs a tree that connects all the genetic profiles Methane monooxygenase in such a way that the summed genetic distance of all branches is minimized. The differences in mathematical approach between minimum spanning tree and UPGMA methods explain changes in strains clustering. Thus, minimum spanning tree allowed us to group strains which were unclustered with UPGMA (isolates 54 in complex II and 34 in complex I). Our study permitted us to

characterize the statistical power of the MIRU-VNTR technique as applied to M. intracellulare. The global discriminatory index of 0.98 presented in this work confirmed the possible use of this technique, in agreement with results obtained with other species of the avium complex [7]. Interestingly, Ichikawa et al. [10] also described an HGDI of 0.98 for the MLVA of M. intracellulare. Forty-four MIRU-VNTR types were obtained in our study for the 61 M. intracellulare clinical isolates, a number similar to that described by Ichikawa [10]. Our results confirmed the data very recently described for M. intracellulare [10] showing that this method seemed to harbor a great discriminatory power for identification of genetically similar isolates. Mycobacterium avium-intracellulare complex agents, in addition to a broad host range, are environmental mycobacteria found in numerous biotopes including the soil, water, aerosols, and vegetation. Nevertheless, little is known about genetic variations among patient and environmental isolates of M. intracellulare.