Mycobacterium avium subsp. hominissuis Infection in Swine Associated with Peat Used for Bedding

Figure 2

Minimum spanning tree (MST) analysis made in BioNumerics 6.1 illustrating the relatedness of isolates when more than one organ from the same pig was positive on culture for Mycobacterium avium subsp. hominissuis. All isolates () originating from 20 pigs were subjected for analysis. The figure illustrates the relationship and possible mutation pathways within the clusters based on single locus variations (SLV). The MST was created based on the MLVA data used for the cluster analysis of the complete dataset. The nodes (circles) consist of identical genotypes and the edges (lines) of weights based on number of mutations (steps) taken from the loci used. Long weights (steps) indicate multiple mutations, while short weights indicate few mutations. Isolates originating from the same pig are illustrated in the same color. The size of the nodes represents the number of isolates showing the same genotype, and the size of the colored fields represents the number of isolates from the same pig within the nodes. Each node is labelled with the letter describing the MLVA profile as shown in Figure 1. Mycobacterium avium subsp. avium ATCC 25291 was used as a reference strain.