Minimum spanning tree of 56 Cmm strains based on eight VNTR loci. Each circle represents an MLVA type with a size corresponding to the number of strains that share an identical MLVA type. MLVA types connected by a thick solid line differ from one another by one VNTR locus, while MLVA types connected by a thin solid line differ by two VNTR loci. MLVA types that differ from each other by three, four or more VNTR loci are connected by dashed and dotted lines. MLVA types were distinguished to define clonal complexes and to group in zones MLVA types that differ from one another by at most two locus variants. Letters visible on each circle are corresponding to strains described in Table 1. CC-Clonal complex.