FIG. 1.

Minimum spanning tree of MLST and MLVA of N. meningitidis isolates obtained from 85 Dutch patients with invasive meningococcal disease and seven reference strains. Each circle denotes a particular MLST or MLVA type, and the size of the circle indicates the number of isolates of that particular type. Thick, solid lines denote connections between single-locus variants; thin, solid lines denote double-locus variants; dotted lines indicate types that differ in more than two loci. The letter within the circle represents the serogroup of the strains with this type. The colors of the circles in the MLST and MLVA trees indicate the MLST clonal complexes as designated on the MLST website (http://pubmlst.org/neisseria). The clonal complexes are also indicated outside the circles in the minimum spanning tree of the MLST. The white circles denote STs for which no clonal complex has been assigned on the MLST website. The halos surrounding the various types denote the groupings obtained by Bionumerics analysis. In Bionumerics MLST, groups (complexes) were created if neighbors differed in no more than two of the seven alleles. MLVA grouping was achieved if neighbors differed in no more than one of the eight VNTR loci. The red halos in the MLVA tree denote three MLVA groups that were not present as separate MLST groups. Two of these groups are made up of isolates belonging to the ST-11 clonal complex. The other MLVA group with a red halo is composed of an MLST ST-254 isolate and an ST-41/44 isolate.