Figure 1

Minimum spanning tree of 240 S . Enteritidis strains based on MLVA. The categorical coefficient and the highest number of single-locus-changes have been used for the construction. Each circle represents one MLVA type. The numbers in the circles indicate the corresponding phage type(s) of the strain(s). Bold short lines link MLVA types differing by one allele. Thin lines link MLVA types with two different alleles and bold dotted lines connect types different by three alleles and thin dotted lines differ in four alleles. The different colors of the circles indicate the number of strains with a particular MLVA type: light blue circles 1 to 2 strains, turquoise circles 3 to 5 strains, purple circles 6 to 10 strains, red circles 11 to 50 strains. The green cluster represents isolates of the phage type 11 having a maximum distance of changes for three alleles.