Figure 3

Minimum spanning tree for the 40 Malaysian Shigella sonnei strains and strains from five other countries. For Malaysian strains, each circle represents one strain with a unique MLVA profile. Each circle is noted with the MLVA type of the strain. MLVA types in yellow colour are Malaysian biotype g strains whereas those in green are Malaysian biotype a strains. For the profiles of strains from five other countries, the circle size is not proportional to the number of strains belonging to the MLVA profile but it is proportional to the number of outbreaks or unrelated episodes sharing the same profile. Circles in grey colour denote global clonal group A, orange denotes group B, and blue denotes group C. Additional information on these foreign strains is provided [see Additional file 1]. The distance between two MLVA types is numbered. A distance of one locus between two closest MLVA types is marked by a thick black line, a distance of two loci is marked by a blue line, and a distance of three loci is indicated by a thin red line. A distance of four loci is indicated by a broken line and a distance of five loci is indicated by a light broken line.