Fig 2.

Minimal spanning tree based on MLST alleles. Each ST is indicated by a circle encompassing the ST number, whose size reflects the number of isolates; eBGs are indicated by gray shading around STs, and the eBG designation is within a rectangle. STs are connected by thick black lines (six identical alleles) or thin black lines (five identical alleles). The primary connecting lines are not terminated, but two alternative connections at the level of five identical alleles are indicated by lines terminating in bars. All STs that are unconnected shared fewer than four alleles.