FIG. 4.

Minimum spanning tree of S. flexneri isolates based on PFGE data. The tree was constructed based on the presence or absence of PFGE bands. Pulse types with a band difference of one are connected by a thick line while those with a difference of two are connected by a thin line and those with a difference greater than two are connected by a dashed line. Clonal complexes are shaded. Each pulse type is color coded by serotype(s), and the pulse type is labeled alongside the circle. The circle size is proportional to the number of serotypes in the given pulse type.