FIG. 3.

Phylogenetic relationships of mutS nucleotide sequences from pathogenic E. coli and S. dysenteriae type 1. The tree shown represents the strict consensus of three equally parsimonious trees and has a tree length of 171 steps (CI = 0.71, RI = 0.89). Measures of clade confidence are reported in italics below each node in the form of bootstrap values. Individual branch lengths are presented above each branch, and the numbers of unambiguous substitutions that mapped to the tree only once are given in parentheses. The brackets to the right of the tree indicate the six distinct clades of pathogenic strains (1 to 6). The nearest ECOR strain(s) based on mutS relationships and the MLEE ECOR group designation is listed to the right of each bracketed clade.