FIG 1.
Minimum spanning tree analysis of 126 blaCTX-M-positive Escherichia coli isolates based on MLST genotypes. Each circle represents a genotype, and the partitions within a circle are individual isolates. There are three main clonal complexes, and each is surrounded by a gray zone. Thick lines connect genotypes that differ at one locus, and thin lines connect genotypes that differ by two or more loci. Shading indicates the region from which isolates were obtained: pale gray indicates eastern Washington (n = 78) and dark gray indicates northwestern Washington (n = 48).