A phylogenetic tree of 16S rRNA gene sequence similarity, showing the position of the six clones belonging to Gammaproteobacteria found in Horse 50L and the most closely related type strains belonging to the Escherichia genus. The six clones (acc.no. GQ423062) had 100% similarity to Shigella flexneri and E. fergusonii. Enterobacter sakazakii (AB004746) was used as an outgroup. Sequence accession numbers are presented.