Virulence phenotypes are indicated after the strain designation. Abbreviations: NC, no colonization; C, colonization with no enteritis; E, colonization with enteritis; HE, colonization with hemorrhagic enteritis; CN, colonization with neurological signs but no enteritis; EN, colonization with enteritis; HEN, colonization with hemorrhagic enteritis and neurological signs. Hamming distance with UPGMA clustering; bootstrap support values (% of 1000 runs) are shown for all nodes. Panel A, Genome-sequenced strains. Panel B, strains analyzed by microarray.