Dendrogram of PFGE patterns of 11 B. pilosicoli hipp− and 9 B. pilosicoli field isolates, B. pilosicoli P43/6/78 type strain, and B. hyodysenteriae B204 reference strain. ✽, the number of nucleotide differences in the 16S rDNA between field isolates and B. pilosicoli P43/6/78 type strain is in parentheses. B. pilosicolihipp−, B. pilosicoli, hipp−.