Bovine digital dermatitis (
BDD) is an infective
foot disease commonly reported in dairy cattle where Treponema are considered as the primary causative infectious agents. There still remains little definitive information on the etiology of
BDD in beef cattle suggesting further investigations are warranted. Beef
BDD lesions (n=34) and healthy beef foot tissues (n=38) were analysed by PCR for three
BDD-associated Treponema phylogroups and also for Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was attempted on all
BDD lesion samples. One or more
BDD-associated Treponema phylogroups were detected in 100% of beef
BDD lesions. "Treponema medium/Treponema vincentii-like", "Treponema phagedenis-like" and Treponema pedis spirochetes were identified in 27/34 (79%), 31/34 (91%) and 24/34 (71%) of
BDD lesions, respectively. No
BDD-associated treponeme
DNA was amplified from beef healthy foot tissues. D. nodosus and F. necrophorum were present in 24/34 (71%) and 15/34 (44%) of lesions and 10/38 (26%) and 12/38 (32%) of healthy foot tissues, respectively. Twenty spirochetes were isolated from beef
BDD lesions; 19 were representatives of the three
BDD-associated Treponema phylogroups. One spirochete isolate shared less than 97%
16S rRNA gene similarity to the three cultivable
BDD-associated Treponema phylogroups and therefore may represent a novel taxa of Treponema. Upon comparison, sheep contagious
ovine digital dermatitis (CODD), dairy cattle and beef cattle
BDD lesions appear to have extremely similar bacteriological data and therefore provides evidence of a shared etiopathogenesis posing concerns for cross-species transmission.