Characterization of the Predominant Anaerobic Bacterium Recovered from Digital Dermatitis Lesions in Three Michigan Dairy Cows

Digital dermatitis is a superficial epidermatitis of the feet of cattle. Data from previous work suggest that spirochaetes, Campylobacter spp., and Bacteroides spp. may be important in the disease, but the etiology of this disease is not entirely clear. Tissue samples collected from digital dermatitis lesions in three Holstein-Friesian cows from a Michigan dairy yielded a predominant colony type when incubated anaerobically on blood agar at 35 degrees C for 24-48 h. The isolate was a non-flagellated Gram-negative rod, 7 microM long and <0.5 microM wide; its growth was strictly anaerobic and resulted in slight ss-hemolysis on blood agar; 16S rRNA gene sequence analysis indicated it belonged to the cytophoga-flexibacter-bacteroides phylum. The finding that this bacterium was the predominant anaerobe recovered from digital dermatitis lesions suggests it may be involved in the digital dermatitis disease process.