spp. Isolated from Bovine Digital Dermatitis Display Different Pathogenicity in a Murine Abscess Model.

Digital dermatitis (DD) causes lameness in cattle with substantial negative impact on sustainability and animal welfare. Although several species of bacteria have been isolated from various DD stages, their individual or synergistic roles in the initiation or development of lesions remain largely unknown. The objective of this study was to compare effects of the three most common species isolated from DD lesions in cattle (), both as individual and as mixed inoculations, in a murine abscess model. A total of 10 or 5 × 10 spp. were inoculated subcutaneously, and produced abscess was studied after 7 days post infection. There were no synergistic effects when two or three species were inoculated together; however, produced the largest abscesses, whereas those produced by were the smallest and least severe. species were cultured from skin lesions at 7 days post infection and, additionally, from the kidneys of some mice (2/5), confirming systemic infection may occur. Taken together, these findings suggest that and may have more important roles in DD lesion initiation and development than .