Bovine metagenome digital dermatitis Metagenome. Bovine metagenome digital dermatitis

Digital dermatitis (DD) is the leading cause of infectious lameness in dairy cattle globally. While research efforts to find effective treatment and control regimes have increased recently, eradicating the disease is complicated by unclear etiology and symptom relapses. It is widely accepted that DD is a polymicrobial disease and the non-linear disease progression may be attributed, in part, to interactions among infecting bacteria. Multiple species of Treponema are consistently isolated from DD and previous studies have shown bacterial diversity and community shifts are associated with lesion stages. We postulated the morphological changes associated with M-stage DD lesions are related to interactions among infecting species of Treponema. To study this association, we developed a novel species-specific qPCR that can identify four of the most common species of Treponema, T. phagedenis, T. medium, T. pedis and T. denticola and their absolute quantities per mg of tissue in a single reaction. In addition, we used highthroughput 16S rRNA gene sequencing (V1-V2 hypervariable regions) to validate the result of our qPCR assay and explore the association between DD and microbial diversity.