Metagenomics analysis of bacteria in lameness cow foot lesions

Lameness represents an intractable problem for the dairy industry resulting in economic losses and seriously compromising animal welfare. Complicated claw horn disruption lesions; namely, complicated sole ulcers, complicated toe necrosis, and complicated white line disease, as well as interdigital hyperplasia and interdigital phlegmon are lameness causing lesions; their aetiology is not well described, but infectious processes are implicated in disease pathogenesis. The aim of the study was to investigate the microbiome profiles of these lesions using 16S rRNA gene amplicon sequencing of swab samples from the aforementioned lesions from 51 cattle across ten different dairy farms.In this study, interdigital hyperplasia (n=11), interdigital hyperplasia with signs of interdigital dermatitis (n=4), interdigital phlegmon (n=4), complicated sole ulcers (n=21), complicated toe necrosis lesions (n=3), and complicated white line lesions (n=11) were investigated; corresponding healthy skin control samples on the same farms were also analysed. All diseased tissues displayed reduced microbial diversity compared to their healthy skin control samples. In line with previous studies, our study indicates a role for Treponema spp for these disorders. Furthermore, other bacteria including Fusobacterium and Porphyromonas species were implicated in the aetiology of all these lesions with the exception of interdigital hyperplasia, and infected interdigital hyperplasia. Complicated claw horn disruption lesions, and interdigital phlegmon were identified as having similar microbiome contents. This finding suggests that many of the infectious agents detected in these foot lesions are acting opportunistically; this finding may help future treatments and/or control of these disorders