First molecular confirmation of Treponema spp. in lesions consistent with digital dermatitis in Chilean dairy cattle

Authors: SALGADO, MIGUEL ANGEL - Austral University Of Chile; CANALES, NIVIA - Austral University Of Chile; BUSTAMANTE, HEDIE - Austral University Of Chile; Wilson-Welder, Jennifer; THOMAS, CHRISTIAN - Austral University Of Chile; RAMIREZ, EMILIO - Austral University Of Chile

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2022
Publication Date: 4/26/2022
Citation: Salgado, M., Canales, N., Bustamante, H., Wilson-Welder, J.H., Thomas, C., Ramirez, E. 2022. First molecular confirmation of Treponema spp. in lesions consistent with digital dermatitis in Chilean dairy cattle. Pathogens. https://doi.org/10.3390/pathogens11050510.
DOI: https://doi.org/10.3390/pathogens11050510

Interpretive Summary: Digital dermatitis is a multi-bacterial skin lesion of cattle occurring at the hoof-skin junction most commonly on hind feet along the heel bulb or interdigital space. The lesions are painful, ulcerative and highly infectious within a herd. A significant cause of lameness, digital dermatitis cost producers world wide in terms of lost production, prevention and treatment, and animal welfare. While digital dermatitis has been clinically described in Chilean dairy cattle, the bacterial agents most commonly associated with digital dermatitis have not been identified. This study describes the use of a molecular PCR assay, to detect several species of the genus Treponema. Majority of the samples contained more than one species of Treponema. These findings are consistent with other studies conducted in other parts of the globe. While Chile may practice a combined grazing and housing system of dairy husbandry, the epidemiology and underlying bacterial pathogens are the same as in intensively house cattle in other countries. This has impact on future methods of prevention and treatment of this infectious and economically important disease.

Technical Abstract: Digital dermatitis (DD) is a highly contagious, infectious disease in cattle which has a considerable negative economic impact worldwide, and adversely affects animal welfare. Members of the genus Treponema are the only bacterial agents for which there is consistent evidence of participation in DD lesions. In Chile, DD has been described since the 1990s, but only under a clinical approach. To date, the presence of the pathogenic agent has not been confirmed in Chile by any type of confirmatory microbiological diagnosis. The aim of the present study was to confirm the presence of Treponema spp. in lesions consistent with DD, in Chilean dairy cattle for the first time. We provide PCR confirmation of Treponema spp. in Chilean dairy cattle affected by DD. The infection rate, as well as the proportion of the main Treponema species involved, is not different from that described in published studies elsewhere. Future herd control plans should benefit from the molecular confirmation of this serious infectious disease in cattle.