Cross-infection of virulent Dichelobacter nodosus between sheep and co-grazing cattle.
Dichelobacter nodosus is the main aetiological agent of ovine footrot and the bacterium has also been associated with interdigital dermatitis is cattle. The aim of this study was to investigate possible cross-infection of virulent D. nodosus between sheep and co-grazing cattle. Five farms, where sheep previously diagnosed with virulent D. nodosus were co-grazing with cattle for different periods of time, were included. The study sample consisted of 200 cows and 50 sheep. All cows were examined for the presence of interdigital dermatitis, and ten ewes, preferably with symptoms of footrot, had the footrot scores recorded. On each farm, the same ten ewes and ten cows were chosen for bacterial analyses. Swabs were analysed for D. nodosus by PCR and culturing. D. nodosus isolates were virulence-tested and assigned to serogroups by fimA variant determination. Biopsies were evaluated histopathologically and analysed by fluorescent in situ hybridization for D. nodosus, Treponema spp. and Fusobacterium necrophorum. D. nodosus defined as virulent by the gelatin gel test were isolated from 16 sheep from four farms and from five cows from two of the same farms. All five cows had interdigital dermatitis. Two of the cows stayed infected for at least eight months. By pulsed-field gel electrophoresis (PFGE), the isolates from the five cows were found to be genetically indistinguishable or closely related to isolates from sheep from the same farm. This indicates that cross-infection between sheep and cows have occurred.
['Knappe-Poindecker|Maren|M|', 'Gilhuus|Marianne|M|', 'Jensen|Tim K|TK|', 'Vatn|Synnøve|S|', 'Jørgensen|Hannah J|HJ|', 'Fjeldaas|Terje|T|']
D000818:Animals D002417:Cattle D002418:Cattle Diseases D020376:Dichelobacter nodosus D016521:Electrophoresis, Gel, Pulsed-Field D005535:Foot Rot D005674:Fusobacterium Infections D005675:Fusobacterium necrophorum D016905:Gram-Negative Bacterial Infections D016133:Polymerase Chain Reaction D012756:Sheep D012757:Sheep Diseases D014208:Treponema D014211:Treponemal Infections
Cross-infection Dichelobacter nodosus Sheep Cattle