英国の野生シカにおける家畜の跛行関連病原菌の保有状況

Lameness is one of the major diseases on UK farms and worldwide and can be caused by environmental damage and/or infection. The pathogens associated with infectious lameness, namely Fusobacterium necrophorum, Dichelobacter nodosus and pathogenic Treponema species are responsible for substantial economic losses. The lack of knowledge on reservoirs of these pathogens is concerning and wild deer may pose a potential risk for livestock infection. This study investigated the prevalence of lameness associated bacteria on the feet of culled wild deer using molecular methods and subsequent isolation to characterise bacteria and allow comparison to livestock pathogens. With the exception of Treponema medium, all the other pathogens were detected on deer feet with sika deer carrying the fewest pathogens and muntjac and roe carrying the most. Muntjac deer were significantly more likely than other deer species to carry F. necrophorum. Body condition score was a significant factor associated with pathogen carriage, with a higher body condition score leading to lower pathogen carriage. Identical treponemes based on 16S rRNA genes were isolated to those found in cattle and sheep. The assessment of the antimicrobials which the Treponema isolates were susceptible to, showed a high similarity to those previously reported in livestock, thus further suggesting carriage of similar bacteria. This study shows that wild deer within the UK are carriers for lameness bacteria but are asymptomatic. The infection risk which these wild ruminant ungulates pose to livestock species requires further research. This study begins to suggest a potential wildlife reservoir for lameness associated bacteria.