Dichelobacter nodosus and Fusibacterium necrophorum virulence andcross infection of foot rot in sheep and cattle.

摘要

Quantitative PCR assay to determine D. nodosus and F. necrophorumloads in ruminant foot-rot is described. Dichelobacter nodosus isolates from foot rot insheep and cattle were subjected to virulence test fimA, serogrouping and pulsed field gelelectrophoresis (PFGE). Virulent D. nodosus were serogroup B, intA positive and aprB2negative. F. necrophorum was found more frequently in feet contaminated by virulent D.nodosus. F. necrophorum subsp. necrophorum were detected in cross-infected foot rot andgreater loads of virulent D. nodosus and F. necrophorum were found in severe foot rot insheep grazing with cattle. D. nodosus loads were greater with interdigital dermatitis andsevere foot rot but were also isolated from normal animals. Multiple strains (serogroup) ofD. nodosus co-existed on individual feet during subclinical and clinical infections.