Current understanding of the aetiology and laboratory diagnosis of footrot

• Published in: The veterinary journal (1997) 2006-05, Vol.171 (3), p.421-428
• Main Authors: Wani, S.A., Samanta, I.
• Format: Article
• Language: English
• Subjects: animal pathogenic bacteria; Animals; Antigenic Variation; bacterial antigens; diagnostic techniques; Dichelobacter nodosus; Dichelobacter nodosus - genetics; Electrophoresis, Gel, Pulsed-Field; fimbriae; Foot Rot - diagnosis; Foot Rot - microbiology; Foot Rot - transmission; Footrot; goat diseases; Goat Diseases - diagnosis; Goat Diseases - microbiology; Goat Diseases - transmission; Goats; Gram-Negative Bacterial Infections - diagnosis; Gram-Negative Bacterial Infections - microbiology; Gram-Negative Bacterial Infections - transmission; Gram-Negative Bacterial Infections - veterinary; literature reviews; microbial genetics; molecular sequence data; nucleotide sequences; pathogen identification; PCR; PCR-RFLP; PFGE; polymerase chain reaction; Polymerase Chain Reaction - veterinary; Polymorphism, Restriction Fragment Length; serotypes; Sheep; sheep diseases; Sheep Diseases - diagnosis; Sheep Diseases - microbiology; Sheep Diseases - transmission; strain differences; strains; virulence
• ISSN: 1090-0233; 1532-2971
• DOI: 10.1016/j.tvjl.2005.02.017

Footrot is a highly contagious disease of the feet of ruminants caused by the synergistic action of certain bacterial species of which Dichelobacter nodosus ( D. nodosus) is the main transmitting agent. The infection is specific to sheep and goats, although it has also been reported in cattle, horses, pigs, deer and mouflon. The antigenic diversity of D. nodosus is due to variations in the DNA sequence of its fimbrial subunit gene ( fimA) and provides the basis for classification of the organism into at least 10 major serogroups (A–I and M), the distribution of which varies with different geographical locations. Host immune response to vaccination is serogroup specific. There are three different clinical forms of disease caused by virulent, intermediate and benign strains of D. nodosus, respectively. In order to facilitate rapid and reliable clinical diagnosis, virulence determination, strain differentiation and serogroup identification for effective control measures, immunological tests, DNA probes and PCR based techniques have been introduced. This review summarises the current understanding of the mechanisms of antigenic diversity of D. nodosus as well as advances made in its strain differentiation and diagnosis.