Dichelobacter nodosus
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| Also known as: | D.nodosus |
D.nodosus is formerly known as Bacteroides. It is a pathogenic, anaerobic, non-spore-forming Gram-negative bacteria. It causes footrot in sheep, along with other bacteria.
Characteristics
D.nodosus are large rods with terminal swellings. They have long, polar fimbriae. There are 16 antigenic types of fimbriae, which can be used to differentiate strains antigenically. All of the strains possess the same O antigen. Colonies of virulent strains have a dark central zone, a pale granular middle zone and an irregular periphery.
Pathogenesis
Thermostable proteases and elastase contribute to the pathogenesis of D.nodosus. Keratinolytic proteases are required for virulence and fimbriae are required for adhesion to hoof.
D.nodosus is a primary pathogen of epidermal tissues of the hoof of ruminants, suriving briefly in the envionment. It can be passed from animal to animal.
Immunity
A Homologous antibody to the fimbrial antigen prevents adhesion and protects against D.nodosus. The antibody must penetrate the epidermal layers and reach adequate concentration on the skin surface. A vaccine is available against D.nodosus. Strains can be detected by ELISA and PCR.
For more information on Contagious Footrot.