VetBact logo


Swedish University of Agricultural Sciences

Veterinary bacteriology: information about important bacteria
Veterinary bacteriology

Species/Subspecies: Dichelobacter nodosus
Category: Motile
Etymology: Genus name: rod shaped (bacterium) in ungulates.
Species epithet: full of knots (refers to the shape of the cells).
Significance:The disease causes economic losses and animal suffering in large parts of the world.
  [Very important]   
Alternative Species Name(s):Bacteroides nodosus
Type Strain: ATCC 25549 = CCUG 27824.
Macromorphology (smell):
Small (0.5-3.0 mm in diameter) translucent grayish white colonies after 3-7 days. Grows slowly and the colonies are difficult to see. Gives no hemolysis on FAA plates.
Straight or curved rods (1-1.7 x 3-6 µm) with rounded and enlarged ends. Has twitching motility by means of type IV pili.
Gram +/Gram -:
Metabolism: Strictly anaerobic
Other Enzymes: DNase -, esculinase -, ornithine decarboxylase +, tryptophanase (indole) -, urease -.
Biochemical Tests: H2S +
Fermentation of carbohydrates: D. nodosus does not ferment carbohydrates.
Spec. Char.:
Special Media: Hoof agar is often used for isolation of D. nodosus.
HostsDiseaseClinical picture
SheepFootrotContagious hoof disease, often synergistic with other bacteria e.g. F. necrophorum. Begins as a mild inflammation, interdigital dermatitis.
Lame, standing on carpus while grazing and reduced production.
Mild (benign) form limited to the interdigital skin. Severe form (virulent) infect deeper tissues.
Virulence Factors: Type IV pili (fimbriae) which give the bacteria motility in damaged tissue. Extracellular serine protease which makes it possible for the bacterium to digest the tissue of the host animal to get access to free amino acids.
Diagnostics:Gram staining of clinical material, microscopy, culture and confirmation by PCR or MALDI-TOF MS. Benign strains can be differentiated from virulent ones by PCR.
Genome Sequence:
Acc-noStrainSize (bp)Genome
NC_009446 VCS1703A 1 389 350  

16S rRNA Seq.:
Acc-noStrainNumber of NTOperon
DQ016290 AN 363/05 1437 

Only one species has been described within genus Dichelobacter and this species is related to species within genus Stenotrophomonas.
Reference(s): No. 2, 39, 127


New names of bacterial phyla

The taxonomic category phylum was previously not regulated by the International Code of Nomenclature of Prokaryotes (ICNP), but now this has changed and it was decided to revise the names of bacterial phyla. All phyla must be written in italics (which has been done on VetBact also before) and have the ending -ota.

Published 2023-03-01. Read more...
The taxonomy of chlamydias

Species within the family Chlamydiaceae were previously divided into two genera Chlamydia and Chlamydophila. However, the differences between these two genera were not that great and many research groups have not accepted this division. Therefore, the genus Chlamydophila has been returned to the genus Chlamydia and this change has now been incorporated in VetBact

Published 2023-03-15. Read more...

Recently Updated

Recent blog posts

Most recent comment

Swedish University of Agricultural Sciences