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Veterinary bacteriology: information about important bacteria
Veterinary bacteriology

Species/Subspecies: Fusobacterium necrophorum subsp. necrophorum
Category: Causes hemolysis
Etymology: Genus name: small spindle shaped rod.
Species epithet: necrosis producing.
Subspecies epithet: see Species epithet.
Significance:  [Very important]   
Alternative Species Name(s):Bacteroides necrophorus, Fusobacterium necrophorum (Biotyp A)
Type Strain: VPI 2891 = ATCC 25286 = CCUG 9994.
Macromorphology (smell):
Small cream-colored metal shiny colonies. Many strains produce an hemolysis zone on blood agar. Smells like rancid butter (or boiled cabbage). Colonies fluoresce in neon green under long-wave UV-light.
Micromorphology: Coccoid rods to thin, needle-shaped filaments. Non-motile.
Gram +/Gram -:
Metabolism: Strictly anaerobic
Other Enzymes: Esculinase -, lipase -, Tryptophanase + (= indole +).
Fermentation of carbohydrates: Butyric acid is produced by fermentation.
Spec. Char.: Temperature optimum: 37°C.
HostsDiseaseClinical picture
Cattle and sheepInterdigital dermatitisLame, fever, swollen hoof and sometimes also feedlock, sore, tender and foul-smelling hoof
Often mixed infection with other anaerobic bacteria or T. pyogenes

(Affect mostly calves)
Oral necrobacillosis

Calf diphtheria
Necrotic stomatitis, swollen ckeeks, damaged oral mucosa, can also affect the tongue, fever, anorexia and foul smell

Necrotic pharyngitis and laryngitis, difficulty to swallow, fever, salivation, respiratory distress, coughing and foul smell

Most often caused by sticky roughage or tooth loss
CattleLiver abscessesReduced weight gain, mostly diagnosed at slaughter, often secondary to rumenitis. Occasionally, rupture of abscess and perforation to vena cava could lead to infection of other organs and death
CattleMetritisInfection in uterus post-partum. Varies from inapparent infection to purulent exudate, often in association with T. pyogenes
Virulence Factors: Produces a leucotoxin directed against neutrophils and has LPS.
Genome Sequence:
Acc-noStrainSize (bp)Genome
Not reported    

16S rRNA Seq.:
Acc-noStrainNumber of NTOperon
AJ867039 ATCC 25286 1455  

Within the genus Fusobacteria, 14 species have been described and 2 of these are divided into 7 sub-species. Fusobacteria are related to genus Streptobacillus, but the latter belongs to another family, namely Leptotrichiaceae.
Comment:Can convert lactic acid to propionic acid.
Reference(s): No. 24


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Published 2023-03-01. Read more...
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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...

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