avian & livestock assay data sheet
B0093 - Ultrasensitive detection of Fusobacterium necrophorum by real time PCR
Fusobacterium organisms are anaerobic,
non-motile, gram-negative bacilli. The genus includes F.
necrophorum, F. nucleatum, F. mortiferu, F. varium, F.
gonidaformans, F. alocis, F. pseudonecrophorum, F. salci,
and F. ulcerans. Members of this genus usually appear
as slender or fusiform rods with tapered ends under microscope.
However, some species may be pleomorphic in shape.
Fusobacteria are normal inhabitants of mucosal
surfaces, including the mouth, upper respiratory tract,
gastrointestinal tract, and urogenital tract. F. nucleatum
is the most commonly identified Fusobacterium, but F.
necrophorum is the most virulent species. Fusobacteria are
generally susceptible to penicillin, clindamycin, and
chloramphenicol, and resistant to erythromycin and macrolides.
F. necrophorum can cause various
diseases in domestic animals. It is known to be associated with
bucket feeding because feeding buckets are often contaminated
with feces. These bacteria can enter through abrasions in the
mucosa of the pharynx and larynx and cause fever, depression,
anorexia, salivation, respiratory distress and halitosis.
Aspiration of necrotic material into lungs may cause fatal
In cattle, F. necrophorum can cause calf
diphtheria or necrotic laryngitis, and necrobacillosis of the
mouth and pharynx of young calves. More severe infections may
involve bovine liver abscesses and localized necrosis and scab
formation of the teat orifice and sphincter of cows. It is also
associated with metritis in dairy cows (Bicalho et al., 2012).
In pigs, F. necrophorum may cause necrotic rhinitis
whereas in sheep, it can cause interdigital dermatitis in
association with D. nodosus and Acranobacter pyogenes. It also
causes laryngeal chondritis in sheep and mixed infections in
F. necrophorum is difficult to grow in
culture and often requires selective media with subsequent
phenotypic characterization. Molecular detection by polymerase
chain reaction (PCR) is highly specific, sensitive, and rapid.
Thus, molecular method is a good alternative to traditional
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
Help ensure that herds are free of this bacterium
Early prevention of spread of this bacterium
Minimize human exposure to this bacterium
Safety monitoring of biological products that derive from
Bicalho, M.L., Machado, V.S., Oikonomou, G., Gilbert, R.O. and
Bicalho, R.C. (2012) Association between virulence factors of
Escherichia coli, Fusobacterium necrophorum, and Arcanobacterium
pyogenes and uterine diseases of dairy cows. Vet. Microbiol.
Nasopharyngeal swabs, or fecal swabs, or 0.2 ml feces, or 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
tube, or 0.2 ml fresh, frozen
or fixed tissue.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
real time PCR