''Flavobacterium columnare'' is a thin

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

rod

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Flavobacterium ''Flavobacterium'' is a genus of Gram-negative, nonmotile and motile, rod-shaped bacteria that consists of 130 recognized species. Flavobacteria are found in soil and fresh water in a variety of environments. Several species are known to cause ...

''. The name derives from the way in which the organism grows in

rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be un ...

columnar formations. The species was first described by Davis (1922), and the name was validated by Bernardet and Grimont (1989). ''Flavobacterium columnare'' can be identified in the laboratory by a five-step method that demonstrates: # the ability to grow on a medium containing

neomycin Neomycin, also known as framycetin, is an aminoglycoside antibiotic that displays bactericidal activity against Gram-negative aerobic bacilli and some anaerobic bacilli where resistance has not yet arisen. It is generally not effective against ...

and

polymyxin B Polymyxin B, sold under the brand name Poly-Rx among others, is an antibiotic used to treat meningitis, pneumonia, sepsis, and urinary tract infections. While it is useful for many Gram negative infections, it is not useful for Gram positive infe ...

# production of yellow pigmented rhizoid (root-like in appearance) colonies # production of a gelatin-degrading

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

# binding of Congo red dye to the colony # production of a

chondroitin A chondroitin is a chondrin derivative. Types include: * Chondroitin sulfate * Dermatan sulfate Chondroitin as a supplement is now commonly used (often in combination with glucosamine) in treating the joint disease of osteoarthritis. In contra ...

sulfate-degrading enzyme The species has been known previously as ''Flexibacter columnaris'', ''Bacillus columnaris'', and ''Cytophaga columnaris''. ''Flavobacterium columnare'' is one of the oldest known diseases among warm-water fish, and manifests itself as an infection commonly known as

columnaris Columnaris (also referred to as cottonmouth and saddle-back disease) is a disease in fish which results from an infection caused by the Gram-negative, aerobic, rod-shaped bacterium '' Flavobacterium columnare''. It was previously known as ''Bacill ...

. Infections are the second leading cause of mortality in pond raised

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

in the southeastern United States. Early treatment with potassium permanganate has been shown to increase survival rate, although the difference was not statistically significant.

References

External links

Type strain of ''Flavobacterium columnare'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Bacterial diseases of fish columnare Bacteria described in 1989 {{Flavobacteria-stub