''Flavobacterium columnare'' is a thin

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

rod

bacterium Bacteria (; singular: 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 amon ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' Flavobacterium''. 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 uni ...

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 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 gram-positive bacilli and ...

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 inf ...

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

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

# binding of

Congo red Congo red is an organic compound, the sodium salt of 3,3′-( ,1′-biphenyl4,4′-diyl)bis(4-aminonaphthalene-1-sulfonic acid). It is an azo dye. Congo red is water-soluble, yielding a red colloidal solution; its solubility is greater in organic ...

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 contrast ...

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) is a symptom of disease in fish which results from an infection caused by the Gram-negative, aerobic, rod-shaped bacterium ''Flavobacterium columnare''. It was previously known as ''Bacillus columnaris, ...

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

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive ...

in the southeastern United States.

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