Enteric redmouth disease, or simply redmouth disease is a

bacterial infection Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of ...

of freshwater and marine

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

caused by the pathogen ''

Yersinia ruckeri ''Yersinia ruckeri'' is a species of Gram-negative bacteria, known for causing enteric redmouth disease Enteric redmouth disease, or simply redmouth disease is a bacterial infection of freshwater and marine fish caused by the pathogen ''Yersinia ...

''. It is primarily found in

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...

(''Oncorhynchus mykiss'') and other cultured

salmonids Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefi ...

. The disease is characterized by subcutaneous hemorrhaging of the mouth, fins, and eyes. It is most commonly seen in

fish farms upright=1.3, Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye">mariculture.html" ;"title="Salmon farming in the sea (mariculture">Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye, Scotland Fish farming or ...

with poor water quality. Redmouth disease was first discovered in Idaho rainbow trout in the 1950s.LSC – Fish Disease Leaflet 82
The disease does not infect humans.

Distribution of disease

Some fish species serve as vectors for the disease and have subsequently spread the pathogen to other parts of the world. An example is the

fathead minnow Fathead minnow (''Pimephales promelas''), also known as fathead or tuffy, is a species of temperate freshwater fish belonging to the genus ''Pimephales'' of the cyprinid family. The natural geographic range extends throughout much of North Ameri ...

(''Pimephales promelas'') which is responsible for the spread of redmouth disease to trout in Europe. Other vectors include the

goldfish The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have ...

(''Carassius auratus''), Atlantic and Pacific

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

(''Salmo salar''), the

emerald shiner The emerald shiner (''Notropis atherinoides'') is one of hundreds of small, silvery, slender fish species known as shiners. The identifying characteristic of the emerald shiner is the silvery emerald color on its sides. It can grow to 3.5 ...

(''Notropis atherinoides''), and farmed whitefish (''Coregonus'' spp.). Infections have also occurred in farmed

turbot The turbot (''Scophthalmus maximus'') is a relatively large species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the Northeast Atlantic, Baltic Sea and the Mediterranean Sea. It is an im ...

(''Scophthalmus maximus''), seabass (''Dicentrarchus labrax''), and

seabream The Sparidae are a family of fish in the order Perciformes, commonly called sea breams and porgies. The sheepshead, scup, and red seabream are species in this family. Most sparids are deep-bodied compressed fish with a small mouth separated by a ...

(''Sparus auratus''). It can now be found in North and South America, Africa, Asia, and Australia, as well as Europe.

Clinical signs and diagnosis

Infection can cause subcutaneous

haemorrhage Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vagi ...

that presents as reddening of the throat, mouth, gill tips, and fins, and eventual erosion of the jaw and palate. Hemorrhaging also occurs on internal organs, and in the later stages of the disease, the abdomen becomes filled with a yellow fluid - giving the fish a "pot-bellied" appearance. The fish often demonstrate abnormal behavior and anorexia. Mortality rates can be high. A presumptive diagnosis can be made based in the history and clinical signs, but definitive diagnosis requires

bacterial culture A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagn ...

and serological testing such as

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence ...

and

latex agglutination A latex fixation test, also called a latex agglutination assay or test (LA assay or test), is an assay used clinically in the identification and typing of many important microorganisms. These tests use the patient's antigen-antibody immune respon ...

Treatment and control

Several

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...

are available for the treatment of redmouth disease in fish.

Vaccines A vaccine is a biological preparation that provides active acquired immunity The adaptive immune system, also known as the acquired immune system, is a subsystem of the immune system that is composed of specialized, systemic cells and pro ...

can also be used in the treatment and prevention of disease. Management factors such as maintaining water quality and a low stocking density are essential for disease prevention.

References

External links

Enteric redmouth - The Scottish Government: Marine and Fisheries
*Enteric Redmouth Disease, reviewed and published by

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at http://en.wikivet.net/Enteric_Redmouth_Disease, accessed 08/09/2011. Bacterial diseases of fish Fish farming {{veterinary-med-stub