Changes

==Distribution==

==Distribution==

Europe, North and South America and Australia.

Europe, North and South America, Africa, Asia and Australia.

ERM can be '''transmitted via water''' and it is poorly understood whether this is due to saprophytic function or merely prolonged survival in the presence of sediment and organic matter facilitating transmission and infection.<ref>Romalde, J. L., Barja, J. L., Magarinos, B., Toranzo, A. E (1994) '''Starvation-survival processes of the bacterial fish pathogen ''Yersinia ruckeri'''''. ''Systematic and Applied Microbiology'', 17:161-168</ref> The bacterium is '''shed in the faeces''' of infected fish and the quantity '''increases exponentially with stress'''. Once infected, a population can maintain the disease indefinitely.

ERM can be '''transmitted via water''' and it is poorly understood whether this is due to saprophytic function or merely prolonged survival in the presence of sediment and organic matter facilitating transmission and infection.<ref>Romalde, J. L., Barja, J. L., Magarinos, B., Toranzo, A. E (1994) '''Starvation-survival processes of the bacterial fish pathogen ''Yersinia ruckeri'''''. ''Systematic and Applied Microbiology'', 17:161-168</ref> The bacterium is '''shed in the faeces''' of infected fish and the quantity '''increases exponentially with stress'''. Once infected, a population can maintain the disease indefinitely.

The '''reddening of the throat and mouth''' that give the disease its name are caused by '''subcutaneous haemorrhage''' and are common but not always present. This can progress to '''erosion of the jaw and palate if untreated'''.

The '''reddening of the throat and mouth''' that give the disease its name are caused by '''subcutaneous haemorrhage''' and are common but not always present. This can progress to '''erosion of the jaw and palate if untreated'''.

Affected fish also have generally '''darkened skin and fins''' with haemorrhagic lesions around the '''gill tips, vent and fins and are lethargic and inappetant'''. They may have a '''distended abdomen''' leading to a “pot-bellied” appearance. Fish are often pale around the gills and may demonstrate '''exopthalmos''' with periorbital oedema. They may be seen to be swimming close to the surface.

Affected fish also have generally '''darkened skin and fins''' with haemorrhagic lesions around the '''gill tips, vent and fins and are lethargic and inappetant'''. They may have a '''distended abdomen''' leading to a “pot-bellied” appearance. Fish are often pale around the gills and may demonstrate '''exopthalmos''' with periorbital oedema. They are anorexic and may swim close to the surface.

'''Mortalities are frequent and variable. They may occur in small fry with virtually no preceding signs'''.<ref>Kawula, T. H., Lelivelt, M. J., Orndorff, P. E (1996) '''Using a new inbred fish model and cultured fish tissue cells to study '''Aeromonas hydrophila''' and '''Yersinia ruckeri''' pathogenesis'''. ''Microbial Pathogenesis'', 20(2):119-125; 12</ref> Losses of 15% over a cycle are not uncommon and can reach 90% on small scale units.

'''Mortalities are frequent and variable. They may occur in small fry with virtually no preceding signs'''.<ref>Kawula, T. H., Lelivelt, M. J., Orndorff, P. E (1996) '''Using a new inbred fish model and cultured fish tissue cells to study '''Aeromonas hydrophila''' and '''Yersinia ruckeri''' pathogenesis'''. ''Microbial Pathogenesis'', 20(2):119-125; 12</ref> Losses of 15% over a cycle are not uncommon and can reach 90% on small scale units.

'''Antibodies''' to ERM can be detected using '''[[Agglutination|latex agglutination]]''' and can also detect subclinical infections.<ref>Romalde, J. L., Magarinos, B., Fouz, B., Bandín, I., Núnez, S., Toranzo, A. E (1995) '''Evaluation of BIONOR mono-kits for rapid detection of bacterial fish pathogens'''. ''Diseases of Aquatic Organisms'', 21(1):25-34; 32</ref>

'''Antibodies''' to ERM can be detected using '''[[Agglutination|latex agglutination]]''' and can also detect subclinical infections.<ref>Romalde, J. L., Magarinos, B., Fouz, B., Bandín, I., Núnez, S., Toranzo, A. E (1995) '''Evaluation of BIONOR mono-kits for rapid detection of bacterial fish pathogens'''. ''Diseases of Aquatic Organisms'', 21(1):25-34; 32</ref>

The most recent method is '''PCR''' and is capable of detecting very low levels of ''Y. ruckeri'' but is insensitive and not commercially available.

The most recent method is '''PCR''' and is capable of detecting very low levels of ''Y. ruckeri'' but is insensitive and not commercially available. It is recommended that identification of pure cultures be based on amplification and sequencing of the 16S rRNA gene using universal bacterial primers 27F and 1492R.

At '''necropsy''', there is '''congestion of blood vessels''' throughout the peritoneum and white-grey patches of necrosis and '''petechial haemorrhages''' are found in the liver, swim bladder, pancreas, lateral muscles and adipose tissue. '''Serosanguinous fluid often accumulates''' in the body cavities and muscle which become yellow and mucoid within the intestinal tract. There may also be severe damage of the haematopoietic renal tissues.

At '''necropsy''', there is '''congestion of blood vessels''' throughout the peritoneum and white-grey patches of necrosis and '''petechial haemorrhages''' are found in the liver, swim bladder, pancreas, lateral muscles and adipose tissue. '''Serosanguinous fluid often accumulates''' in the body cavities and muscle which become yellow and mucoid within the intestinal tract. There may also be severe damage of the haematopoietic renal tissues.

==Treatment==

==Treatment==

ERM responds well to '''antibiotic treatment with oxolinic acid, oxytetracycline, sulphamerazine and tribrissen'''.  

ERM responds well to '''antibiotic treatment with oxolinic acid, oxytetracycline, sulphamerazine and tribrissen'''. '''Amoxicillin''' is now licenced for use in the UK.

'''Vaccines''' can also be used as treatments for infected fish.

'''Vaccines''' can also be used as treatments for infected fish.

==References==

==References==

<references/>

<references/>

{{CABI source

{{CABI source

|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=83811&loadmodule=datasheet&page=2144&site=160 enteric redmouth disease] and [http://www.cabi.org/ahpc/Default.aspx?site=160&page=2144&LoadModule=datasheet&CompID=3&dsID=59813 ''Yersinia ruckeri'']

|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=83811&loadmodule=datasheet&page=2144&site=160 enteric redmouth disease] and [http://www.cabi.org/ahpc/Default.aspx?site=160&page=2144&LoadModule=datasheet&CompID=3&dsID=59813 ''Yersinia ruckeri'']

|date =10 July 2011

|date =10 July 2011

}}

}}

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[[Category:Fish Diseases]]

[[Category:Fish Diseases]]

[[Category:CABI Expert Review]]

[[Category:CABI Expert Review]]