Changes

==Introduction==

==Introduction==

'''''Edwardsiella ictaluri''''' belongs to the '''''Enterobacteriaceae''''' family and is a '''Gram negative''', short, pleomorphic '''rod''', measuring 0.75 × 1.5-2.5 µm, which is '''weakly motile''' at 25-30°C, but not at higher temperatures.  It has peritrichous flagella and occasionally pili that can be seen with a scanning electron micrographs and can have between one to three '''plasmids''' depending on their molecular mass.  It is generally considered an '''obligate pathogen''', although it can survive in steralised pond bottom mud for over 90days but does not compete well with other microbes.   

'''''Edwardsiella ictaluri''''' belongs to the '''''Enterobacteriaceae''''' family and is a '''Gram negative''', short, pleomorphic '''rod''', measuring 0.75 × 1.5-2.5 µm, which is '''weakly motile''' at 25-30°C, but not at higher temperatures.  It has peritrichous flagella and occasionally pili that can be seen with a scanning electron micrographs and can have between one to three '''plasmids''' depending on their molecular mass.  It is generally considered an '''obligate pathogen''', although it can survive in steralised pond bottom mud for over 90days but does not compete well with other microbes.  The organism is lactose negative, catalase-positive, cytochrome oxidase-negative, glucose fermentative and reduces nitrate to nitrite <ref name="Shotts and Teska, 1989">Shotts, E.B., Teska, J.D., (1989)  '''Bacterial pathogens of aquatic vertebrates'''. In: Austin B, Austin DA, eds. ''Methods for the Microbiological Examination of Fish and Shellfish'''. Chichester, UK: Ellis Horwood, 164-186.</ref>.

 

''E. ictaluri'' '''affects fish species only''' and '''causes enteric septicaemia of catfish (ESC)''' and various other species of fish.  ESC is considered one of the '''most important infectious disease''' problems in the '''commercial catfish industry''' in the '''USA'''.  '''''E..tarda''''' causes '''Edwardsiella septicemia (ES)''' which is also known as '''fish gangrene, emphysematous putrefactive disease of catfish''' or '''red disease in eels''' and it '''can affect other animals'''.  Whereas '''''E. hoshinae''' infects birds and reptiles'''.  

''E. ictaluri'' '''affects fish species only''' and '''causes enteric septicaemia of catfish (ESC)''' and various other species of fish.  ESC is considered one of the '''most important infectious disease''' problems in the '''commercial catfish industry''' in the '''USA'''.  '''''E..tarda''''' causes '''Edwardsiella septicemia (ES)''' which is also known as '''fish gangrene, emphysematous putrefactive disease of catfish''' or '''red disease in eels''' and it '''can affect other animals'''.  Whereas '''''E. hoshinae''' infects birds and reptiles'''.  

Within '''channel catfish''' species the bacteria causes '''two forms of ESC'''; an '''acute septicaemia''' and '''chronic encephalitis'''.  In the latter form the infection spreads from the olfactory sacs, and migrates along the olfactory nerves to the brain, generating granulomatous inflammation.  In the acute form of ESC  the disease is thought to develop from the intestinal mucosa causing a bacteremia.  

Within '''channel catfish''' species the bacteria causes '''two forms of ESC'''; an '''acute septicaemia''' and '''chronic encephalitis'''.  In the latter form the infection spreads from the olfactory sacs, and migrates along the olfactory nerves to the brain, generating granulomatous inflammation.  In the acute form of ESC  the disease is thought to develop from the intestinal mucosa causing a bacteremia.