Changes

==Pathology==  

==Pathology==  

Histological examination reveals a systemic infection of all organs and skeletal muscles, with the most severe changes being diffuse interstitial necrosis of the anterior and posterior kidney and systemic haemorrhages. Focal necrosis in the liver and spleen are also generally seen as pale grey/white lesions.  Skeletal muscle and areas of necrosis within internal organ tissue can be infiltrated with macrophages, that phagocytose the bacteria but do not destroy it (Miyazaki and Plumb, 1985; Klesius et al., 1991; Klesius, 1993;).

'''Histological examination''' reveals a '''systemic infection of all organs''' and '''skeletal muscles''', with the most severe changes being '''diffuse interstitial necrosis''' of the anterior and posterior '''kidney and systemic haemorrhages'''. '''Focal necrosis in the liver'' and '''spleen''' are also generally seen as '''pale grey/white lesions'''.  Skeletal muscle and areas of necrosis within internal organ tissue can be '''infiltrated with macrophages''', that phagocytose the bacteria but do not destroy it (Miyazaki and Plumb, 1985; Klesius et al., 1991; Klesius, 1993;).

==Diagnosis==

==Diagnosis==

Clinical signs are quite pathognomonic for E.ictaluri but PCR is used to confirm the presence of E. ictaluri in blood and tissues but other methods have been used such as indirect FAT (detecting antibodies) and ELISA test.

'''Clinical signs''' are quite '''pathognomonic''' for E.ictaluri but '''PCR''' is used to confirm the presence of E. ictaluri in blood and tissues but other methods have been used such as '''indirect FAT (detecting antibodies)''' and '''ELISA''' test.

The organism is slow growing and forms small, translucent, greenish colonies on Edwardsiella isolation media (EIM), while inhibiting Gram-positive and most Gram-negative contaminating organisms. E.ictaluri can be separated from E.tarda because it is indole-negative and does not produce H2S on triple sugar iron (TSI) agar.  

The organism is '''slow growing''' and '''forms small, translucent, greenish colonies on Edwardsiella isolation media (EIM)''', while inhibiting Gram-positive and most Gram-negative contaminating organisms. ''E.ictaluri'' can be separated from ''E.tarda'' because it is '''indole-negative''' and '''does not produce H2S on triple sugar iron (TSI) agar'''.  

 

==Treatment==

==Treatment==

Potentiated sulphonamide, sulfadimethoxine, methoprim or oxytetracycline have been used to treat ESC, but resistance has been recorded.

'''Potentiated sulphonamide, sulfadimethoxine, methoprim or oxytetracycline''' have been used to treat ESC, but '''resistance''' has been recorded.

==Control==

==Control==

ESC may be controlled through reducing the amount of stress in fish stocks and cessation of feeding when outbreaks occur.  A vaccine called Aquavac ESC is available and administered in water by bath immersion.  

ESC may be controlled through '''reducing the amount of stress in fish stocks and cessation of feeding when outbreaks occur'''.  A '''vaccine''' called '''Aquavac ESC''' is available and administered in water by '''bath immersion'''.  

==References==

==References==