Immunological Diagnosis of Naturally Eus Infected Channa Gachua

An immunological approach has been adopted to diagnose the causative agent/s of Epizootic Ulcerative Syndrome (EUS). It has been clearly established by the observation of syndrome under natural condition that it develops at three different consecutive stages i.e. the initial stage (red spots occur on whole body) followed by an advanced stage (a red circular ring, distinguished by the circular hemorrhagic ring), which ultimately terminated to an ulcer. To assess the involvement of various claimed pathogens in EUS, two serological tests, DIBA (Dot-Blot ELISA) and IEM (Immunoelectron Microscopy), have been conducted at the three different stages of syndrome. It is clearly revealed by both the tests that only the virus (SHRV-19E) has been found at initial stage. At the next stage involvement of SHRV-19E as well as a fungus (Aphanomyces invadens) have been reported while at last ulcerative stage; only the involvement of bacterium (Aeromonas hydrophila) and fungus (Aphanomyces invadens) have been reported. To test the virulency of aforesaid pathogens for the infected Channa gachua a lymphocytes transformation test (LTT) and serum profiling have been conducted. The maximum transformation has been reported against the SHRV-19E followed by Aphanomyces invadens while least was against Aeromonas hydrophila. In serum profiling also, nearly similar results have been observed.