Pathogenesis of edwardsiella ictaluri in African labyrinth catfish [clarius lazera]

ABSTRACT

African labyrinth catfish [Clarias lazera] were experimentally infected by intramuscular injection with 3.8 x 10[7] viable Edwardsiella ictaluri cells. Sampling infected fish at different time [24, 48, 96h, 1 and 2 weeks] allowed us to follow the progress of infection. Infected fish clearly demonstrated acute septicemia by the time it became chronic in nature with a low mortality rate [8%]. There were significant reducations in erythrocyte, leucocyte numbers and hemoglobin concentration. The spleen and kidney were necrotic with an increase in inflammatory cells. Severe cellular vacuolation and degeneration with marked endocarditis were observed in the heart. Typical chronic infectious granulomata developed 2 weeks post-infection at the injection site and associated with the organs