Experimental Infection with Koi Ranavirus (KIRV) of Common Carp (Cyprinus carpio L.) and Rohu (Labeo rohita H.)

The aim of this study was to determine the pathogenicity of koi ranavirus (KIRV) in common carp (Cyprinus carpio L) and rohu (Labeo rohita H). In the present study, common carp and rohu fingerlings were experimentally infected with KIRV by intraperitoneal injection with 50 µl of the virus preparation having an infectious dose of 106.9 TCID50/ml. After injection, tissues such as spleen and kidney of both challenged fishes with the virus were collected at 3, 7, 14, 21 and 28 dpi for investigation by polymerase chain reaction (PCR), cell culture assay and histopathological technique. KIRV was detected in pooled samples of kidney and spleen collected from both challenged fishes after 3 dpi by PCR, while no positive results were obtained from all other time points. In cell culture assay no cytopathic effect was observed in the EPC (Epithelioma papulosum cyprini) cell line at all time points of both fish species for virus reisolation. The results of the histopathological analysis showed necrosis and hypertrophy in kidney tissue of common carp and necrosis and detachment of glomeruli from the epithelium of tubules in kidney tissue of rohu at 3 and 7 dpi, while no typical pathological changes were observed in spleen tissue of common carp at all time points and melanomacrophage cells were observed in spleen tissue of rohu at 3 dpi. On the whole, results reveal that there is no clear clinical pathology observed in common carp and rohu fingerlings following experimental infection with KIRV.