51 巻 (2016) Special-issue 号 p. S66-S74
In order to determine the aetiology of cultivable freshwater carp mortalities of Northeast Indian states, we analysed infected fish samples by virus isolation using cell cultures and virus detection by PCR. The fishes collected from Manipur had typical ulcerative dermal lesions resembling epizootic ulcerative syndrome (EUS). Samples from Northeast India were analysed by PCR and ranaviral major capsid protein specific DNA was detected in one of the 66 tissue samples collected from 12 infected fish (kidney of Puntius sarana) of Assam and nine out of 15 infected Osteobrama belangeri samples of Manipur. Sequence analysis of a 289 bp fragment of one of the amplified DNA from infected fishes of Northeast India showed 98.9% homology with the major capsid protein gene of koi ranavirus (KJ939444), which we earlier isolated from infected koi that were undergoing mortalities and characterised to belong to Ranavirus genus of the family Iridoviridae. Our results have revealed the presence of ranavirus in freshwater fishes suffering from mortalities in Northeast India. As ranaviruses are known for their genomic adaptive changes facilitating host shift between fish, amphibian and reptilian hosts, there is a need to pay attention to the spread of emerging ranavirus infection in fishes.