MOLECULAR DETECTION OF MEGALOCYTIVIRUS GENOTYPE: INFECTIOUS SPLEEN AND KIDNEY NECROSIS VIRUS IN MALAYSIAN OVIPAROUS AQUARIUM FISH

The Malaysian ornamental fish industry’s recent production is recorded at RM350 million per annum. An Infectious Spleen and Kidney Necrosis Virus (ISKNV), one of the Megalocytivirus strains has been related to significant systemic infections that has ravaged ornamental fish stocks and had a severe financial impact on businesses in the sector. It is vital to identify Megalocytivirus host species among Malaysian oviparous ornamental fish as the virus can cripple the ornamental fish trade which is a major contributor to the country’s export trade. The purpose of this research is to determine the prevalence of Megalocytivirus, ISKNV strain in oviparous aquarium fish, Betta splendens, Danio rerio, Trichogaster lalius, Hyphessobrycon anisitsi and Puntigrus tetrazona in Malaysia. The DNA of the Megalocytivirus in the samples was detected using the nested polymerase chain reaction (PCR) method. Out of 239 samples collected in January 2019 and January 2020, six pooled samples (n=30) tested positive for ISKNV infections in D. rerio and T. lalius. Positive P. tetrazona samples in this study showed a distended abdomen as the only observable clinical sign whereas all other samples were asymptomatic. All the positive samples were similar to each other. In terms of the nucleotide identity of the ISKNV, which stood at between 98% and 100%. In conclusion, the positive samples can be categorised into Megalocytivirus genotype I.

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