Clinical and Molecular Study of Koi Herpesvirus (KHV) Emerged in Oreochromis niloticus from Indonesia

Abstract

Background and Objective: Koi Herpesvirus (KHV) can infect some species of freshwater fish, other than Cyprinidae. As well this possibility, in which tilapia may be infected with KHV, this study aimed to detect KHV from tilapia in Gresik, East Java, Indonesia using clinical and molecular study. Methodology: The study was carried out by examining clinical symptoms of tilapia and PCR examination followed by a sequence analysis and then aligned with BioEdit and the construction of phylogenetic trees was determined using the Neighbors-Joining. Results: The clinical symptoms observed from tilapia were discoloration on the skin and white patches on the gills. A sequence analysis using TK gene and PCR duplex analysis (marker I and marker II) indicated that the KHV genotype of the tilapia was identical to the A1 variants and displayed allele I++ II+ allele of the Asian genotype. Conclusion: The genetic variations of KHV observed from tilapia clearly indicated that the KHV genotype infecting tilapia is an Asian genotype. However, although tilapia was infected with KHV, no specific apparent of clinical symptoms and no mortality was seen in tilapia. Key