Title : Prevalence and molecular characterization of novel DHPV in Korean shrimp farms
Abstract:
Decapod hepandensovirus 1 (Decapod hepanhamaparvovirus 1, DHPV) is a viral pathogen causing growth retardation and decreased feed conversion efficiency in penaeid shrimp. The virus exhibits high genetic variation between different hosts and geographical locations. Primarily, it has been reported in cultured Penaeus monodon, P. chinensis, and P. merguiensis. Recently, a new type of DHPV has been identified in P. vannamei cultured in Korea and Taiwan. This study reports the result of DHPV screening test in shrimp farms and the genome of this new type of DHPV. This study is the first to report the complete genomic sequence of DHPV identified in P. vannamei. To screen for DHPV, 113 specimens of cultured shrimp were collected from 14 shrimp farms in Korea. Among the collected shrimp samples, DHPV was detected in 98 samples (86.7%) from all 14 shrimp farms. The full genome was successfully amplified using a combination of conventional Sanger sequencing and next- generation sequencing approach. The newly identified DHPV in P. vannamei contained a linear, single- stranded DNA genome of 6,173 bp comprising three major open reading frames, similar to other types of DHPVs that infect several shrimp species other than P. vannamei. However, detailed comparative genome and phylogenetic analysis revealed that the virus did not cluster with the pre-existing genotypes, suggesting the emergence of a novel genotype of DHPV in cultured shrimps. The high prevalence of DHPV in the sampled shrimp farms highlights the need for efficient management strategies to control the spread of the virus in aquaculture farms. The emergence of a new genotype of DHPV in P. vannamei poses a significant threat to the shrimp aquaculture industry, as it may exhibit different virulence and pathogenicity characteristics. The complete genomic sequence of the newly identified DHPV provides a basis for further research on the virus's biology, pathogenicity, and epidemiology. In conclusion, this study presents significant insights into the genetic diversity of DHPV in P. vannamei and emphasizes the need for continued monitoring and management strategies to control the spread of the virus in shrimp aquaculture.
