Determination of a novel parvovirus pathogen associated with massive mortality in adult tilapia.

摘要: Tilapia is one of the most important economic and fastest-growing species in aquaculture worldwide. In 2015, an epidemic associated with severe mortality occurred adult tilapia Hubei, China. The causative pathogen was identified as parvovirus (TiPV) by virus isolation, electron microscopy, experimental challenge, situ hybridization (ISH), indirect immunofluorescence (IFA), viral gene sequencing. Electron microscopy revealed large numbers particles organs diseased fish, including kidney, spleen, liver, heart, brain, gill, intestine, etc. virions were spherical shape, non-enveloped approximately 30nm diameter. TiPV isolated propagated brain cells (TiB) induced a typical cytopathic effect (CPE) after 3 days post-infection (dpi). This used to experimentally infect clinical disease symptoms similar those observed naturally replicated. Additionally, results ISH IFA showed positive signals kidney spleen tissues from TiPV-infected fish. To identify TiPV-specific sequences, near complete genome obtained determined be 4269 bp size. Phylogenetic analysis NS1 sequence that novel parvovirus, forms separate branch proposed genus Chapparvovirus Parvoviridae. Results presented here confirm can cause massive tilapia. provides basis for further studies define epidemiology, pathology, diagnosis, prevention treatment this emerging disease.