A virus was isolated from cultured sick giant salmander (Andrias davidianus ) in a farm, Shanxi Province, China. Skin ulceration and necrosis of the distal limbs are main clinical symptoms. Virus propagated and caused CPE at 10 degrees C to 30 degrees C in BF-2, CO, CHSE, FHM cells. The optimum condition of replication was in BF-2 cells at 25 degrees C. The virus was proved to be senstive to chloroform, heat, pH3 and pH10 treatment. Viral replication was inhibited by 5-Fluoro-2-deoxyuridine (FUDR). These results indicated that the virus possessed an envelope and DNA as the genome. Electron-microscopic observation of thin-section showed numerous hexagonal viral particles measuring 130 nm to 150 nm in diameter orderly arranged in a lattice form in cytoplasm of BF-2 cells. The particles showed typical iridovirus morphology. A 413 bp fragment was amplified from the viral main capsid protein gene by PCR. The fragments was sequenced and analysed. The results showed the isolate shared more than 96% nucleotide identity with some Ranaviruses. We suggested that this virus was named as Andrias davidianus iridovirus (ADIV) tentatively.
Animals ; Base Sequence ; Iridovirus ; genetics ; isolation & purification ; Molecular Sequence Data ; Urodela ; virology

During the summer of 2009, mass mortality was observed in cage-cultured Rock Bream (Oplegnathus fasciatus; Temminck and Schlegel) in the Liaoning Province. Histopathogic studies of the affected fish showed enlarged basophilic cells in the kidney and spleen. These necrotic cells were stained purple using haematoxylin and eosin (HE). GF cell cultures showed advanced cytopathic effects after infection with virus supernatants from diseased fish homogenate. Transmission electron microscopy revealed hexagonal outlines virions in the cytoplasm of the spleen, kidney, liver, intestine cells. The viral particles consisted of a central nucleocapsid (100-110 nm) and envelope, and were 150-180 nm in diameter. These results suggested that the virus belonged to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570-bp fragments were amplified from the viral DNA in spleen, kidney, gill, intestine, heart and brain of diseased fish with the primers derived from red sea bream Iridovirus (RSIV). In addition, a specific fragment of 1 400 bp of the major capsid protein (MCP) gene of the Iridovirus was amplified by PCR. A phylogenetic tree was constructed to compare the corresponding genetic sequences in Megalocytivirus. The tree demonstrated that RSIV-LN09 virus existed in the same branch as the RSIV-U1 et al. Our present results indicated that RSIV was the causative agent.
Animals ; DNA, Viral ; genetics ; Iridovirus ; classification ; genetics ; isolation & purification ; physiology ; Microscopy, Electron ; Perciformes ; virology ; Phylogeny ; Polymerase Chain Reaction