Humans ; Persistent Infection ; Orthoreovirus/genetics* ; Reoviridae Infections/veterinary*

In this study, pEGFP-N1 was chosen as the reporter plasmid and transferred into Ctenopharyngodon idellus kidney (CIK) cells by electroporation, and the optimal electroporation conditions were determined by testing the transfection efficiency with different voltages, pulse times, plasmid amounts, and numbers of shocks. The results showed that the maximum electroporation efficiency was achieved under the following conditions in a 0.2 cm electroporation cuvette containing CIK cells (1.5 x 10(7)/mL, 200 microl): electric voltage 200 V, pulse time 45 ms, plasmid 30 microg, and one electric shock. The total genomic RNA of grass carp reovirus (GCRV) was extracted in this experiment and reversely transcribed into cDNA, which was used to amplify the gene segment of GCRV non-structural protein NS26 using designed specific primers. The PCR product was recombined into pEGFP-N1 vector. The fusion protein EGFP-NS26 was successfully and efficiently expressed in the CIK cells by electroporation, which was confirmed by both fluorescent imaging and Western blot analysis. This experiment laid a foundation for further functional studies of the non-structural protein NS26 of GCRV.
Animals ; Cell Line ; Cyprinidae ; Electroporation ; Fish Diseases ; virology ; Gene Expression ; Kidney ; virology ; Reoviridae ; genetics ; physiology ; Reoviridae Infections ; veterinary ; virology ; Viral Nonstructural Proteins ; genetics ; metabolism

A strain of grass carp reovirus was isolated from sick grass carp with symptoms of haemorrhage in Guangdong province in 2009. The strain was tentatively named as GCRV-GD108 because it was isolated from grass carp and possessed 11 segments of dsRNA. Complete genome sequence analysis showed that significant differences existed between GCRV-GD108 and GCRV, as well as other known species of aquareovirus. In this study, molecular characteristics of diseased grass carp collected from different farms in Guangdong, Fujian and Hunan provinces were assayed. Based on the sequences of the 11 segments of GCRV-GD108, PCR primers corresponding to each of the segments were designed and synthesized. Total RNA of the diseased fish was extracted and used as templates of RT-PCR reaction. Specific amplification bands were obtained from all of the samples whereas no band was produced from GCRV standard strain. While using the primers specific to GCRV produced specific band in GCRV standard strain rather than in these collected samples. Sequencing of the amplification products showed that these samples displayed high similarities with each other (95.2%-99.4%), and they also shared high sequence similarities with that of GCRV-GD108 (95.0%-99.8%), suggesting that these samples shared similar molecular characteristics with those of GCRV-GD108, and were quite different from GCRV as well as the known species of genus aquareovirus. The results indicated that there are different molecular types of reovirus existed in the pond-cultured grass carp in China, and GCRV-GD108 is a representative strain in southern China, therefore great attention should be paid in order to control the disease efficiently, especially in vaccine preparation. Two pairs of primers were chosen to establish a duplex PCR assay method by combining each pair of the primers specific to GCRV-GD108 with the GCRV primer pair respectively. The duplex PCR assay method will enable the identification of GCRV-GD108 or GCRV by only a single PCR reaction.
Animals ; Carps ; virology ; China ; Fish Diseases ; diagnosis ; virology ; Molecular Sequence Data ; Polymerase Chain Reaction ; methods ; Reoviridae ; genetics ; isolation & purification ; Reoviridae Infections ; veterinary ; virology

By using cell culture and virus infection methods, a new reovirus had been isolated from channel catfish (Ictalurus punctatus) suffered with severe hemorrhage and had been identified as channel catfish reovirus (CCRV) after artificial infection in fish, electron microscopy observation, physical-chemical tests, genomic SDS-PAGE analysis and sequencing. In artificial infection test, the typical symptoms of channel catfish hemorrhage as naturally occurred could be reproduced. The isolated virus could cause typical cytopathic effect in CCO and CCK cell lines. Electron microscopy observation of ultra-thin section samples of CCRV infected CCO and CCK cells revealed that the virus replicated in cytoplasm, arrayed in crystalline, and had a non-enveloped double capsid with a diameter of 60-70 nm. Frozen-thawed, 56 degrees C 1 h, chloroform and ether had no significant effects on CCRV titer, 65 degrees C 1 h could significantly inactivated the viral infectivity. The CCRV genome SDS-PAGE analysis and nuclease sensitivity test showed that the virus genome was the same as that of viruses in Aquareovirudae and consisted of 11 segments of dsRNA assigned into three classes L1, L2, L3; M1, M2, M3 and S1, S2, S3, S4, S5 with a range of size from 0.9 to 4.4 kb. The Cloning and sequencing of the CCRV S4 segment indicated the nucleic acid number of CCRV S4 was 909 bp in length, which was exactly the same as that of GCRV S4 (AF403396) and GSRV S4 (AF403407) segments. The BLAST of CCRV S4 sequence in NCBI GenBank showed that it had a 99% and 90% similarity in sequence to the GCRV S4 and GSRV S4 segments, respectively.
Animals ; Base Sequence ; Catfishes ; Cell Line ; Fish Diseases ; virology ; Molecular Sequence Data ; Reoviridae ; classification ; genetics ; isolation & purification ; ultrastructure ; Reoviridae Infections ; veterinary ; virology

The virus strains were isolated from the liver and spleen of the dead young ducks characterized with symptoms of hemorrhagic-necrotic hepatitis. These isolates could cause the death of muscovy duck-embryo and chick-embryo. 1-day-old birds infected with these isolates had the same character with clinically dead birds and the virus could be isolated from artificially infected birds. These isolates could proliferate in MDEF and result in CPE. The virus could proliferate in the cytoplasm in order of crystals and arranged in the latlic-like. The viron was shown spherical, icosahedron, cubic symmetry, no-envelope, with double-layered capsid, about 70 nm in diameter by electron microscopy. The genome segments of the virus were consisted of L1-3, M1-3 and S1-4, which were similar to that of avian reovirus (ARV). Compared to 68.2%, 69.3% - 70.1%, respectively. The system evolution analysis showed that S3 gene coding sigmaB protein was placed in different branch of MDRV and ARV, indicating that S3 gene of the virus was different from ARV and MDRV. The main clinical symptoms and lesions of ducklings caused by the virus were different from the diseases caused by MDRV and ARV. It was concluded that the virus was a Novel duck reovirus belonging to Orthoreovirus genus of the Reoviridae family.
Animals ; Animals, Wild ; virology ; Bird Diseases ; pathology ; virology ; Chick Embryo ; China ; Ducks ; Molecular Sequence Data ; Orthoreovirus, Avian ; classification ; genetics ; isolation & purification ; Phylogeny ; Reoviridae Infections ; pathology ; veterinary ; virology ; Viral Proteins ; genetics

Muscovy ducks reovirus (DRV) is an important pathogen with a high mortality rate in Muscovy ducks, the researches in the test and the immunity were useful for the prevention and control of DRV infection. In this study, the S3 genes of the three Fujian DRVs were cloned by RT-PCR and sequencing technology. It was found that DRV-YH and YJL were close to avian reovirus (ARV) in the genetic distance, with high identities ranged from 94. 6% to 98. 9%, however, the identities of DRV-YB strain and reference ARV strains in the S3 gene were only 60.6% - 61.7%. The expression vector pET-30a-S3 harboring DRV YB strain S3 gene was constructed and transformed into E. coli BL21, and then the fusion sigmaB protein expression was induced with IPTG. The SDS-PAGE of the expressed products indicated that the fusion protein of approximately 42ku in molecular weight was expressed highly in inclusion body, and made up 67. 7% of the total proteins. The most efficient concentration of IPTG and inducing time were 0. 1 mM and 5h respectively, while the best temperature for expression was 37 degrees C. After purification with the Ni2+ affinity chromatography, the fusion sigmaB protein was 93% of the total proteins, and the purified protein amounted to 0. 86g/L. The Western blot analysis showed that the fusion aB protein was recognized specifically by the antiserum against DRV, confirming that the recombinant fusion protein had good immunoreactivity.
Amino Acid Sequence ; Animals ; Capsid Proteins ; chemistry ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Molecular Sequence Data ; Orthoreovirus, Avian ; chemistry ; classification ; genetics ; isolation & purification ; Phylogeny ; Poultry Diseases ; virology ; RNA-Binding Proteins ; chemistry ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Reoviridae Infections ; veterinary ; virology ; Sequence Analysis ; Sequence Homology, Amino Acid