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ABSTRACT: To investigate molecular epidemiology of DuCV in Cherry Valley ducks in China, the complete genomes of six DuCV strains, which were detected from Cherry Valley ducks in China between 2007 and 2008, were sequenced. Sequence and phylogenetic analysis were carried out to compare these six strains with another 27 DuCV strains from Mulard duck, Muscovy duck, Pekin ducks and Mule duck. The analysis showed that the six DuCV strains exhibited typical genetic features of the family of DuCV, such as a stem-loop structure, three major open reading frames (Rep, Cap and ORF3), four intergenic repeats and the conserved motifs for rolling circle replication and for the dNTP binding domain located in the Rep protein. Phylogenetic analysis of the nucleotide sequences of the complete genome and Cap gene of these strains together with those that have been previously published demonstrated two distinct DuCV genotypes. The DuCV strains with complete genomes containing 1988 and 1989 nucleotides clustered in genotype A, whereas the strains with complete genomes containing 1991, 1992, 1995 and 1996 nucleotides lay in genotype B. The six DuCV strains from Cherry Valley ducks were divided into the two groups. The results of the study provides some insight into the variation of DuCVs in Cherry Valley ducks.
Virologica Sinica 06/2012; 27(3):154-64.
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ABSTRACT: Infection with duck circovirus (DuCV) is associated with growth retardation and developmental problems in farmed ducks. To detect DuCV-specific antibody in duck serum, an indirect enzyme-linked immunosorbent assay (iELISA) method was developed using the recombinant capsid protein antigen prepared by cloning the cap (Cap) gene of DuCV FJ0601 strain into pET-32a (+) vector and expressed in Escherichia coli. Using the optimized iELISA method, DuCV-specific antibodies were detected in 157 (12.96%) of 1211 samples obtained from 17 (89.47%) of 19 meat duck flocks aged from 25 to 40 days and in 89 (22.08%) of 403 samples obtained from 9 (75%) of 12 breeder flocks aged from 14 to 61 weeks. These results indicated that the iELISA method is useful for serological diagnosis of DuCV infection and epidemiological investigation.
Veterinary Microbiology 09/2010; 145(1-2):41-6. · 3.33 Impact Factor
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ABSTRACT: Avian hepatitis E virus (HEV) has been identified in chickens; however, only 4 complete or near-complete genomic sequences have been reported. We found that the near-complete genomic sequence of avian HEV in chickens from China shared the highest identity (98.3%) with avian HEV from Europe and belonged to avian HEV genotype 3.
Emerging Infectious Diseases 09/2010; 16(9):1469-72. · 6.79 Impact Factor
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ABSTRACT: The clinical symptoms of infectious coryza are multiple and include nasal discharge, facial swelling, lacrimation, and anorexia. In general, the disease is not fatal to chicken; so, in experiments where animals are infected with Avibacterium paragallinarum, there have been debates about conducting the challenge model and evaluating the clinical signs. In this experiment, 150 chickens, aged 30 days, were randomly divided into different groups. Some groups were infected with the 'in-contact' challenge model and others with the artificial intrasinus-injection-route model. The bacterial isolates used were three field isolates of different serogroups of A. paragallinarum, including Hpg-8 (Page serovar A), CCM6075 (Page serovar B) and Hpg-668 (Page serovar C). During this study, a scoring system was used to record the clinical signs of the infected birds and evaluate the pathogenic diversity of the two models. The final results indicated that the 'in-contact' challenge model of the three isolates showed a more reliable representation of the natural infection under field conditions than the artificial intrasinus-injection-route model. Thus, on carrying out animal experiments, the effect of 'in-contact' challenge model is more accurate than the artificial intrasinus-injection-route model.
Veterinary Microbiology 09/2009; 141(1-2):68-72. · 3.33 Impact Factor
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ABSTRACT: The duck circovirus (DuCV) infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy
ducks with infectious serositis were collected from 12 duck farms in Fujian Province. Based on the published sequences of
DuCV, two primers were designed for the detection of DuCV and four pairs of primers were designed to amplify four overlapping
fragments that cover the complete genome of DuCV. The specific PCR products were amplified from positive samples. The fragments
were then cloned into pMD18-T vector and sequenced, and the full length genomic sequence of the FJ0601 isolate of DuCV was
obtained. PCR analysis showed that the proportion of ducks which were positive for circovirus was 79% and 10 out of the 12
farms were positive. Sequence analysis showed that the complete genome of DuCV-FJ0601 was 1988 bp and possessed features common
to the family Circoviridae which included a stem-loop structure and the Rep protein motifs. Homology analysis showed that
FJ0601 isolate of DuCV had 97.3%∼97.5% nucleotide sequence identity to all the four Taiwan isolates (TC1/2002, TC2/2002, TC3/2002,
TC4/2002), 82.9% identity to the America (33753-52) isolate and 82.3% identity to the Germany isolate. Phylogenetic analysis
with Clustal W, however, showed that FJ0601 isolate of DuCV was on a common branch with Taiwan isolates, and Germany and America
isolates belonged to the other branch.
Virologica Sinica 07/2008; 23(4):265-271.
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ABSTRACT: The genomic DNA extracted from chicken embryo fibroblasts (CEF) of SPF chickens from three chicken farms was used as template to amplify the ALV proviral DNA by PCR with four pairs of primers, high positive detection rates of gag - gene (29/46), pol - gene (27/46), env - gene (24/46) and LTR fragment (31/46) were achieved. Eight continuous and overlapping fragments were amplified from one DNA sample with 8 pairs of primers according to published sequences, then cloned into the TA vector and se quenced. The complete sequence of the whole genome of ALV strain SD0501 was established and analyzed with DNAstar software. Comparisons of SD0501 sequence with that of other representative endogenous avian virus strains demonstrated that the genomes of ALV were relatively conservative, the nucleotide identity of all the strains was over 99.1%, and env - gene was over 98.5%. However, a low identity was demonstrated among the representative strains of different subgroups, especially, the env - gene showed obvious difference, the corresponding identity was as low as 56.3% - 91.5%.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 02/2008; 24(1):53-8.
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ABSTRACT: Newcastle disease is an acute and highly contagious disease caused by Newcastle disease virus (NDV), one of which does great harms to the poultry industry. The most basic measure of controlling New Castle disease is to alid vaccine, now we usually use La Sota live vaccine and inactivated NDV vaccine, but these two vaccines both have more or less limitation. It can produce higher mucosal immunity titers by taking vaccine orally, meanwhile it can induce humoral and cell-mediated immune response and mucosal immunity strongly. Therefore, it becomes the focus of the research, which prepare new pattern vaccines taking orally. NDV chitosan microsphere vaccine was prepared using chitosan as capsule wall material, NDV as core material, glutaraldehyde as cross-linking material, and its even particle diameter was 5.83um, and its surface was smooth and glossy, no obviously pore space, yellow brown pykno-ball, and its safety and potency were evaluated. The SPF chickens were immunized with NDV chitosan microsphere vaccine, La Sota live vaccine and inactivated NDV vaccine respectively. To evaluate vaccine's immune efficacy, using MTT to measure lymphocytes proliferation in vitro, using HI to measure serum special IgG and using ELISA tests to detect mucosal sIgA titers. The results show that NDV chitosan microsphere vaccine was safe, could induce humoral and cell-mediated immune response and mucosal immunity strongly. The results of the potency tests conformed that the vaccine could produce good protective effect.
ACTA MICROBIOLOGICA SINICA 09/2007; 47(4):692-6.
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ABSTRACT: A recombinant baculovirus expressing reticuloendotheliosis virus env gene was constructed with Bac-to-Bac Baculovirus Expression Systems. After transfecting the recombinant virus into Sf9 cells for 3 days, REV env can be detected by indirect immunofluorescence antibody assay (IFA) and Western blot with specific monoclonal antibodies of REV. The oil-water emulsion vaccine was then produced using this infected Sf9 cells lycates and inoculated SPF chickens to validate the immunogenicity for REV. The results show that special anti-REV antibody can maintain more than 45 days and resist the infection of REV viruses. This is the first success to induce anti-REV antibody in chickens by none-live viruses.
ACTA MICROBIOLOGICA SINICA 09/2005; 45(4):593-7.
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ABSTRACT: PCV-2 (Porcine circovirus type-2, PCV-2) and PRRSV (Porcine reproductive and respiratory syndrome virus, PRRSV) were detected by PCR from 253 porcine pleuropneumonia samples and 125 clinically healthy lung samples were collected from different districts of Shandong province. The results showed that 171 samples for PCV-2 and 101 samples for PRRSV were positive. The positive ratio were 67.5% and 40%, respectively. The co-infection number of PCV-2 and PRRSV was 68 in 253 samples, the positive ratio was 26.8%. While in the clinically healthy samples, only 21 samples for PCV-2 and 12 samples for PRRSV were detected positive, the positive ratio were 16.8% and 9.6%, respectively, no co-infection samples were found. Statistical result showed significant difference between positive ratio for PCV-2 and PRRSV in porcine pleuropneumonia samples and that of in clinically healthy samples. The above results demonstrated that there maybe some relationship between the infection of porcine pleuropneumonia and PCV-2 and PRRSV in pigs.
ACTA MICROBIOLOGICA SINICA 07/2005; 45(3):397-400.
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ABSTRACT: The bi-directional promoter between pp38 gene and 1.8kb mRNA transcripts of Marek's disease viruses (MDV) was divided into two single-direction promoters from the replication of MDV genomic DNA. The pp38 gene was cloned into pUC18 vector for plasmid pUC-pp38. Then the complete bi-directional promoter was cloned into pUC-pp38 in two directions to form plasmids pPro(f)pp38 and pPro(r)pp38, and the divided two single directional promoters were cloned in pUC-pp38 for plasmids pdPro(f)pp38 and pdPro(r)pp38. 24 to 48 hours after transfection to chicken embryo fibroblast (CEF) cells, the expression of pp38 could be detected in above 4 samples with Indirect Immuno-fluorescent Assay (IFA). In order to analysis the activity of the promoter quantificationally, CAT was used as the report gene. The complete or divided promoters were cloned into pCAT-Basic vector for plasmids pPro(f)CAT, pPro(r)CAT, pdPro(f)CAT and pdPro(r)CAT. The activity of CAT was measured from the lysed CEF cells, when they were transfected for 48 hours by the above four plasmids, respectively. The results showed the activity of the divided promoters reduce on both directions, especially for the direction of 1.8kb mRNA transcript, nearly down to 1/41.
ACTA MICROBIOLOGICA SINICA 07/2005; 45(3):363-7.
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ABSTRACT: By using PCR, 3 fragments of provirus cDNA of avian leukosis virus (ALV-J) strain NXO101 were amplified from the genomic DNA of ALV-J infected cells,and then combined in the right direction and sequences into recombinant plasmid pALV-J-NX, containing the whole genome of NX0101. After transfection of chicken embryo fibroblast (CEF) cells with plasmid pALV-J-NX DNA, the rescued virus was identified in CEF by indirect fluorescence antibody test with ALV-J specific monoclonal antibody JE9. The rescued virus could replicate in CEF at a titer of 10(5.6)/mL. The chicken experiment demonstrated that the rescued virus was still able to induce tumors in commercial meat-type broilers.
ACTA MICROBIOLOGICA SINICA 07/2005; 45(3):437-40.
