Aims: Infectious bronchitis virus (IBV) is a highly contagious, acute viral respiratory disease that mostly affects chickens. The poultry sector has suffered enormous losses as a result of IBV. Currently, live attenuated vaccines are routinely used to prevent and control IBV. However, due to the enormous genetic variety, vaccinations are becoming ineffective, with low cross-protection effects among vaccine serotypes. The present study aimed at investigating the possible antiviral effects of curcumin, epigallocatechin gallate (EGCG) and their mixtures against IBV in vivo. Methodology and results: Curcumin, EGCG and their combinations were administered to infected and uninfected chicken groups and viral load titers were determined by real-time PCR. The clinical symptoms of both the negative and positive control groups were also compared. Finally, the trachea tissues of each group were examined histopathologically. According to our findings, the viral titer and the clinical signs dropped significantly during the pretreatment infection procedure. Curcumin, EGCG and their combinations also show significant antiviral activities. Conclusion, significance and impact of study This study clearly shown that natural compounds and their combinations, such as curcumin or/and ECGC can reduce viral pathogenicity in vivo, suggesting that they might have therapeutic implications in the poultry sector.
Infectious bronchitis virus--physiology ; Curcumin ; Catechin

An infectious cDNA clone of H120 vaccine strain of infectious bronchitis virus (IBV) was constructed to demonstrate its potential as a gene transfer vector. Primers were designed according to the published genome sequence of H120 strain, and ten cDNA fragments covering the entire genome of H120 strain was amplified by RT-PCR. All the PCR products were ligated into pMD19-T vector and sequenced, and the ORF5a open reading frame in the pMDTM9 plasmid was replaced by an enhanced green fluorescent protein (EGFP) gene. Recombinant plasmids were digested by the restriction enzyme Bsa I, and all the cDNA fragments were recovered. By using appropriate ligation strategy, the genomic cDNA of H120 strain were reconstituted. Then genome RNA was synthesized in vitro by T7 RNA polymerase and transfected into BHK-21 cells. Recombinant virus expressing the green fluorescent protein was rescued and identified by RT-PCR and sequencing. The characteristics of recombinant virus were evaluated by passage in embryonated chicken eggs. This study showed that the 5a ORF is a good candidate for an insertion site of recombinant genes for the development of IBV infectious cDNA clone as a gene transfer vector.
Animals ; Cell Line ; Chick Embryo ; Cricetinae ; DNA, Complementary ; genetics ; metabolism ; Gene Expression ; Gene Transfer Techniques ; instrumentation ; Genetic Vectors ; genetics ; physiology ; Green Fluorescent Proteins ; genetics ; metabolism ; Infectious bronchitis virus ; genetics ; physiology

The protective efficacy of DNA plasmids encoding avian infectious bronchitis virus (IBV) S1, N, or M protein was investigated in chickens. Chickens were inoculated monovalently (with plasmid pVAX1-16S1, pVAX1-16M, or pVAX1-16N alone) or multivalently (combination of the three different plasmids, pVAX1-16S1/M/N). A prime-boost immunization protocol against IBV was developed. Chickens were immunized with the multivalent DNA vaccine twice and then boosted with an inactivated vaccine once. Antibody titers of the chickens immunized with pVAX1-16S1/M/N were much higher than those of the monovalent groups (p < 0.01). A protective rate up to 90% was observed in the pVAX1-16S1/M/N group. The serum antibody titers in the prime-boost birds were significantly higher than those of the multivalent DNA vaccine group (p < 0.01) but not significantly different compared to the inactivated vaccine group at 49 days of age. Additionally, the prime-boost group also showed the highest level of IBV-specific cellular proliferation compared to the monovalent groups (p < 0.01) but no significant difference was found compared to the multivalent DNA vaccine group, and the prime-boost group completely protected from followed viral challenge.
Aging ; Animals ; Antibodies, Viral/blood ; Cell Proliferation ; Chickens ; Coronavirus Infections/prevention & control/*veterinary/virology ; Immunization, Secondary/veterinary ; Infectious bronchitis virus/*immunology ; Poultry Diseases/*prevention & control/virology ; T-Lymphocyte Subsets/cytology/physiology ; Vaccines, DNA/immunology ; Vaccines, Inactivated/immunology ; Viral Vaccines/*immunology

This study aimed to understand the dynamic distribution of infectious bronchitis virus (IBV) Jin-13 strain in SPF chickens. Ninety-day-old SPF chickens were inoculated with Jin-13, a virulent strain, and dissected at day 1, 4, 7, 10, 14, 21, 28 or 35 post-inoculation (dpi). Samples of heart, liver, spleen, lung, trachea, kidney and duodenum were collected and the N gene was detected by Sybr Green I real-time quantitative RT-PCR assays. The established method had a good linear correlation from 7.77 x 10(8) to 10(0) copies/microL. SPF chickens developed typical clinical signs of IBV at the 4th dpi, and the IBV viral concentration of tissues and organs gradually increased with a peak of up to 7.13 x 10(4) copies/microL. The viral concentration of most organs decreased by the 10th dpi, but those of the kidney, trachea and lung remained positive for IBV at 28 dpi and the heart was still positive for IBV at > 35 dpi. The results of this study, showed that the Jin-13 strain can cause prolonged virus excertion in chickens with severe renal damage.
Animals ; Chickens ; Coronavirus Infections ; veterinary ; virology ; Infectious bronchitis virus ; isolation & purification ; pathogenicity ; physiology ; Lung ; virology ; Poultry Diseases ; virology ; Reverse Transcriptase Polymerase Chain Reaction ; Specific Pathogen-Free Organisms ; Trachea ; virology ; Virulence