الفهرس | Only 14 pages are availabe for public view |
Abstract Infectious bronchitis disease is a highly contagious and acute illness, caused by infectious bronchitis virus (IBV). Reproductive, renal, and respiratory systems of chicken are all impacted. IBV is an enveloped virus that varies in shape from pleomorphic to spherical, with club-shaped surface projections. Great numbers of IBV strains has been emerged due to the ability of IBV to mutate and recombine genetically that leads to antigenic shift and drift correlated to RNA recombination, mutations, insertions, and deletions. Significant economic devastation is caused in commercial chicken farms due to continuous IBV endemic occurrence. Most antiviral therapies are costly and not effective against viral diseases so, the concern should be focused on the diagnosis, prevention and control of the virus by using plant extracts. In the current study, a total of 150 samples of (trachea, lung and kidney) were collected from freshly dead chickens suffered from severe respiratory signs including : nasal discharge, sneezing, coughing, and gasping. These samples were collected from 30 different farms (5 birds /farm) in Delta region (Dakahlia and Damietta) governorate, Egypt from 2020 to 2022. Specimens of trachea, lung and kidney were collected from each diseased chicken suspected to be infected with IBV. Samples obtained from each farm were pooled as one sample. Finally, 30 working samples were obtained after pooling samples of each farm together. Cultivation of IBV suspected prepared samples in 10- days SPF-ECEs via the allantoic cavity. The samples were isolated for three successive passages. Hyperimmune sera (polyclonal antibodies) were prepared against IBV in white healthy male New zealand-bred rabbits. Serological identification of IBV isolated on allantoic sac of SPF-ECEs using AGPT. Molecular identification of IBV isolates using conventional RT-PCR targeting 5’-UTR gene (134bp).Titration of the allantoic fluid of the third passage of selected isolate (No. 20) was used for the experimental study. In this study, In-ovo detection of the effect of ten percent aqueous extract of Turmeric and Ginger rhizomes on the selected isolate was used separately. Forty SPF-ECEs were used for five groups: G1 (control negative), G2 (control positive), G3A (inoculated by Turmeric then IBV), G3B (inoculated by Ginger then IBV), G4A (inoculated by IBV then Turmeric), G4B (inoculated by IBV then Ginger), G5A (inoculated with a mixture of Turmeric and IBV), G5B (inoculated with a mixture of Ginger and IBV). The results indicated in In-ovo study were evaluated by detecting of embryo changes, RPHA test, conventional RT-PCR. The result obtained in this study Thirty suspected samples were isolated on allantoic sac of 10-days old SPF-ECEs for 3 successive passages. In the first passage, all embryos showed normal size with no lesions. In the second passage, embryos of 18 samples (60%) showed slight curling and dwarfing. In the third passage, embryos of 22 samples (73.33%) showed stunted growth, hemorrhage with clear curling and dwarfing. Serological identification of the allantoic fluid of 30 samples by AGPT using HIS of rabbits showed positive precipitation lines with 12 fluids (40%) from the tested fluids. Further molecular investigation of the same isolates revealed that 9 isolates (30%) of the 30 showed expected band at 143 bp after conventional RT-PCR amplification of 5’ UTR gene fragment. Titration the allantoic fluid of the selected isolate (No. 20) and the calculated titer of the virus was 104.5 ELD50. The In-ovo study of the antiviral effect of Turmeric and Ginger extracts on IBV in the five groups showed that the titer of IBV was the lowest in groups G3A (20.8) which inoculated by Turmeric then IBV and G3B (21) which inoculated by Ginger then IBV which were compared to control positive group and other groups. So, Using of aqueous extract of dried Turmeric and Ginger rhizomes before virus infection can relatively reduce the IBV disease expression as it has strong antiviral effect. |