Genotypic And Serotypic Characterization Of Infectious Bronchitis Virus Of Chickens
| dc.contributor.advisor | Raj, G. Dhinakaran | |
| dc.contributor.advisor | Thiagarajan, V | |
| dc.contributor.advisor | Ramadass, P | |
| dc.contributor.advisor | Manohar, B. Murali | |
| dc.contributor.author | Raja, A | |
| dc.contributor.author | TANUVAS | |
| dc.date.accessioned | 2016-05-27T14:08:27Z | |
| dc.date.available | 2016-05-27T14:08:27Z | |
| dc.date.issued | 2006 | |
| dc.description.abstract | A total of 161 samples were screened for the presence of IBV genome by ‘N’ gene nested RT-PCR and twenty four were positive. All the positive samples on further passages revealed IBV specific lesions such as dwarfing of embryos with curled toes in ECE. A part of the S1 gene (220 bp) could be amplified by RT-PCR in 22 out of 24 'N' gene RT-PCR positive samples. For eight field isolates, the 5’ end (600 bp) and 3’ end (464 bp) of S1 gene were amplified and sequenced. In addition, the 5' end of two isolates, Ind/KA/151/05 and Ind/Hy/152/05 were sequenced using the 600 bp product while the 3' end of two other isolates, Ind/KA/135/04 and Ind/Hy/154/05 were sequenced using the 500 bp (outer) or 400 bp (nested) product. On sequence analysis all the twelve isolates were found to belong to Mass 41 genotype. On comparison with the vaccine strain, H120, sequence homologies of the field isolates ranged from 87.9 to 95.9 per cent for the 5’ end of ‘S1’ gene and 90.7 to 98.9 per cent for the 3’ end of ‘S1’ gene. The analysis of HVR I, II and III sequences revealed that the field isolates were less homologous with vaccine strain, nucletide homologies ranging from 70 to 100 per cent. The d s / d ns ratio for 80 per cent of the sequenced field isolates was less than 1.0. The serotype of five isolates (Ind/TN/92/03, Ind/TN/97/03, Ind/114/03, Ind/KA/135/04 and Ind/KA/136/04) was determined by cross neutralization test using homologous and heterologous sera. All were found to belong to Mass 41 serotype. In vivo challenge (protectotypic) experiments, demonstrated the ability of the most commonly used vaccine H120, to induce protection against five field isolatestested. Birds vaccinated with H120 and challenged with the field isolate, Ind/TN/92/03 showed the lowest protection score. The pathotypic trial revealed that the isolate, Ind/TN/92/03 also had the highest lesion score (25.0) and hence was considered as the virulent Mass 41 virus. A live attenuated vaccine was prepared by passaging the isolate Ind/TN/92/03, twenty five times in ECE. The live attenuated vaccine afforded protection to homologous challenge in 3 week old chickens equal to that of the commercial H120 vaccine. The inactivated vaccine was also produced from the same isolate. The inactivation was done by formalin and the inactivated virus was mixed with oil as adjuvant. The inactivated also produced good ELISA titre in live attenuated vaccine primed but not in unprimed birds | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/66385 | |
| dc.language.iso | en | en_US |
| dc.publisher | Tamil Nadu Veterinary and Animal Sciences University | en_US |
| dc.sub | Animal Biotechnology | |
| dc.subject | IBV | en_US |
| dc.subject | genotype | en_US |
| dc.subject | serotype | en_US |
| dc.subject | protectotype | en_US |
| dc.subject | pathotype | en_US |
| dc.subject | live attenuated | en_US |
| dc.subject | killed vaccine | en_US |
| dc.these.type | Ph.D | |
| dc.title | Genotypic And Serotypic Characterization Of Infectious Bronchitis Virus Of Chickens | en_US |
| dc.type | Thesis | en_US |