Ahmed Z, Naeem K, Hameed A
National Reference Laboratory for Poultry Diseases, Animal Sciences Institute, National Agricultural Research Center, Park Road, Islamabad, Pakistan.
Poult Sci. 2007 Jul;86(7):1329-35. doi: 10.1093/ps/86.7.1329.
This study was conducted to investigate the incidence of infectious bronchitis virus (IBV) in commercial broiler and layer flocks in Pakistan. Serum samples from 16 layers and 9 broiler flocks were screened against M-41, D-274, D-1466, and 4-91 strain antigens using hemagglutination inhibition assay. Overall, 88% of the flocks were seropositive for M-41 antibodies, whereas 40, 52, and 8% of the flocks were positive for D-274, D-1466, and 4-91 IBV strains, respectively. The M-41 antigen was also detected in lungs and tracheal tissues of the clinically positive infectious bronchitis cases. Phospholipase C treatment of the lung and tracheal tissue homogenates from IBV-positive chickens increased the detection limit for M-41 strain from 1.3% positive samples in simple hemagglutination assay to 30.6% positivity when the same samples were treated with phospholipase C. Similarly, reverse transcription-PCR was a much better M-41 detection tool as compared with the classical agar gel precipitation assay utilized to screen tissue homogenates from IBV-positive chickens. In conclusion, this survey clearly demonstrates that several strains of IBV are prevalent in poultry flocks in Pakistan. By utilizing such diagnostic techniques it is possible to conduct a detailed epidemiological study to determine the full economic impact of this disease.
本研究旨在调查巴基斯坦商业肉鸡和蛋鸡群中传染性支气管炎病毒（IBV）的发病率。使用血凝抑制试验，针对M-41、D-274、D-1466和4-91株抗原对来自16个蛋鸡群和9个肉鸡群的血清样本进行了筛查。总体而言，88%的鸡群M-41抗体呈血清阳性，而分别有40%、52%和8%的鸡群D-274、D-1466和4-91 IBV株呈阳性。在临床确诊的传染性支气管炎病例的肺和气管组织中也检测到了M-41抗原。对IBV阳性鸡的肺和气管组织匀浆进行磷脂酶C处理后，在简单血凝试验中M-41株的检出限从1.3%阳性样本提高到用磷脂酶C处理相同样本时的30.6%阳性率。同样，与用于筛查IBV阳性鸡组织匀浆的经典琼脂凝胶沉淀试验相比，逆转录PCR是一种更好的M-41检测工具。总之，本次调查清楚地表明，巴基斯坦家禽群中流行多种IBV毒株。通过使用此类诊断技术，有可能开展详细的流行病学研究，以确定该疾病的全面经济影响。
