title: Detection and seroprevalence of infectious bronchitis virus strains in commercial poultry in Pakistan.
abstract: 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.
authors.affiliation: National Reference Laboratory for Poultry Diseases, Animal Sciences Institute, National Agricultural Research Center, Park Road, Islamabad, Pakistan. drzaheeer@comsats.net.pk
authors.forename: Z
authors.initials: Z
authors.lastname: Ahmed
authors.forename: K
authors.initials: K
authors.lastname: Naeem
authors.forename: A
authors.initials: A
authors.lastname: Hameed
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D018352:Coronavirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D001351:Infectious bronchitis virus / Q000145:classification* / Q000302:isolation & purification*; D008168:Lung / Q000821:virology; D010154:Pakistan / Q000453:epidemiology; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology*; D016036:Seroepidemiologic Studies; D014132:Trachea / Q000821:virology