Evaluation of a nested reverse transcription-PCR assay based on the nucleoprotein gene for diagnosis of spontaneous and experimental bovine respiratory syncytial virus infections.
The first nested reverse transcription (RT)-PCR based on the nucleoprotein gene (n RT-PCR-N) of the bovine respiratory syncytial virus (BRSV) has been developed and optimized for the detection of BRSV in bronchoalveolar lavage fluid cells of calves. This test is characterized by a low threshold of detection (0.17 PFU/ml), which is 506 times lower than that obtained by an enzyme immunosorbent assay (EIA) test (RSV TESTPACK ABBOTT). During an experimental infection of 17 immunocompetent calves less than 3 months old, BRSV RNA could be detected up to 13 days after the onset of symptoms whereas isolation in cell culture was possible only up to 5 days. Compiling results obtained by conventional techniques (serology, antigen detection, and culture isolation) for 132 field samples collected from calves with acute respiratory signs revealed that n RT-PCR-N showed the highest diagnostic sensitivity and very good specificity. This n RT-PCR-N with its long period of detection during BRSV infection thus provides a valuable tool for diagnostic and epidemiological purposes.
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000821:virology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D002478:Cells, Cultured; D005814:Genes, Viral; D008168:Lung / Q000821:virology; D015203:Reproducibility of Results; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000662:veterinary*; D018112:Respiratory Syncytial Virus, Bovine / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D015678:Viral Structural Proteins / Q000235:genetics