Comparison of targeting F and G protein genes to detect bovine and ovine respiratory syncytial viruses.

Eleraky, Nasser Z; Kania, Stephen A; Evermann, James F; Potgieter, Leon N D

In this study, 2 reverse transcriptase-polymerase chain reaction (RT-PCR) assays were developed and compared for simultaneous detection of bovine and ovine respiratory syncytial viruses (RSVs). One assay was based on a set of primers, which amplified a 426-bp fragment of either bovine or ovine RSV F gene (RT-PCR F). The F products could be distinguished by EcoRI or BstYI restriction endonuclease cleavage. In the other assay, a set of primers amplified a 542-bp fragment of either ovine or bovine RSV G gene (RT-PCR G). EcoO1091 and RsaI restriction enzymes were used to differentiate between the ovine and bovine PCR-G products. Sequencing of the PCR products confirmed the fidelity of both assays. The 2 assays were evaluated using 18 bovine RSV isolates, 1 ovine RSV, 1 bighorn sheep RSV isolate, 1 caprine RSV isolate, 2 human RSV isolates, and several other viruses associated with bovine respiratory tract disease. RT-PCR G may be more sensitive in detecting viral RNA. Because the target sequence of the F gene is more conserved than that of the G gene, RT-PCR F followed by the appropriate restriction enzyme cleavage may be superior to RT-PCR G to discriminate between the 2 ruminant RSV subgroups. This assay should prove useful for determining the relative contribution of ovine and bovine RSV to the pathogenesis of bovine respiratory tract disease.