Characteristic Differences in Reverse Transcription-Polymerase Chain Reaction Products of Ovine, Bovine, and Human Respiratory Syncytial Viruses

In reverse transcription-polymerase chain reactions (RT-PCR) and DNA hybridizations using primers and an oligonucleotide probe to the fusion (F) protein mRNA of bovine respiratory syncytial virus (BRSV), all the BRSV isolates and a goat isolate could be distinguished from prototype isolates of human respiratory syncytial viruses (HRSV) and ovine (sheep and bighorn sheep) respiratory syncytial viruses (RSV). However, RT-PCR amplifications with primers to sequences of the HRSV F protein mRNA resulted in amplified products of approximately 243 bp if mRNA templates of subgroup A HRSV strains were present and slightly larger amplified products with subgroup B HRSV strains. No amplified products were observed in HRSV-primed RT-PCR with BRSV or goat or ovine RSV mRNA templates. Although the ovine RSV isolates were antigenically cross-reactive with the goat RSV, HRSV and BRSV isolates, they were no amplified with either HRSV- or BRSV-specific primers in RT-PCR. These results confirm previous immunological comparisons suggesting that some ovine RSV isolates should be considered as distinct respiratory syncytial viruses.