SUBGROUPING OF BOVINE RESPIRATORY SYNCYTIAL VIRUS-STRAINS DETECTED INLUNG-TISSUE

Bovine respiratory syncytial virus is an important respiratory pathoge n in cattle. Recently, subgroups of BRSV have been identified, based o n antigenic differences. However, little is known about subgroups of B RSV that circulate in the cattle population, Therefore, we determined the reactivity of monoclonal antibodies (mAbs), directed against the G , F, or P protein of BRSV, with lung tissue from 47 calves, that suffe red from severe respiratory disease. Fourteen animals (30%) proved to be infected with BRSV, because they all reacted with mAbs against the P qr F protein, as detected by fluorescent antibody tests. Monoclonal antibodies against the G protein were able to discriminate between the BRSV-positive specimens: 7 strains were identified as subgroup A stra ins, and 5 strains as subgroup AB, which is introduced as BRSV subgrou p in this paper. Two strains could not be identified unambiguously. It is concluded that BRSV subgroup A and AB were associated with severe respiratory disease, and that strains belonging to either subgroup cir culated concurrently in the cattle population in the Netherlands.