The First Case in Japan of Bovine Respiratory Disease Caused by the Isolates of the Genotype C Bovine Parainfluenza Virus Type 3

Abstract

Bovine parainfluenza virus type 3 (BPIV3) isolates are classified into three genotypes (BPIV3a to c). In 2012, two BPIV3 (HS8 and HS9) strains were isolated from the nasal swabs of cattle kept on two farms in Hiroshima Prefecture. The results of partial genome sequence analysis revealed that the two strains belonged to different genotypes. While the HS8 strain was classified as BPIV3a, the HS9 strain was classified as BPIV3c, which is the latest genotype of BPIV3. This is the first report of BPIV3c isolates in Japan. The low level of the sequence identity of the P gene between the HS9 and BPIV3a isolates suggested that the current RT-PCR method will fail to detect BPIV3c strains. Thus, appropriate primers that can detect all the genotypes need to be designed.