Isolation of a Divergent Strain of Bovine Parainfluenza Virus Type 3 (BPIV3) Infecting Cattle in China

Abstract

Bovine parainfluenza virus type 3 (BPIV3) is one of the most important known viral respiratory pathogens of both young and adult cattle. It is also named "heat stress in transport", causing morbidity and mass death. New variants of BPIV3 have been detected or isolated in China since 2008. Here, we isolate one BPIV3 strain (named BPIV3 BJ) in Madin-Darby bovine kidney (MDBK) cells from nasal samples collected in China. Phylogenetic analysis showed that our isolate is related to BPIV3 of the genotype A. The comparison of BPIV3-BJ and the reference Chinese isolate NM09 showed that these strains are highly divergent. We found many differences in the amino acid composition in the nucleocapsid (NP) protein among these genotype A strains. Since the NP protein has been implicated in immunization studies, our BPIV3 isolate will be useful for the development of immune assays and vaccine studies. The diversity of BPIV3 lineages that we found in China indicated ongoing evolution for immune escape. Our study highlights the importance of genetic surveillance for determining the effect of BPIV3 variability on pathogen evolution and population-scale immunity.

Keywords: MDBK cells; biotechnology; bovine parainfluenza virus; cattle; phylogenetic analysis; vaccine.

Figure 1

PCR detection of bovine viral diarrhea virus (BVDV), bovine parainfluenza virus type 3 (BPIV3), bovine alphaherpesvirus 1 (BHV-1), and bovine respiratory syncytial virus (BRSV) by PCR. Lane M was a 2000 bp DNA marker (DNA marker shown from top to bottom as 2000 bp, 1000 bp, 750 bp, 500 bp, 250 bp, and 100 bp); lanes 1, 12, 23, and 34 were negative controls; lanes 2–11 were ten nasal samples for BPIV3 detection, respectively; lanes 13–22 were ten nasal samples for BVDV detection, respectively; lanes 24–33 were ten nasal samples for BRSV detection, respectively; lanes 35–44 were ten nasal samples for BHV-1 detection, respectively.

Figure 2

The cytopathic effect (CPE) of BPIV3-BJ in Madin-Darby bovine kidney (MDBK) cells: (A). The controlled MDBK cells; (B). the MDBK cells infected by BPIV3-BJ.

Figure 3

Phylogenetic trees constructing complete genomes of bovine parainfluenza virus. Phylogenetic tree constructed using 24 genomic sequences of BPIV3. The tree was inferred using a maximum composite likelihood (MCL) approach assuming the HKY model plus a discrete Gamma correction and the rate of invariable sites. Values above branches indicate bootstrap support after 500 replications. The BIPV3 strain in this work is indicated by an open rectangle in the tree. Numbers within each gray rectangle are the genetic distances and standard errors of strains of each genotype (i.e., genotype A, B, and C). Phylogenetic analyses and estimation of genetic distances were conducted using MEGAX software.