Abstract:
Bovine parainfluenza virus type 3 (BPIV-3) is one of the major pathogens of the bovine respiratory disease complex (BRDC). BPIV-3 surveillance in China has been quite limited. In this study, we used PCR to test 302 cattle in China, and found that the positive rate was 4.64% and the herd-level positive rate was 13.16%. Six BPIV-3C strains were isolated and confirmed by electron microscopy, and their titers were determined. Three were sequenced by next-generation sequencing (NGS). Phylogenetic analyses showed that all isolates were most closely related to strain NX49 from Ningxia; the genetic diversity of genotype C strains was lower than strains of genotypes A and B; the HN, P, and N genes were more suitable for genotyping and evolutionary analyses of BPIV-3. Protein variation analyses showed that all isolates had mutations at amino acid sites in the proteins HN, M, F, and L. Genetic recombination analyses provided evidence for homologous recombination of BPIV-3 of bovine origin. The virulence experiment indicated that strain Hubei-03 had the highest pathogenicity and could be used as a vaccine candidate. These findings apply an important basis for the precise control of BPIV-3 in China.
摘要:
牛副流感病毒3型(BPIV-3)是牛呼吸道疾病复合体(BRDC)的主要病原体之一。BPIV-3在中国的监测相当有限。在这项研究中,我们用PCR检测了中国的302头牛,发现阳性率为4.64%,羊群水平阳性率为13.16%。分离出6株BPIV-3C菌株,并通过电子显微镜证实,并确定了它们的滴度。通过下一代测序(NGS)对三个进行测序。系统发育分析表明,所有分离株与宁夏NX49菌株的亲缘关系最密切;基因型C菌株的遗传多样性低于基因型A和B菌株;HN,P,和N基因更适合BPIV-3的基因分型和进化分析。蛋白质变异分析表明,所有分离株在蛋白质HN的氨基酸位点都有突变,M,F,遗传重组分析为牛来源的BPIV-3的同源重组提供了证据。毒力实验表明,湖北-03菌株的致病性最高,可作为候选疫苗。这些发现为中国BPIV-3的精确控制提供了重要依据。