Bovine parainfluenza-3 virus (BPIV-3) is one of the main viruses associated with bovine respiratory disease complex (BRDC) worldwide. BPIV-3 infect the bovine respiratory tract causing from subclinical infections to severe pneumonia with significant economic losses in the cattle industry. BPIV-3 is a RNA virus with high genetic variability, nevertheless, the contribution of recombination events to its variability has not been assessed so far. In this study the 25 complete genome sequences (CGS) reported so far and 215 partial sequences of different viral genes of BPIV-3 were analyzed to determine their genotypes and subgenotypes, distribution, and the existence of potential recombination events. Based on the analysis of the HN, M, N, and P genes one hypothetical subgenotype was found (subgenotype A4). Four recombination events between sequences of swine and cattle were detected by RDP4 analysis in conjunction with phylogenetic incongruences in the L gene. In addition, 9 sequences reported from Argentina were found to be miss-classified. These results reveal that homologous recombination events have a relevant role in the evolution of BPIV-3 and highlight the importance of implement advanced molecular characterization to better understand the variability and evolution of BPIV-3 as a component of BRDC.

牛副流感 3 病毒 (BPIV-3) 是全球与牛呼吸系统疾病 (BRDC) 相关的主要病毒之一。BPIV-3 感染牛呼吸道，导致从亚临床感染到严重肺炎，给养牛业带来重大经济损失。BPIV-3 是一种具有高遗传变异性的 RNA 病毒，然而，迄今为止尚未评估重组事件对其变异性的贡献。在这项研究中，对迄今为止报道的 25 个完整基因组序列 (CGS) 和 BPIV-3 不同病毒基因的 215 个部分序列进行了分析，以确定它们的基因型和亚基因型、分布以及潜在重组事件的存在。根据对 HN、M、N 和 P 基因的分析，发现了一种假设的亚基因型（亚基因型 A4）。猪和牛的序列之间的四个重组事件通过 RDP4 分析结合 L 基因的系统发育不一致进行检测。此外，发现阿根廷报告的 9 个序列被错误分类。这些结果表明同源重组事件在 BPIV-3 的进化中具有相关作用，并强调了实施高级分子表征以更好地了解 BPIV-3 作为 BRDC 组成部分的变异性和进化的重要性。