Bovine papular stomatitis (BPS) generally is a mild viral disease caused by the Bovine papular stomatitis virus (BPSV) belonging to the genus Parapoxvirus (PPV). This study aimed to perform the first molecular characterization and phylogenetic analysis of BPSV in beef calves in Iran. Clinical examinations were carried out on four beef cattle herds in West Azerbaijan province, which had experienced outbreaks of papular lesions. Fifty swab samples were collected from the papular lesions on the muzzle, lips, and oral cavity of affected calves, and after viral DNA extraction, they were subjected to polymerase chain reaction (PCR). The results of PCR confirmed the presence of BPSV in all calves with clinical symptoms. The partial B2L gene was sequenced based on nucleotides, and phylogenetic analysis was performed using MEGA 11.0.13. The analysis revealed that BPSV isolates from beef calves in Iran formed two clades. Clade 1 exhibited similarities to the isolates from Finland, Japan, and Georgia, while Clade 2 was similar to the Zambian isolates. These findings indicate the presence of genetic diversity and potential variability within the virus population. Further studies with larger sample sizes and diverse geographic regions will increase the resolution of the phylogenetic tree and contribute to a comprehensive understanding of how BPSV circulates in the country.

牛丘疹性口炎（BPS）通常是由属于副痘病毒（PPV）属的牛丘疹性口炎病毒（BPSV）引起的轻度病毒性疾病。本研究旨在对伊朗肉牛中的 BPSV 进行首次分子表征和系统发育分析。对西阿塞拜疆省的四个肉牛群进行了临床检查，这些肉牛群曾爆发过丘疹性病变。从受影响犊牛口吻、嘴唇和口腔的丘疹病变处采集50份拭子样本，提取病毒DNA后进行聚合酶链反应（PCR）。PCR结果证实所有有临床症状的犊牛均存在BPSV。基于核苷酸对部分B2L基因进行测序，并使用MEGA 11.0.13进行系统发育分析。分析显示，从伊朗牛犊中分离出的 BPSV 菌株形成了两个分支。进化枝 1 与芬兰、日本和格鲁吉亚的分离株表现出相似性，而进化枝 2 则与赞比亚分离株相似。这些发现表明病毒种群内存在遗传多样性和潜在变异性。更大样本量和不同地理区域的进一步研究将提高系统发育树的分辨率，并有助于全面了解 BPSV 如何在该国传播。