一起荷斯坦奶牛乳头瘤病诊断及其病毒基因型分析

Diagnosis of Papilloma and Genotype Characterization of the Bovine Papillomavirus from Holstein Milk Cows in Gansu Province,China

牛乳头瘤病毒是一种能够引起牛发生皮肤乳头状瘤、纤维素瘤、膀胱和食道癌的DNA病毒,现已在牛群中广泛传播,对牛养殖业造成了重大经济损失。为了诊断甘肃某荷斯坦奶牛场300多头泌乳期奶牛乳头突发疣状物的病因,本研究采用流行病学调查、临床观察、组织病理学、分子生物学检测方法和基因测序技术,对患有疣状物的奶牛进行综合诊断。结果表明,乳头患疣状物奶牛的其它部位无类似生长物,无发烧、疼痛等异常临床症状,组织病理学HE检测疣状物呈现角化过度和细胞空泡化现象,这与牛乳头瘤病毒感染的组织病理变化相似,并且用PCR方法获得了牛乳头状瘤病毒L1基因,测序比对结果显示为乳头瘤病毒7型基因,核苷酸同源性达98%以上。因此,本次荷斯坦奶牛乳头突发疣状物为乳头瘤病毒7型感染引起的,这是甘肃地区首次发现该基因型乳头瘤病毒,应引起奶牛场与防疫部门的重视。

The bovine papillomavirus(BPV)is a non-enveloped DNA virus that causes skin papilloma/fibroma and bladder/esophageal cancer in cattle. Such diseases have spread widely in herds and resulted in significant economic losses. We wished to ascertain the reason for teat warts in ~300 Holstein milk cows from Gansu Province in China. Epidemiological investigations,clinical observations,histopathology,molecular biology and sequencing were carried out. Results demonstrated that the warts were found only in teats,and the abnormal clinical symptoms such as fever and pain were not appeared. Histopathology examination revealed that the teat warts were due to exaggerated hyperkeratosis and epidermal cells cavitation. These histopathological changes were similar to those observed in cows infected with the BPV. L1 genome of BPV were amplified from two teat warts collected from clinical samples(named GSHZ/12/2019)and showed more than 98% identity with the reference sequence of the BPV-7 genotype. Therefore,this outbreak in cow herds was associated with BPV-7 related infections. This is the first report of BPV -7 infection in Holstein milk cows in Gansu Province,China,and should arise much attention for dairy farms and epidemic prevention departments.