规模化驴场中马流感病毒H3N8亚型感染情况调查

Prevalence of Equine Influenza Virus H3N8 Subtype Infection in Large-scale Donkey Farms

[目的]调查山东省聊城市规模化驴场中马流感病毒的感染情况,并分析其可能的来源。[方法]从聊城的规模化驴场采集病料和血清,通过HI试验检测驴血清中的马流感病毒H3N8亚型抗体的阳性率。使用RT-PCR技术扩增肺脏和鼻腔棉拭子样品中的马流感病毒M基因,对获得的马流感病毒M基因与不同流感病毒的M基因进行序列比对,推测其来源。[结果]HI试验表明,120个血清样品中马流感病毒H3N8亚型血清抗体阳性率为33.3%(40/120);其中,母驴的马流感病毒H3N8亚型血清抗体阳性率为42.5%(17/40)、公驴为32.5%(13/40)、驴驹为25.0%(10/40)。通过RT-PCR检测发现,32.3%(21/65)的样品可测出目的条带。通过序列比对得出,该试验获得的流感病毒M基因与马属动物的H3N8亚型流感病毒高度同源(CY032222、CY032318、CY028821等),同源性最高可达99.8%。[结论]马流感病毒在聊城周边的数个规模化养驴场发生流行。该研究从驴体内分离的流感病毒M基因属于马流感病毒H3N8亚型M基因。

[Objective] To investigate the infection status of equine influenza virus in large-scale donkey farms in Liaocheng City of Shandong Province, and to identify the possible sources of the virus.[Method] Clinical samples were collected from the large-scale donkey farms in Liaocheng City. The positive rate of serum antibodies against H3N8 subtype of equine influenza virus was determined by HI test. RT-PCR was used to amplify the M gene of equine influenza virus in lungs and nasal swabs. The obtained M gene was sequenced and compared with the M gene of different influenza viruses to infer its origin.[Result] HI test showed that the positive rate of equine influenza virus H3N8 subtype in 120 serum samples was 33.3%(40/120). The positive rate for female donkeys, male donkeys and donkey foals was 42.5%(17/40), 32.5%(13/40) and 25.0%(10/40), respectively. RT-PCR assay demonstrated that 32.3%(21/65) of the samples was detected as positive for the presence of M gene. The M gene obtained in this study is highly homologous to H3N8 subtype influenza virus of equine (CY032222, CY032318, CY028821, etc.), with the highest homology of 99.8%.[Conclusion] Equine influenza virus is prevalent in several large-scale donkey farms around Liaocheng City. The M gene of influenza virus obtained from donkeys in this study belongs to the M gene of H3N8 subtype of equine influenza virus.