Pathogenesis of Influenza D Virus in Cattle
Pathogenesis of Influenza D Virus in Cattle
复制标题
DOI：
10.1128/jvi.03122-15
复制
发表时间：
2016-06-01
影响因子：
5.4
通讯作者：
Wan, Xiu-Feng
中科院分区：
文献类型：
--
作者：
Ferguson, Lucas;Olivier, Alicia K.;Wan, Xiu-Feng
牛已被认为是正粘病毒科一个新成员的天然宿主，该病毒被初步归类为D型流感病毒(IDV)。虽然IDV是从患病动物身上分离出来的，但目前还不清楚IDV是否会在牛身上引起任何临床疾病。为了解决科赫假设的这一方面，对三头单独圈养的小牛(处理动物)进行了鼻腔接种IDV毒株D/牛/密西西比/C00046N/2014。在接种后1天，在每个处理动物圈中添加一头血清阴性的小牛(接触动物)。治疗组和接触组的牛血清转换，并在它们的呼吸道中检测到病毒。组织学上，与对照动物相比，处理组小牛气管上皮细胞中性粒细胞的踪迹显著增加。虽然感染和接触的动物表现出各种呼吸道感染的症状，但它们都是轻微的，治疗组的牛犊在心率、呼吸频率和直肠温度方面与对照组没有差异。为了模拟人畜共患病的传播，两只雪貂被暴露在一个塑料玩具中，其中浸泡了从治疗牛犊那里流出的受感染的鼻液。这些雪貂没有排出病毒，也没有血清转换。综上所述，这项研究表明，IDV在实验感染牛时会引起一种轻微的呼吸道疾病，并可通过围栏内接触在牛之间有效传播，但不能通过接触甲虫在牛与雪貂之间传播。这些发现支持牛是病毒的天然宿主的假设。在猪、牛、绵羊和山羊中发现了一种新的流感病毒，暂定为D型流感病毒(IDV)。在这些宿主中，牛被认为是天然的水库。在这项研究中，我们证明了实验感染IDV的牛可以传播病毒并通过直接接触传播给其他牛，但不能通过福尔马特途径传播给雪貂。IDV在受感染的牛身上引起了轻微的临床症状，满足了科赫对这种新制剂的另一个假设，尽管其他客观的临床终点与对照动物没有什么不同。虽然观察到的疾病是轻微的，但IDV在牛的气管内诱导了中性粒细胞的示踪和上皮的衰减，这可能会促进与其他病原体的混合感染，从而使动物容易患上牛呼吸道疾病。
Cattle have been proposed as the natural reservoir of a novel member of the virus family Orthomyxoviridae, which has been tentatively classified as influenza D virus (IDV). Although isolated from sick animals, it is unclear whether IDV causes any clinical disease in cattle. To address this aspect of Koch's postulates, three dairy calves (treatment animals) held in individual pens were inoculated intranasally with IDV strain D/bovine/Mississippi/C00046N/2014. At 1 day postinoculation, a seronegative calf (contact animal) was added to each of the treatment animal pens. The cattle in both treatment and contact groups seroconverted, and virus was detected in their respiratory tracts. Histologically, there was a significant increase in neutrophil tracking in tracheal epithelia of the treatment calves compared to control animals. While infected and contact animals demonstrated various symptoms of respiratory tract infection, they were mild, and the calves in the treatment group did not differ from the controls in terms of heart rate, respiratory rate, or rectal temperature. To mimic zoonotic transmission, two ferrets were exposed to a plastic toy fomite soaked with infected nasal discharge from the treatment calves. These ferrets did not shed the virus or seroconvert. In summary, this study demonstrates that IDV causes a mild respiratory disease upon experimental infection of cattle and can be transmitted effectively among cattle by in-pen contact, but not from cattle to ferrets through fomite exposure. These findings support the hypothesis that cattle are a natural reservoir for the virus.IMPORTANCEA novel influenza virus, tentatively classified as influenza D virus (IDV), was identified in swine, cattle, sheep, and goats. Among these hosts, cattle have been proposed as the natural reservoir. In this study, we show that cattle experimentally infected with IDV can shed virus and transmit it to other cattle through direct contact, but not to ferrets through fomite routes. IDV caused minor clinical signs in the infected cattle, fulfilling another of Koch's postulates for this novel agent, although other objective clinical endpoints were not different from those of control animals. Although the disease observed was mild, IDV induced neutrophil tracking and epithelial attenuation in cattle trachea, which could facilitate coinfection with other pathogens, and in doing so, predispose animals to bovine respiratory disease.