Université de Toulouse, ENVT, INRAE, UMR 1225, Toulouse, France.
Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
J Virol. 2020 May 4;94(10). doi: 10.1128/JVI.00289-20.
Ducks usually show little or no clinical signs following highly pathogenic avian influenza virus infection. In order to analyze whether the microbiota could contribute to the control of influenza virus replication in ducks, we used a broad-spectrum oral antibiotic treatment to deplete the microbiota before infection with a highly pathogenic H5N9 avian influenza virus. Antibiotic-treated ducks and nontreated control ducks did not show any clinical signs following H5N9 virus infection. We did not detect any significant difference in virus titers neither in the respiratory tract nor in the brain nor spleen. However, we found that antibiotic-treated H5N9 virus-infected ducks had significantly increased intestinal virus excretion at days 3 and 5 postinfection. This was associated with a significantly decreased antiviral immune response in the intestine of antibiotic-treated ducks. Our findings highlight the importance of an intact microbiota for an efficient control of avian influenza virus replication in ducks. Ducks are frequently infected with avian influenza viruses belonging to multiple subtypes. They represent an important reservoir species of avian influenza viruses, which can occasionally be transmitted to other bird species or mammals, including humans. Ducks thus have a central role in the epidemiology of influenza virus infection. Importantly, ducks usually show little or no clinical signs even following infection with a highly pathogenic avian influenza virus. We provide evidence that the microbiota contributes to the control of influenza virus replication in ducks by modulating the antiviral immune response. Ducks are able to control influenza virus replication more efficiently when they have an intact intestinal microbiota. Therefore, maintaining a healthy microbiota by limiting perturbations to its composition should contribute to the prevention of avian influenza virus spread from the duck reservoir.
鸭通常在感染高致病性禽流感病毒后几乎没有或没有任何临床症状。为了分析微生物组是否有助于控制鸭中的流感病毒复制，我们在感染高致病性 H5N9 禽流感病毒之前使用广谱口服抗生素治疗来耗尽微生物组。感染 H5N9 病毒后，抗生素处理的鸭和未经处理的对照鸭均未出现任何临床症状。我们在呼吸道、大脑或脾脏中均未检测到病毒滴度有任何显著差异。然而，我们发现抗生素处理的 H5N9 病毒感染的鸭在感染后第 3 天和第 5 天的肠道病毒排泄量明显增加。这与抗生素处理的鸭的肠道中抗病毒免疫反应明显降低有关。我们的研究结果强调了完整的微生物组对于控制鸭中禽流感病毒复制的重要性。鸭经常感染属于多种亚型的禽流感病毒。它们是禽流感病毒的重要储存宿主物种，偶尔会传播给其他鸟类或哺乳动物，包括人类。因此，鸭在流感病毒感染的流行病学中起着核心作用。重要的是，即使感染了高致病性禽流感病毒，鸭通常也几乎没有或没有任何临床症状。我们提供的证据表明，微生物组通过调节抗病毒免疫反应来控制鸭中的流感病毒复制。当鸭具有完整的肠道微生物组时，它们能够更有效地控制流感病毒复制。因此，通过限制对其组成的干扰来维持健康的微生物组应该有助于防止禽流感病毒从鸭储存库传播。
