French Andrea J, Rockey Nicole C, Sage Valerie Le, Brown Karina Mueller, Shephard Meredith J, Frizzell Sheila, Myerburg Mike M, Hiller N Luisa, Lakdawala Seema S
Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA.
bioRxiv. 2023 Feb 25:2023.02.24.529988. doi: 10.1101/2023.02.24.529988.
Secondary infection with has contributed significantly to morbidity and mortality during multiple influenza virus pandemics and remains a common threat today. During a concurrent infection, both pathogens can influence the transmission of each other, but the mechanisms behind this are unclear. In this study, condensation air sampling and cyclone bioaerosol sampling were performed using ferrets first infected with the 2009 H1N1 pandemic influenza virus (H1N1pdm09) and secondarily infected with strain D39 (Spn). We detected viable pathogens and microbial nucleic acid in expelled aerosols from co-infected ferrets, suggesting that these microbes could be present in the same respiratory expulsions. To assess whether microbial communities impact pathogen stability within an expelled droplet, we performed experiments measuring viral and bacterial persistence in 1 μL droplets. We observed that H1N1pdm09 stability was unchanged in the presence of Spn. Further, Spn stability was moderately increased in the presence of H1N1pdm09, although the degree of stabilization differed between airways surface liquid collected from individual patient cultures. These findings are the first to collect both pathogens from the air and in doing so, they provide insight into the interplay between these pathogens and their hosts.
The impact of microbial communities on transmission fitness and environmental persistence is under-studied. Environmental stability of microbes is crucial to identifying transmission risks and mitigation strategies, such as removal of contaminated aerosols and decontamination of surfaces. Co-infection with is very common during influenza virus infection, but little work has been done to understand whether alters stability of influenza virus, or vice versa, in a relevant system. Here, we demonstrate that influenza virus and are expelled by co-infected hosts. Our stability assays did not reveal any impact of on influenza virus stability, and a trend towards increased stability of in the presence of influenza viruses. Future work characterizing environmental persistence of viruses and bacteria should include microbially-complex solutions to better mimic physiologically relevant conditions.
在多次流感病毒大流行期间，继发感染已对发病率和死亡率产生了重大影响，并且至今仍是一个常见威胁。在同时感染期间，两种病原体可相互影响传播，但背后的机制尚不清楚。在本研究中，对先感染2009年甲型H1N1流感大流行病毒（H1N1pdm09）并继发感染肺炎链球菌D39菌株（Spn）的雪貂进行了冷凝空气采样和旋风生物气溶胶采样。我们在共同感染的雪貂呼出的气溶胶中检测到了活病原体和微生物核酸，这表明这些微生物可能存在于相同的呼吸道排出物中。为了评估微生物群落是否会影响呼出液滴内病原体的稳定性，我们进行了测量1μL液滴中病毒和细菌持久性的实验。我们观察到在有Spn存在的情况下，H1N1pdm09的稳定性没有变化。此外，在有H1N1pdm09存在的情况下，Spn的稳定性适度增加，尽管从个体患者培养物中收集的气道表面液体之间的稳定程度有所不同。这些发现首次从空气中收集到两种病原体，并且这样做能够深入了解这些病原体与其宿主之间的相互作用。
微生物群落对传播适应性和环境持久性的影响研究不足。微生物的环境稳定性对于确定传播风险和缓解策略（如去除受污染的气溶胶和对表面进行去污）至关重要。在流感病毒感染期间，与肺炎链球菌的共同感染非常常见，但在相关系统中，对于肺炎链球菌是否会改变流感病毒的稳定性，或者反之亦然，几乎没有开展相关研究。在这里，我们证明共同感染的宿主会排出流感病毒和肺炎链球菌。我们的稳定性测定未发现肺炎链球菌对流感病毒稳定性有任何影响，并且在流感病毒存在的情况下有肺炎链球菌稳定性增加的趋势。未来表征病毒和细菌环境持久性的工作应包括微生物复杂溶液，以更好地模拟生理相关条件。
