Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
mSphere. 2022 Jun 29;7(3):e0004622. doi: 10.1128/msphere.00046-22. Epub 2022 May 9.
Enteric viruses encounter various bacteria in the host, which can impact infection outcomes. The interactions between noroviruses and enteric bacteria are not well understood. Previous work determined that murine norovirus (MNV), a model norovirus, had decreased replication in antibiotic-treated mice compared with conventional mice. Although this suggests that the microbiota promotes MNV infection, the mechanisms are not completely understood. Additionally, prior work with other enteric viruses, such as poliovirus and coxsackievirus B3, demonstrated that virions bind bacteria, and exposure to bacteria stabilizes viral particles and limits premature RNA release. Therefore, we examined interactions between MNV and specific bacteria and the consequences of these interactions. We found that the majority of Gram-positive bacteria tested stabilized MNV, while Gram-negative bacteria did not stabilize MNV. Both Gram-positive and Gram-negative bacteria bound to MNV. However, bacterial binding alone was not sufficient for virion stabilization, since Gram-negative bacteria bound MNV but did not stabilize virions. Additionally, we found that bacteria conditioned medium also stabilized MNV and this stabilization may be due to a small heat-stable molecule. Overall, this work identifies specific bacteria and bacterial components that stabilize MNV and may impact virion stability in the environment. Enteric viruses are exposed to a wide variety of bacteria in the intestine, but the effects of bacteria on viral particles are incompletely understood. We found that murine norovirus (MNV) virion stability is enhanced in the presence of several Gram-positive bacterial strains. Virion-stabilizing activity was also present in bacterial culture medium, and activity was retained upon heat or protease treatment. These results suggest that certain bacteria and bacterial products may promote MNV stability in the environment, which could influence viral transmission.
肠病毒在宿主体内遇到各种细菌，这可能会影响感染结果。诺如病毒和肠道细菌之间的相互作用尚未得到充分理解。先前的研究表明，鼠诺如病毒（MNV）作为一种模式诺如病毒，在抗生素处理的小鼠中复制能力较普通小鼠降低。尽管这表明微生物群促进了 MNV 感染，但机制尚不完全清楚。此外，先前针对其他肠道病毒（如脊髓灰质炎病毒和柯萨奇病毒 B3）的研究表明，病毒粒子与细菌结合，而暴露于细菌会使病毒颗粒稳定并限制 RNA 过早释放。因此，我们研究了 MNV 与特定细菌之间的相互作用及其后果。我们发现，大多数测试的革兰氏阳性菌稳定了 MNV，而革兰氏阴性菌则不能稳定 MNV。革兰氏阳性菌和革兰氏阴性菌都与 MNV 结合。然而，细菌结合本身不足以稳定病毒粒子，因为革兰氏阴性菌与 MNV 结合但不能稳定病毒粒子。此外，我们发现细菌条件培养基也能稳定 MNV，这种稳定作用可能归因于一种小的热稳定分子。总的来说，这项工作确定了特定的细菌和细菌成分可以稳定 MNV，并且可能影响环境中病毒粒子的稳定性。肠病毒在肠道中暴露于各种细菌，但细菌对病毒粒子的影响尚未完全了解。我们发现，鼠诺如病毒（MNV）病毒粒子的稳定性在存在几种革兰氏阳性菌菌株的情况下增强。在细菌培养基中也存在病毒稳定活性，并且该活性在热或蛋白酶处理后仍保留。这些结果表明，某些细菌和细菌产物可能在环境中促进 MNV 的稳定性，从而影响病毒的传播。
