Chen Qichao, Lin Yanfeng, Wang Kaiying, Li Jinhui, Li Peng, Song Hongbin
Department of Pulmonary and Critical Care Medicine, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou 225000, China.
Chinese PLA Center for Disease Control and Prevention, Beijing 100071, China.
Microorganisms. 2025 Jul 21;13(7):1709. doi: 10.3390/microorganisms13071709.
Secondary methicillin-resistant (MRSA) infection causes high mortality in patients with influenza A virus (IAV). Our previous study observed that the relative abundance of () was significantly reduced in both the respiratory tract and gut of IAV-infected mice and negatively correlated with the severity of IAV-MRSA coinfection pneumonia, but the role of remains unclear. Here, we supplemented the respiratory tract and gut of IAV-infected mice with live and performed a secondary MRSA infection challenge to investigate the effects and potential mechanisms further. Data showed that supplementation significantly reduced mortality and pathogen loads in IAV-MRSA coinfected mice and upregulated the lung T cell-independent (TI) IgA response in IAV-infected mice. The 16S rRNA gene sequencing results showed that supplementation ameliorated microbiota composition disorder and regulated metabolic dysfunction in the gut of IAV-infected mice. The correlation analysis and antibiotic cocktail treatment experiment showed that the TI IgA response in lungs is dependent on gut microbiota. These findings demonstrated that supplementation reduces susceptibility to secondary MRSA infection in IAV-infected mice by promoting the TI IgA response, and provide a new perspective on the use of probiotics to prevent secondary bacterial infection following IAV infection.
继发性耐甲氧西林金黄色葡萄球菌（MRSA）感染在甲型流感病毒（IAV）患者中导致高死亡率。我们之前的研究观察到，在IAV感染小鼠的呼吸道和肠道中，（此处原文缺失相关内容）的相对丰度显著降低，且与IAV-MRSA合并感染肺炎的严重程度呈负相关，但（此处原文缺失相关内容）的作用仍不清楚。在此，我们用活的（此处原文缺失相关内容）补充IAV感染小鼠的呼吸道和肠道，并进行继发性MRSA感染挑战以进一步研究其影响和潜在机制。数据显示，补充（此处原文缺失相关内容）显著降低了IAV-MRSA合并感染小鼠的死亡率和病原体载量，并上调了IAV感染小鼠肺部非T细胞依赖性（TI）IgA反应。16S rRNA基因测序结果表明，补充（此处原文缺失相关内容）改善了IAV感染小鼠肠道中的微生物群组成紊乱并调节了代谢功能障碍。相关性分析和抗生素鸡尾酒治疗实验表明，肺部的TI IgA反应依赖于肠道微生物群。这些发现证明，补充（此处原文缺失相关内容）通过促进TI IgA反应降低了IAV感染小鼠对继发性MRSA感染的易感性，并为使用益生菌预防IAV感染后的继发性细菌感染提供了新的视角。
