Murakami Daichi, Kono Masamitsu, Nanushaj Denisa, Kaneko Fumie, Zangari Tonia, Muragaki Yasuteru, Weiser Jeffrey N, Hotomi Muneki
Department of Otorhinolaryngology-Head and Neck Surgery, Wakayama Medical University, Wakayama, Japan.
Department of Otolaryngology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan.
Front Cell Infect Microbiol. 2021 Mar 31;11:651495. doi: 10.3389/fcimb.2021.651495. eCollection 2021.
, one of the most common commensal pathogens among children, is spread by close contact in daycare centers or within a family. Host innate immune responses and bacterial virulence factors promote pneumococcal transmission. However, investigations into the effects of environmental factors on transmission have been limited. Passive smoking, a great concern for children's health, has been reported to exacerbate pneumococcal diseases. Here, we describe the effect of cigarette smoke exposure on an infant mouse model of pneumococcal transmission. Our findings reveal that the effect of cigarette smoke exposure significantly promotes pneumococcal transmission by enhancing bacterial shedding from the colonized host and by increasing susceptibility to pneumococcal colonization in the new host, both of which are critical steps of transmission. Local inflammation, followed by mucosal changes (such as mucus hypersecretion and disruption of the mucosal barrier), are important underlying mechanisms for promotion of transmission by smoke exposure. These effects were attributable to the constituents of cigarette smoke rather than smoke itself. These findings provide the first experimental evidence of the impact of environmental factors on pneumococcal transmission and the mechanism of pathogenesis.
肺炎链球菌是儿童中最常见的共生病原体之一，可通过日托中心或家庭中的密切接触传播。宿主的先天免疫反应和细菌毒力因子促进肺炎链球菌的传播。然而，关于环境因素对传播影响的研究一直有限。被动吸烟是儿童健康的一大担忧，据报道会加剧肺炎链球菌疾病。在此，我们描述了香烟烟雾暴露对肺炎链球菌传播的幼鼠模型的影响。我们的研究结果表明，香烟烟雾暴露的影响通过增强定殖宿主的细菌脱落以及增加新宿主对肺炎链球菌定殖的易感性，显著促进了肺炎链球菌的传播，而这两个过程都是传播的关键步骤。局部炎症，随后是黏膜变化（如黏液分泌过多和黏膜屏障破坏），是烟雾暴露促进传播的重要潜在机制。这些影响归因于香烟烟雾的成分而非烟雾本身。这些发现提供了环境因素对肺炎链球菌传播影响及其发病机制的首个实验证据。
