Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Lavale, Pune, Maharashtra, 412115, India.
Arch Microbiol. 2023 Jul 4;205(8):273. doi: 10.1007/s00203-023-03612-x.
Respiratory tract is a complex system comprising of unique microbiota inhabitants. Neisseria meningitidis, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Klebsiella pneumoniae are few prevalent bacteria in the community composition during lung infections. Although, N. meningitidis resides asymptomatically in nasopharynx of the human host, it can cause fatal infections like meningitis. However, factors affecting transit from carriage to symptomatic infection are not well understood. Various host metabolites and environmental conditions affect the virulence of bacteria. Here, we report that presence of co-colonizers significantly reduces the initial attachment of N. meningitidis to A549 nasopharyngeal epithelial cells. Further, significant decrease in invasion to A549 nasopharyngeal epithelial cells was observed. Moreover, survival in J774A.1 murine macrophage also increases significantly when conditioned media (CM) from S. pyogenes and L. rhamnosus is used for culturing N. meningitidis. The increase in survival could be attributed to increased capsule synthesis. The gene expression studies revealed increased expression of siaC and ctrB in CM prepared from the growth S. pyogenes and L. rhamnosus. Overall, the results suggest change in the virulence of N. meningitidis is assisted by lung microbiota.
呼吸道是一个复杂的系统，包含独特的微生物群落。脑膜炎奈瑟菌、金黄色葡萄球菌、化脓性链球菌、铜绿假单胞菌和肺炎克雷伯菌是肺部感染时社区组成中常见的几种细菌。尽管脑膜炎奈瑟菌在人类宿主的鼻咽部无症状存在，但它可引起致命的感染，如脑膜炎。然而，从携带到症状性感染的转移的影响因素尚不清楚。各种宿主代谢物和环境条件会影响细菌的毒力。在这里，我们报告说，共同定植菌的存在显著降低了脑膜炎奈瑟菌初始附着在 A549 鼻咽上皮细胞上的能力。此外，观察到脑膜炎奈瑟菌对 A549 鼻咽上皮细胞的侵袭明显减少。此外，当使用化脓性链球菌和鼠李糖乳杆菌的条件培养基（CM）培养脑膜炎奈瑟菌时，在 J774A.1 鼠巨噬细胞中的存活也显著增加。存活增加可归因于荚膜合成增加。基因表达研究表明，在由化脓性链球菌和鼠李糖乳杆菌生长制备的 CM 中 siaC 和 ctrB 的表达增加。总的来说，这些结果表明，肺部微生物群有助于改变脑膜炎奈瑟菌的毒力。
