Hariharan Vishnu, Chowdhury Atish Roy, Rao S Srinivas, Chakravortty Dipshikha, Basu Saptarshi
Department of Mechanical Engineering, Indian Institute of Science, Bangalore, Karnataka State 560012, India.
Department of Microbiology & Cell Biology, Indian Institute of Science, Bangalore, Karnataka State 560012, India.
iScience. 2023 Apr 8;26(5):106580. doi: 10.1016/j.isci.2023.106580. eCollection 2023 May 19.
Despite extensive studies on kinematic features of impacting drops, the effect of mechanical stress on desiccated bacteria-laden droplets remains unexplored. In the present study, we unveiled the consequences of the impaction of bacteria-laden droplets on solid surfaces and their subsequent desiccation on the virulence of an enteropathogen typhimurium (STM). The methodology elucidated the deformation, cell-cell interactions, adhesion energy, and roughness in bacteria induced by impact velocity and low moisture because of evaporation. retrieved from the dried droplets were used to understand fomite-mediated pathogenesis. The impact velocity-induced mechanical stress deteriorated the viability of . Of interest, an uninterrupted bacterial proliferation was observed in macrophages at higher mechanical stress. Wild-type under mechanical stress induced the expression of whereas infecting macrophages. The inability of STM to grow in nutrient-rich dried droplets signifies the role of in sensing the mechanical stress and maintaining the virulence of .
尽管对冲击液滴的运动学特征进行了广泛研究，但机械应力对干燥的载菌液滴的影响仍未得到探索。在本研究中，我们揭示了载菌液滴撞击固体表面及其随后干燥对肠道病原菌鼠伤寒沙门氏菌（STM）毒力的影响。该方法阐明了由于蒸发导致的冲击速度和低湿度所引起的细菌变形、细胞间相互作用、粘附能和粗糙度。从干燥液滴中提取的物质用于了解污染物介导的发病机制。冲击速度引起的机械应力降低了STM的活力。有趣的是，在较高机械应力下，巨噬细胞中观察到细菌持续增殖。在机械应力下，野生型STM在感染巨噬细胞时会诱导某物质的表达。STM无法在营养丰富的干燥液滴中生长，这表明该物质在感知机械应力和维持STM毒力方面的作用。
