Instituto de Física, Universidade de São Paulo, São Paulo, 05508090, SP, Brazil.
Núcleo de Pesquisas em Doenças Negligenciadas, Universidade Guarulhos, Guarulhos, 07023‑070, SP, Brazil.
Sci Rep. 2024 Oct 4;14(1):23055. doi: 10.1038/s41598-024-74056-6.
Schistosoma mansoni, an intravascular parasitic worm and the causative agent of schistosomiasis, relies on its tegument (outer layer) for survival and host interaction. This study explored the morphology and mechanical properties of S. mansoni tegument using Atomic Force Microscopy (AFM). Notably, we employed the PeakForce Quantitative Nanomechanical Mapping (PF-QNM) mode in air, enabling simultaneous acquisition of 3D topography and mechanical property contrasts (adhesion, elastic modulus). Additionally, nanoindentation (AFM contact mode) was performed on female worm tegument for elastic modulus measurement. Both techniques revealed an elastic modulus range of fractions or units of GPa for the tegument. Interestingly, mechanical property maps, particularly adhesion contrast, displayed a recurring pattern of light and dark bands. We also measured the depth of annular furrows on the female tegument, finding an average of 128 ± 10 nm. These findings establish AFM, particularly PF-QNM, as a valuable tool to characterize S. mansoni tegument properties, offering insights for future investigations into parasite biology and its response to immunological or pharmacological challenges.
曼氏血吸虫是一种血管内寄生蠕虫，也是血吸虫病的病原体，它依赖其表皮（外层）来生存和与宿主相互作用。本研究使用原子力显微镜（AFM）探索了曼氏血吸虫表皮的形态和力学特性。值得注意的是，我们在空气中采用了峰值力定量纳米力学测绘（PF-QNM）模式，能够同时获取 3D 形貌和力学特性对比（粘附力、弹性模量）。此外，我们还对雌性虫体的表皮进行了纳米压痕（AFM 接触模式）以测量弹性模量。这两种技术都揭示了表皮的弹性模量范围在几分之一或单位 GPa 之间。有趣的是，力学特性图谱，特别是粘附力对比，显示出明暗相间的周期性条纹。我们还测量了雌性表皮上环形凹槽的深度，发现平均为 128±10nm。这些发现确立了 AFM，特别是 PF-QNM，作为一种有价值的工具来描述曼氏血吸虫表皮特性，为未来研究寄生虫生物学及其对免疫或药物挑战的反应提供了新的视角。
