Probing Membrane Biomechanics of Erythrocytes Parasitized by <italic>Salmonella paratyphi B</italic> Using Atomic Force Microscopy

Abstract

Parasitization by Salmonella paratyphi B ( Sp B ) leads to morphological, structural, biochemical component, and mechanical deformation alterations to the host erythrocytes. To probe these modifications at the nanoscale, we apply atomic force microscopy and diffraction phase microscopy to measure the mechanical properties of red blood cell (RBC) membrane infected by Sp B , including deformability, shear modulus and bending modulus. Combining the two techniques with a new mathematical model describing RBC membrane is very sensitive to the invader of parasitic Sp B . The results demonstrated that the growing parasite in their host RBCs caused structure changes and decreased deformation. Coincident with this morphological transition, there is a significant increase in the membrane's shear and bending moduli. This mechanical transition can alter cell circulation and impede oxygen delivery. The results indicated that proteins transported from invading organisms, such as the Ivirulent parasitic Sp B , to specific binding sites in the spectrin network are considered to introduce significant alterations to RBC membrane skeleton network, dynamics and mechanical response. These changes could provide insights into possible mechanistic pathways in the pathogenesis of parasitic Sp B , which may provide new ideas on further experiments and analyses.