atomic force microscope (asylum research mfp-3d  (Asylum Research Inc)

Journal: NPJ Biofilms and Microbiomes

Article Title: Bacterial–host adhesion dominated by collagen subtypes remodelled by osmotic pressure

doi: 10.1038/s41522-024-00600-x

Figure Lengend Snippet: A Schematic diagram of interactions between bacteria and cells in the intestinal microenvironment. B Schematic diagram of an in vitro model of bacterial interaction with epithelial cells under different osmotic pressures. The host cells were cultured for 12 h in regular culture medium and then stimulated for 1 h in a specific osmotic mixture. Then, they were allowed to interact with GFP-expressing S. aureus or E. coli for another 2 h and rinsed three times with Dulbecco’s phosphate-buffered saline (DPBS) solution. Finally, the osmoregulated bacterium‒cell interactions were quantified. C Images of GFP-expressing S. aureus adherent/internalized to IEC-6 cells after the host cells were prestimulated with hypotonic (0.5x), isotonic (1x), and hypertonic (2x) solutions, which were acquired with a laser scanning confocal microscope. The F-actin cytoskeleton was labeled in red by rhodamine phalloidin, and the nuclei were labeled in blue by DAPI. D and E Statistical results of the number of bacteria adherent/internalized to host cells ( N adB ) and the number of host cells harboring adherent/internalized bacteria ( N adC ) in microscopy images with an imaging field of view of 337 × 337 μm 2 , where the host cells were prestimulated with hypotonic (0.5x), isotonic (1x), and hypertonic (2x) solutions, respectively. F and G Fold changes in N adB and N adC under hypertonic and hypotonic conditions relative to the indices in the isotonic situation. (H) Statistical results of the number of host cells harboring adherent/internalized bacteria ( N adC (%)) quantified through flow cytometry. I – N are similar to C – H , respectively, except that the host cells were replaced with the HaCat cell line. All the statistical data (mean ± SD) originated from at least three independent experiments for each specific condition. Statistical analyses based on one-way ANOVA were used in the experiments, and **, *** and **** denote P < 0.01, P < 0.001 and P < 0.0001, respectively. Scale bar: 50 μm.

Article Snippet: An atomic force microscope (AFM, Asylum Research MFP-3D) was utilized to characterize the surface roughness and stiffness of the host cells.

Techniques: Bacteria, In Vitro, Cell Culture, Expressing, Saline, Microscopy, Labeling, Imaging, Flow Cytometry