Quantitative method for determining the lateral strength of bacterial adhesion and application for characterizing adhesion kinetics.
A quantitative method for measuring the shear force required to detach individual adhered bacteria using atomic force microscopy (AFM) was developed. By determining the total compression of the cantilever during cell detachment events, a more accurate means of calculating the applied lateral force necessary to remove individual cells was achieved compared to previous methods. In addition, a tunable assay for monitoring the dynamics of Pseudomonas aeruginosa and Staphylococcus aureus adhesion strength was employed. The accumulation of force measurements over time allowed for the characterization of adhesion strength kinetics. P. aeruginosa reinforced its adhesion to the surface at a rate 7-fold faster than for S. aureus; the average adhesion strength of P. aeruginosa was larger than that of S. aureus at corresponding time points. Adhered cells of the same species and strain demonstrated a range of adhesion forces that broadened with time, indicating that the change in adhesion strength does not proceed uniformly.
Deupree
Susan M
SM
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Schoenfisch
Mark H
MH
D001422:Bacterial Adhesion; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007700:Kinetics; D050296:Microbial Viability; D018625:Microscopy, Atomic Force / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000648:ultrastructure; D013314:Stress, Mechanical