The biophysics of bacterial infections: adhesion events in the light of force spectroscopy

Abstract Bacterial infections are the most eminent public health challenge of the 21st century. The primary step leading to infection is bacterial adhesion to host cells or surfaces, which is mediated by a multitude of molecular interactions. At the interface of life sciences and physics, the massive advances seen over the last years in atomic force microscopy (AFM) techniques have made possible to measure the forces driving the cell-cell and cell-substrate interactions on a single cell basis (single molecule/cell force spectroscopy). Among the bacterial cell-surface interactions, the life-threatening infections associated to medical devices involving Staphylococcus aureus and Escherichia coli are the most eminent. Also, classical examples of cell-cell interactions that lead to serious infections are the Pseudomonas aeruginosa binding to the pulmonary and urinary tract or the Helicobacter pylori binding to the gastric mucosa. AFM techniques allow further understanding of the cell-cell and cell-surface interactions. As we approach the end of the antibiotic era, acquisition of a deeper knowledge of the fundamental forces involved in microbial cells adhesion is crucial not only to know the ligand-binding events but also to identify novel therapeutic targets for design of novel anti-infective strategies. The aim of this mini-review is to briefly highlight how force spectroscopy is depicting biophysical features of some emergent bacterial pathogens and how it has been contributing to the design of novel therapeutics, namely within bioengineered approaches.