Mechanisms of Microbial Adhesion and Biofilm Formation

Microorganisms colonise surfaces through a series of coordinated steps that begin with reversible attachment via physicochemical forces and progress to permanent adhesion mediated by specialised surface proteins. In Gram-positive bacteria, microbial surface components recognising adhesive matrix molecules (MSCRAMMs) bind host extracellular matrix proteins, while Gram-negative species often employ pili and lectins to secure attachment. Following irreversible adhesion, cells proliferate and secrete an extracellular polymeric substance (EPS) matrix composed of exopolysaccharides, proteins, extracellular DNA and lipids. This matrix fosters microcolony formation and the development of three-dimensional biofilm architectures, complete with fluid channels that enable nutrient distribution and waste removal. Biofilm development is governed by regulatory networks including quorum sensing and cyclic di-nucleotide signalling, and is modulated by mechanical forces such as shear stress and catch-bond interactions. Mature biofilms exhibit enhanced tolerance to antimicrobial agents and host immune responses, posing persistent challenges in clinical, industrial and environmental settings. Ultimately, cells disperse from the matrix, facilitating spread to new niches. Recent advances in single-cell force spectroscopy, high-resolution imaging and molecular genetics have elucidated the interplay between mechanical stability, regulatory circuits and matrix composition, guiding the design of anti-biofilm surfaces and targeted therapeutics to curb biofouling and antibiotic resistance.

Research from Nature Portfolio

Recent work has uncovered a mechanosensitive catch bond formed by a bacterial surface protein and a host complement regulator. Under increasing tensile force, the adhesin undergoes a conformational transition that strengthens binding through extended hydrogen-bond networks, delaying bond rupture at forces exceeding one nanonewton. This “dock-lock-latch” mechanism illustrates how pathogens exploit mechanical stress to evade immunity and reinforce biofilm anchorage, offering a novel target for anti-adhesion therapies.

Mechanisms of Microbial Adhesion and Biofilm Formation publication trend

The graph below shows the total number of articles in mechanisms of microbial adhesion and biofilm formation across all publications each year (not limited to Nature Index journals).

Technical terms

Adhesin: A cell-surface molecule that mediates specific attachment to biotic or abiotic substrates.

MSCRAMM: Microbial surface component recognising adhesive matrix molecules; a family of Gram-positive adhesins that bind host extracellular matrix proteins.

Catch bond: A non-intuitive receptor–ligand interaction whose lifetime increases under mechanical force.

Exopolysaccharide (EPS): Polysaccharide polymers secreted by microbes that form the scaffold of the biofilm matrix.

Quorum sensing: A cell-to-cell communication process by which bacteria coordinate gene expression in response to population density.

References

1. Alpha-hemolysin promotes internalization of Staphylococcus aureus into human lung epithelial cells via caveolin-1- and cholesterol-rich lipid rafts. Cellular and Molecular Life Sciences (2024).
2. High-force catch bonds between the Staphylococcus aureus surface protein SdrE and complement regulator factor H drive immune evasion. Communications Biology (2023).
3. Staphylococcal Adhesion and Host Cell Invasion: Fibronectin-Binding and Other Mechanisms. Frontiers in Microbiology (2017).
4. The Multivalent Role of Fibronectin-Binding Proteins A and B (FnBPA and FnBPB) of Staphylococcus aureus in Host Infections. Frontiers in Microbiology (2020).