Molecular Mechanisms of Staphylococcus aureus Pathogenicity

Staphylococcus aureus employs a multifaceted arsenal of molecular strategies to colonise tissues, evade host defences and establish infection. Surface adhesins mediate attachment to host extracellular matrix components such as collagen and fibronectin, initiating colonisation. Secretion of proteases and collagenases degrades host barriers, while specialised transporters import liberated nutrients including proline to fuel the tricarboxylic acid cycle and sustain oxidative metabolism. Central metabolic pathways are tightly integrated with virulence regulation: the agr quorum-sensing system and two-component regulators such as SrrAB sense environmental cues (oxygen tension, reactive oxygen species) and modulate toxin and biofilm gene expression. Biofilm formation, underpinned by extracellular polysaccharide synthesis and programmed cell lysis, promotes chronic infection and resistance to immune clearance. Host immunometabolic responses, notably itaconate production by stressed phagocytes, feed back on bacterial metabolism to select for strains with enhanced biofilm capacity. Together these mechanisms enable S. aureus to adapt to diverse host niches, resist antimicrobial therapies and drive both acute and persistent disease worldwide.

Research from Nature Portfolio

Recent studies have shown that clinical isolates of S. aureus adapt to fibrotic lung environments by upregulating collagenase and proline transport genes. Degradation of host collagen liberates proline, which is then imported and channelled into the tricarboxylic acid cycle, enhancing bacterial fitness in chronic pulmonary infection. Another investigation has revealed that airway immune cells release itaconate in response to staphylococcal glycolysis. Itaconate inhibits bacterial glycolytic enzymes, selecting for variants that redirect carbon flux towards extracellular polysaccharide production and form robust biofilms, thereby promoting persistence in the chronically infected airway.

Molecular Mechanisms of Staphylococcus aureus Pathogenicity publication trend

The graph below shows the total number of articles in molecular mechanisms of staphylococcus aureus pathogenicity across all publications each year (not limited to Nature Index journals).

Technical terms

Quorum sensing: Cell-to-cell signalling mechanism by which bacteria coordinate gene expression in response to population density.

Two-component regulatory system: Signal transduction module comprising a membrane sensor kinase and a response regulator that adjusts gene transcription.

Biofilm: Structured community of bacteria encased in a self-produced extracellular matrix, conferring resistance to immune factors and antibiotics.

Tricarboxylic acid cycle (TCA cycle): Central metabolic pathway in aerobic organisms that oxidises acetyl-CoA to generate ATP and biosynthetic precursors.

Itaconate: Host-derived immunometabolite produced by immune cells that inhibits bacterial glycolysis and influences pathogen adaptation.

Extracellular polysaccharide: Sugar polymer secreted by bacteria to form the biofilm matrix and protect against environmental stresses.

References

1. Staphylococcus aureus adapts to exploit collagen-derived proline during chronic infection. Nature Microbiology (2024).
2. Quorum-sensing agr system of Staphylococcus aureus primes gene expression for protection from lethal oxidative stress. eLife (2024).
3. Amino Acid Catabolism in Staphylococcus aureus and the Function of Carbon Catabolite Repression. mBio (2017).
4. Impaired respiration elicits SrrAB-dependent programmed cell lysis and biofilm formation in Staphylococcus aureus. eLife (2017).
5. Staphylococcus aureus induces an itaconate-dominated immunometabolic response that drives biofilm formation. Nature Communications (2021).