Comprehensive virulence profiling and evolutionary analysis of specificity determinants in Staphylococcus aureus...

Area of Science:

• Microbiology
• Bacterial genetics
• Molecular biology

Background:

• Two-component systems (TCSs) are crucial for bacterial adaptation and virulence.
• Staphylococcus aureus, particularly the USA300 strain, relies on TCSs for survival and pathogenesis.
• Understanding TCSs is vital for developing novel antimicrobial strategies against drug-resistant bacteria.

Purpose of the Study:

• To investigate the complex interplay between TCSs in S. aureus USA300.
• To identify shared and unique virulence regulatory pathways mediated by TCSs.
• To explore genetic variations influencing signal specificity within TCSs.

Main Methods:

• Utilized TCS-related mutants from the Nebraska Transposon Mutant Library.
• Assessed the impact of inactivated TCS histidine kinases (HKs) and response regulators (RRs) on virulence factors, in vitro infection, and adhesion.
• Employed structural analysis of DesK-DesR and modeled NarL TCSs to identify specificity determinants.

Main Results:

• TCS influence on virulence was not correlated with phylogenetic relationships, suggesting divergent functional evolution.
• Identified conserved and varied interacting residues within TCSs across different strains and species.
• Revealed specificity determinants governing HK-RR interactions.

Conclusions:

• TCSs exhibit complex interplay and divergent functional evolution in S. aureus virulence regulation.
• Specificity determinants within TCSs are conserved within strains but vary between species.
• Further exploration of TCS phosphotransfer holds potential for antimicrobial development.