Molecular mechanisms of resistance and tolerance of Staphylococcus aureus to daptomycin

Area of Science:

• Microbiology
• Pharmacology
• Biochemistry

Background:

• Daptomycin is a key lipopeptide antibiotic for Gram-positive infections, particularly Staphylococcus aureus.
• It functions by binding bacterial membranes and disrupting cell integrity, but resistance and tolerance limit its efficacy.
• Mechanisms of resistance, such as MprF mutations, alter cell surface charge, hindering daptomycin's action.

Purpose of the Study:

• To review the molecular mechanisms underlying daptomycin resistance and tolerance in Staphylococcus aureus.
• To explore the interplay between resistance pathways and signal transduction systems.
• To highlight the understudied aspect of daptomycin tolerance.

Main Methods:

• Literature review of existing studies on daptomycin resistance and tolerance.
• Analysis of molecular pathways, including genetic mutations and cell envelope modifications.
• Examination of signal transduction crosstalk.

Main Results:

• Daptomycin resistance in S. aureus is often mediated by mutations in MprF, leading to increased lysyl-phosphatidylglycerol and a positive cell surface charge.
• Higher daptomycin concentrations can induce further modifications, including peptidoglycan alterations, to reduce drug efficacy.
• Overlapping pathways exist between daptomycin resistance and tolerance, with tolerance being less understood.

Conclusions:

• Daptomycin resistance and tolerance in S. aureus are complex, multifactorial processes.
• Understanding these mechanisms is essential for developing strategies to combat treatment failures.
• Further research into daptomycin tolerance is warranted.