Staphylococcus aureus cytoplasmic membrane (S. aureus CM)

The Staphylococcus aureus cytoplasmic membrane is a vital phospholipid bilayer that serves as a selective permeability barrier and the primary site for essential metabolic processes, including ATP generation and cell wall precursor synthesis (Kilelee et al., 2010, PMC2852145). It is composed primarily of branched-chain fatty acids and phospholipids such as phosphatidylglycerol and lysyl-phosphatidylglycerol, which regulate the membrane's net charge and fluidity. As a therapeutic target, the membrane is highly significant because its disruption leads to rapid, bactericidal effects that are often independent of the bacterial growth phase. Clinically important drugs like daptomycin target this structure by inserting into the membrane in a calcium-dependent manner, causing depolarization and ion leakage (Humphries et al., 2013, PMC3676289). Other agents, such as the lipoglycopeptide telavancin, interact with membrane-anchored Lipid II to simultaneously inhibit cell wall synthesis and destabilize membrane integrity (Saravolatz et al., 2009, CID). Understanding the composition and dynamics of this membrane is crucial for addressing antibiotic resistance, particularly in methicillin-resistant S. aureus (MRSA) strains where membrane modifications can lead to reduced drug binding.

Other names

Staphylococcus aureus plasma membraneStaphylococcus aureus inner membraneBacterial cytoplasmic membrane

Drugs targeting the cytoplasmic membrane typically act by binding to specific components such as Lipid II or inserting into the lipid bilayer in a calcium-dependent manner. This insertion leads to membrane depolarization, pore formation, and the rapid leakage of intracellular ions like potassium (K+). The resulting loss of membrane potential causes the cessation of DNA, RNA, and protein synthesis, leading to rapid bacterial cell death without requiring cell lysis.