Uropathogenic Escherichia coli bacterial membrane lipids (UPEC membrane lipids)

Uropathogenic Escherichia coli (UPEC) bacterial membrane lipids are fundamental components of the bacterial cell envelope, comprising the inner cytoplasmic membrane and the outer membrane (OM). The OM is an asymmetric bilayer where the outer leaflet is primarily composed of lipopolysaccharides (LPS), while the inner leaflet contains phospholipids such as phosphatidylethanolamine and phosphatidylglycerol [1]. These lipids serve as a critical permeability barrier, protecting the bacterium from host immune defenses, such as antimicrobial peptides and bile salts, and are essential for the anchoring of virulence factors like fimbriae [2]. In the context of urinary tract infections (UTIs), UPEC lipids facilitate survival in the nutrient-poor and osmotically stressful environment of the bladder and kidneys [3]. Therapeutic strategies targeting these lipids often involve cationic antibiotics like polymyxins, which bind to the negatively charged Lipid A moiety of LPS, causing membrane destabilization and cell death [4]. However, the clinical utility of these drugs is constrained by nephrotoxicity and the potential for inducing septic shock through the massive release of endotoxins during bacterial lysis [5]. References: [1] Silhavy et al. (2010) Cold Spring Harb Perspect Biol; [2] Terlizzi et al. (2017) Front Microbiol; [3] Klein & Hultgren (2020) Nat Rev Microbiol; [4] Trimpa et al. (2022) Antibiotics; [5] Poirel et al. (2017) Clin Microbiol Rev.

Other names

UPEC cell envelope lipidsUPEC membrane componentsUropathogenic E. coli lipidsUPEC outer membrane lipids

Polymyxins and other cationic antimicrobial peptides interact electrostatically with the negatively charged phosphate groups of Lipid A in the outer membrane lipopolysaccharides, displacing stabilizing divalent cations and leading to membrane permeabilization and cell lysis [4].