Bacterial and fungal cell wall polysaccharides

Bacterial and fungal cell wall polysaccharides are essential structural polymers that maintain cell shape and protect microorganisms from osmotic lysis and environmental stressors. In bacteria, the primary component is peptidoglycan, a mesh-like layer of sugar chains cross-linked by peptides, while fungal walls are composed of a complex matrix of chitin, beta-glucans, and mannoproteins (Gow et al., 2017, Nature Reviews Microbiology). Because these specific polysaccharide structures are absent in human biology, they serve as ideal targets for selective antimicrobial therapy. Drugs such as glycopeptides (e.g., vancomycin) function by binding directly to the D-alanyl-D-alanine terminus of peptidoglycan precursors, effectively blocking the assembly of the cell wall (Binda et al., 2014, Natural Product Reports). Similarly, polymyxins target the lipopolysaccharides in the outer membrane of Gram-negative bacteria to disrupt membrane integrity (Landman et al., 2008, Clinical Microbiology Reviews). Beyond their structural importance, these polysaccharides act as pathogen-associated molecular patterns (PAMPs) that trigger host immune responses through pattern recognition receptors like Dectin-1 and TLR4 (Brown et al., 2012, Science). Consequently, they are also utilized as clinical biomarkers, such as (1,3)-beta-D-glucan and galactomannan, to diagnose invasive fungal infections (Ostrosky-Zeichner et al., 2005, Clinical Infectious Diseases).

Other names

PeptidoglycanChitinBeta-glucanMannanLipopolysaccharideMureinCell wall glycansCapsular polysaccharides

Direct binding to cell wall structural components or their immediate precursors to inhibit polymerization, cross-linking, or membrane stability.