Microbial cell envelope components

Microbial cell envelope components encompass the complex multi-layered structures that protect bacteria and fungi from environmental stress and osmotic pressure (Silhavy et al., 2010, Cold Spring Harb Perspect Biol). In bacteria, this includes the peptidoglycan cell wall, the inner cytoplasmic membrane, and, in Gram-negative species, an outer membrane containing lipopolysaccharides (LPS) (Silhavy et al., 2010, Cold Spring Harb Perspect Biol). Fungal envelopes consist of a cell membrane containing ergosterol and a rigid wall made of chitin and glucans (Gow et al., 2017, Nat Rev Microbiol). These components are vital for microbial survival, making them primary targets for many classes of antimicrobial agents (Kohanski et al., 2010, Nat Rev Microbiol). For instance, beta-lactams and glycopeptides inhibit cell wall synthesis, while polymyxins and lipopeptides target membrane integrity (Kohanski et al., 2010, Nat Rev Microbiol). Because many of these structures, such as peptidoglycan and specific glucans, are absent in human cells, they provide a high degree of selective toxicity for treating infections (Odds et al., 2003, J Antimicrob Chemother). However, the emergence of multi-drug resistant organisms and the potential for host toxicity with certain membrane-disrupting agents remain significant clinical challenges. These components also serve as critical pathogen-associated molecular patterns (PAMPs) that trigger the host's innate immune response during an infection.

Other names

Bacterial cell wallBacterial cell membraneFungal cell wallCell envelopeMicrobial surface components

Drugs targeting these components typically act by inhibiting the biosynthesis of essential structural polymers like peptidoglycan or beta-glucan, or by directly disrupting the physical integrity and permeability of the lipid membranes, leading to cell lysis and death (Kohanski et al., 2010, Nat Rev Microbiol).