Bacterial and fungal cell envelopes

The bacterial and fungal cell envelopes are complex, multi-layered structures that provide physical protection, maintain osmotic pressure, and regulate the transport of molecules into and out of the cell [NIH, Wikipedia]. In bacteria, the envelope typically consists of a cytoplasmic membrane and a peptidoglycan cell wall, with Gram-negative species possessing an additional outer membrane containing lipopolysaccharides [StatPearls, NIH]. Fungal envelopes comprise a plasma membrane containing ergosterol and a rigid cell wall made of chitin, glucans, and mannoproteins [StatPearls, PubMed]. These structures are critical for microbial survival and virulence, making them primary targets for various classes of antimicrobial agents [StatPearls]. Because many components of these envelopes, such as peptidoglycan and ergosterol, are absent in human cells, they offer high therapeutic indices for treating infections [StatPearls, NIH]. However, the broad nature of this 'target' reflects a diverse array of specific molecular sites, and the emergence of resistance remains a significant clinical challenge [PubMed]. Drugs targeting these envelopes include beta-lactams, glycopeptides, polyenes, and echinocandins, each addressing different biochemical pathways within the envelope structure [StatPearls, PubMed].

Other names

Microbial cell envelopeBacterial cell wallFungal cell wallMicrobial cell membraneMicrobial envelope

Drugs targeting these structures typically act by inhibiting the synthesis of essential components such as peptidoglycan in bacteria or beta-glucan in fungi, binding to and disrupting the lipid bilayer, or sequestering essential sterols like ergosterol to compromise membrane stability [StatPearls, PubMed].