Antibiotics and Carbohydrate-Containing Drugs Targeting Bacterial Cell Envelopes: An Overview

Abstract

Certain bacteria constitute a threat to humans due to their ability to escape host defenses as they easily develop drug resistance. Bacteria are classified into gram-positive and gram-negative according to the composition of the cell membrane structure. Gram-negative bacteria have an additional outer membrane (OM) that is not present in their gram-positive counterpart; the latter instead hold a thicker peptidoglycan (PG) layer. This review covers the main structural and functional properties of cell wall polysaccharides (CWPs) and PG. Drugs targeting CWPs are discussed, both noncarbohydrate-related (β-lactams, fosfomycin, and lipopeptides) and carbohydrate-related (glycopeptides and lipoglycopeptides). Bacterial resistance to these drugs continues to evolve, which calls for novel antibacterial approaches to be developed. The use of carbohydrate-based vaccines as a valid strategy to prevent bacterial infections is also addressed.

Experimental evidence of d‐glutamate racemase activity in the uncultivated bacterium Candidatus Saccharimonas aalborgensis

“…Based on this property, the investigation of this macromolecule continues to be an active area of research in aspects related to its structure and associated enzymology (Daitch & Goley, 2020; Vollmer et al, 2008). Information gained in this area is fundamental for the discovery of new inhibitors with therapeutical value (Riu et al, 2022). On other grounds, metagenomics is increasing exponentially our view of the microbial world with a diversity much larger than anticipated.…”

Enhancing the Antimicrobial Properties of Peptides through Cell-Penetrating Peptide Conjugation: A Comprehensive Assessment

“…Generally, the mechanisms by which AMPs act against bacteria depend on the properties of the bacterial cell wall. Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have an outer membrane and a thinner peptidoglycan layer, which can impact the effectiveness of different antimicrobial strategies [54,55]. Interestingly, only peptides containing the TAT fragment as CPP showed the greatest antimicrobial effect against S. aureus, MRSA, and P. aeruginosa.…”

“…Tat fragment (RKKRRQRRR) and Antennapedia peptide (RQIKIWFQNRRMKWKK) are among the first CPPs that were identified in the 1990s and have since been used as membranotropic molecules, including for the creation of antimicrobial peptides [21][22][23]. Derived from the Antennapedia homeodomain from Drosophila, Antennapedia peptide is a 16-residue peptide [RQIKIWFQNRRMKWKK (43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)] employed as a vector for the cellular uptake of hydrophilic molecules [21,24,25]. Further results demonstrated that among all tested peptides, Antennapedia peptide is a promising antibacterial peptide with high selectivity and less cytotoxicity for mammalian cells that could be further applied as a delivery system for antibacterial agent delivery [26,27].…”

Treatments of Mycobacterium tuberculosis and Toxoplasma gondii with Selenium Nanoparticles

“…These characteristics are part of the bacterial classification, which is based on differences in cell wall structures. Thus, the cell wall of gram-negative bacteria has a thin layer of peptidoglycan with an additional outer membrane consisting of lipopolysaccharide [ 187 ]. On the other hand, the cell wall of gram-positive bacteria is typically thicker and is mainly composed of peptidoglycans [ 112 , 188 ].…”