Overcoming the rising incidence and evolving mechanisms of antibiotic resistance by novel drug delivery approaches – An overview

This graphical abstract provides an overview of the major bacterial resistance mechanisms. The critical difference between the structure Gram-positive (Left) and Gram-negative bacteria (Right) lies in their cell wall composition. Bacteria confer resistance to antibiotics through four major mechanisms: (1) Antibiotic degrading enzymes directly inactivating the antibiotics by modifying their chemical structures; (2) Decrease the intracellular antibiotic concentrations by decreasing or loss of porins, to prevent the antibiotics to enter the intracellular space, and by actively pumping the antibiotics out to the extracellular space. (3) By modifying the target sites for antibiotics, the antibiotics can no longer disrupt the bacterial cell function. The antibiotic target sites can be in ribosomes, DNA replication enzymes, and cell wall precursors. (4) The target sites can be prevented from antibiotics access to antibiotics by for example, modifying the bacterial surface charge. LPS – Lipopolysaccharide.