Antibiotic bactericidal action mainly has four mechanisms: inhibition of bacterial cell wall synthesis, interaction with cell membranes, interference with protein synthesis, and inhibition of nucleic acid transcription and replication inhibition.
Process of action
(1) Inhibition of cell wall synthesis
The inhibition of the synthesis of cell walls leads to the death of bacterial cells. The antibiotics that act in this way include penicillins and cephalosporins. Mammalian cells have no cell walls and are not affected by these drugs. The bacterial cell wall is mainly peptidoglycans, and the organelles that synthesize peptide chains are ribosomes, which are the sole organelles of bacteria. However, frequent use will lead to increased bacterial resistance.
The achievement of this effect relies on a protein in the bacterial cell wall, commonly known as penicillin-binding proteins (PBPs), which bind to this protein and thereby inhibit the synthesis of cell walls, so PBPs are also targets of this class of drugs. point.
(2) Interaction with cell membranes
Some antibiotics interact with the cell membrane of cells and affect membrane permeability, which has a fatal effect on cells. Antibiotics that act in this way are polymyxins and bacilli.
(3) Interfering protein synthesis
Interfering with protein synthesis means that the enzymes necessary for cell survival cannot be synthesized. Antibiotics that interfere with protein synthesis include famycins (actinomycins), aminoglycosides, tetracyclines, and chloramphenicol.
(4) Suppression of nucleic acid transcription and replication inhibition
Suppression of Transcription and Replication of Nucleic Acids The function of inhibiting nucleic acids prevents cell division and/or the synthesis of desired enzymes. Antibiotics that act in this way include nalidixic acid and dichloroacridine.