What is the mode of action of antimicrobial drugs?

Answer 1

Different antibiotics have different modes of action, owing to the nature of their structure and degree of affinity to certain target sites within bacterial cells.

Inhibitors of cell wall synthesis.

A drug that targets cell walls can therefore selectively kill or inhibit bacterial organisms. Examples: penicllins, cephalosporins, bacitracin and Vancomycin.

Inhibitors of cell membrane function.

A disruption or damage to this structure could result in leakage of important solutes essential for the cell's survival. It can often be toxic for use in the mammalian host. Most clinical usage is therefore limited to topical applications. Examples: polymixin B and colistin.

Inhibitors of protein synthesis.

Enzymes and cellular structures are primarily made of proteins. Protein synthesis is an essential process necessary for the multiplication and survival of all bacterial cells. They lead to the death of the organism or the inhibition of its growth and multiplication. Examples: Aminoglycosides, macrolides, lincosamides, streptogramins, chloramphenicol, tetracyclines.

Inhibitors of nucleic acid synthesis.

DNA and RNA are keys to the replication of all living forms, including bacteria. Some antibiotics work by binding to components involved in the process of DNA or RNA synthesis, which causes interference of the normal cellular processes. Examples: quinolones, metronidazole, and rifampin.

Inhibitors of other metabolic processes.

Other antibiotics act on selected cellular processes essential for the survival of the bacterial pathogens. For example: sulfonamides and trimethoprim.

Answer 2

Inhibition of cell wall synthesis

disruption of cell membrane function

inhibition of protein synthesis

inhibition of nucleic acid synthesis

anti-metabolite actions