The most impoant mechanism by which tetracycline antibiotics exe antimicrobial action
TETRACYCLINES Mechanism of action:- The tetracyclines are primarily bacteriostatic; inhibit protein synthesis by binding to 30S ribosomes in susceptible organism. Subsequent to such binding, attachment of aminoacyl-t-RNA to the acceptor (A) site of mRNA-ribosome complex is interferred as a result, the peptide chain fails to grow. The sensitive organisms have an energy dependent active transpo process which concentrates tetracyclines intracellularly. In gram-negative bacteria tetracyclines diffuse through porin channels as well. Ref:- kd tripathi; pg num:-733
They interfere with DNA mediated RNA synthesis in bacteria
They bind to 50S ribosomes and interfere with translocation of the growing peptide chain in the bacteria
They bind to 30S ribosomes and inhibit bacterial protein synthesis
They chelate Ca2+ ions and alter permeability of bacterial cell membrane
Antibiotics