Final answer:
Pseudomonic acid inhibits protein synthesis by binding to isoleucyl-tRNA synthetase, with resistance arising from modifications to the target enzyme. General drug resistance mechanisms include enzymatic degradation and modification, which are countered by compounds like clavulanic acid.
Step-by-step explanation:
The mechanism of action of pseudomonic acid, which is a type of antibiotic, involves the inhibition of protein synthesis in bacteria by irreversibly binding to isoleucyl-tRNA synthetase. This prevents the incorporation of isoleucine into protein chains, thereby halting bacterial growth. Resistance to pseudomonic acid can be created when bacteria acquire mutations that alter the target enzyme, lower the affinity of the drug, or when they produce an alternate enzyme that bypasses the drug's effect.
One of the general mechanisms of drug resistance includes drug modification or inactivation. This can happen when resistance genes code for enzymes that chemically modify an antimicrobial, either by inactivation or by enzymatic degradation. For example, resistance to ß-lactams involves the production of ß-lactamases that break the ß-lactam bond within the drug, negating its antibacterial effect. Similarly, aminoglycoside resistance can occur through modifications that impair drug binding to its target. Moreover, drugs like clavulanic acid have been developed to counteract resistance by inhibiting ß-lactamases.