Tigecycline mode of action?

How does tigecycline work (its mode of action)?

Tigecycline is a glycylcycline antibiotic that works by binding to the bacterial ribosome and blocking protein synthesis. It reversibly binds to the 30S ribosomal subunit at the A site, which prevents transfer of aminoacyl-tRNA and stops translation during the formation of new proteins. This ribosomal blockade is the core of tigecycline’s antimicrobial effect.

What does tigecycline target inside the cell?

Because tigecycline inhibits translation at the ribosome, it targets an early step in bacterial growth rather than damaging cell walls or DNA directly. By preventing successful tRNA selection and peptide elongation, bacteria cannot produce essential proteins required for survival and replication.

Why is tigecycline classified as a glycylcycline (and how does that matter)?

Tigecycline is designed to overcome common tetracycline-related resistance mechanisms. Its glycylcycline structure allows it to retain ribosomal binding activity even when bacteria have tetracycline efflux pumps or ribosomal protection proteins that would reduce the effectiveness of older tetracyclines.

What does “ribosome inhibition” mean for resistance and clinical use?

When tigecycline’s main action is on the ribosome, resistance can arise from alterations that reduce drug binding at the ribosomal A site or mechanisms that protect/alter the ribosome. As a result, susceptibility can vary by organism and local resistance patterns, which influences whether tigecycline is used as an option for complicated bacterial infections.