PetriKey

Antimicrobial

Glycylcyclines (tigecycline)

Tetracycline derivative evading tet resistance

gly-sil-SY-kleens

protein-synthesis30stetracycline-derivativebroad-spectrumamr

High-yield clue

Tigecycline binds the 30S ribosome more tightly than tetracyclines, so it overcomes tet efflux pumps and ribosomal protection.

Overview

A tetracycline-derived protein-synthesis class represented by tigecycline, studied for a bulky D-9 side chain that lets it evade classic tetracycline resistance mechanisms.

Classification

  • Protein-synthesis inhibitor
  • Binds 30S ribosomal subunit
  • Bacteriostatic
  • Broad Gram-positive/Gram-negative/anaerobe spectrum

Lab & identification clues

  • Evades TetB efflux pump vocabulary
  • Overcomes ribosomal protection (tetM/tetO) concept
  • Limited activity against Pseudomonas and Proteus

Associations

  • Multidrug-resistant organism reserve vocabulary
  • Low serum concentrations (tissue distribution) concept
  • Derived from minocycline scaffold

Commonly confused with

  • Tetracyclines
  • Chloramphenicol

Your notes

Original mechanism summary for microbiology study. Sources checked: CDC antimicrobial-resistance guidance, NCBI Bookshelf Medical Microbiology, and standard coursework frameworks; reviewed 2026-06. Covers class, mechanism, and resistance vocabulary only; no prescribing, dosing, or patient-specific treatment guidance.

CDC: CDC antimicrobial resistance overview and threat reportssourceWHO: WHO bacterial priority pathogens list 2024sourceNCBI Bookshelf: Medical Microbiology antimicrobial mechanism foundationssource