Teicoplanin: Class and Mechanism of Action
Teicoplanin is a glycopeptide antibiotic that inhibits bacterial cell wall biosynthesis by binding to the D-alanyl-D-alanine terminus of peptidoglycan precursors, preventing cross-linking and cell wall assembly. 1, 2, 3
Antibiotic Class
- Teicoplanin belongs to the glycopeptide class of antibiotics, structurally related to vancomycin but with distinct chemical properties 1, 2
- It is a fermentation product of Actinoplanes teicomyceticus, isolated in the mid-1970s 2
- The molecule consists of six fatty-acid components attached to a common aglycone, making it 50 to 100 times more lipophilic than vancomycin 2
Mechanism of Action
- Teicoplanin achieves its bactericidal effect by binding to acyl-D-alanyl-D-alanine residues in the bacterial cell wall, the same target as vancomycin 3, 4
- This binding physically blocks the transglycosylation and transpeptidation reactions necessary for peptidoglycan synthesis 2, 3
- By preventing cell wall cross-linking, teicoplanin causes bacterial cell lysis and death in a concentration-dependent manner 5
Antimicrobial Spectrum
- Activity is restricted exclusively to Gram-positive aerobic and anaerobic bacteria; teicoplanin has no activity against Gram-negative organisms 6, 3, 7
- The spectrum includes staphylococci (including methicillin-resistant Staphylococcus aureus [MRSA]), streptococci, corynebacterium, listeria, and anaerobic cocci 2, 3
- Teicoplanin is generally more active than vancomycin against streptococci and Gram-positive anaerobes, exhibits similar activity against S. aureus, but vancomycin may be more active against some coagulase-negative staphylococci strains 3, 7
Clinical Context and Resistance Considerations
- Teicoplanin became a first-choice antibiotic for severe hospital-acquired Gram-positive infections, particularly due to the pandemic of MRSA 1
- The Centers for Disease Control and Prevention emphasizes judicious use to prevent emergence of resistant organisms like vancomycin-resistant enterococci (VRE) 6
- Resistance to teicoplanin is difficult to induce under laboratory conditions, though it has been reported with coagulase-negative staphylococci 2, 3
- Cross-resistance between teicoplanin and vancomycin can occur through various mechanisms, particularly among enterococci and S. aureus 5
Important Caveats
- When broad-spectrum coverage is needed, teicoplanin must be combined with other antimicrobials since it lacks Gram-negative activity 6
- Inoculum size and culture media composition can influence teicoplanin's in vitro activity, particularly against coagulase-negative staphylococci 3
- The drug's high lipophilicity (50-100 times greater than vancomycin) affects its tissue distribution and allows for intramuscular administration 2, 7