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In vitro activity of GAR-936 against vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus

R Patel1, M S Rouse, K E Piper

  • 1Division of Infectious Diseases and Infectious Diseases Research Laboratory, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA. patel.robin@mayo.edu

Diagnostic Microbiology and Infectious Disease
|December 8, 2000
PubMed

Insights

The novel glycylcycline antimicrobial GAR-936 effectively inhibits resistant bacteria, including vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus. This new agent shows potent activity against challenging clinical isolates.

Area of Science:

  • Microbiology
  • Pharmacology
  • Infectious Diseases

Background:

  • Emergence of antimicrobial resistance poses a significant global health threat.
  • Vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and penicillin-resistant Streptococcus pneumoniae are key multidrug-resistant pathogens.
  • Novel antimicrobial agents are urgently needed to combat these resistant infections.

Purpose of the Study:

  • To evaluate the in vitro antimicrobial activity of the new glycylcycline agent GAR-936.
  • To assess GAR-936 activity against a panel of clinically relevant resistant bacterial isolates.
  • To investigate potential synergistic or antagonistic interactions between GAR-936 and quinupristin/dalfopristin.

Main Methods:

  • Antimicrobial susceptibility testing (MIC determination) was performed on clinical isolates.
  • Isolates included VRE (vanA, vanB, vanC-1, vanC-2/3 genes), MRSA, and high-level penicillin-resistant S. pneumoniae.
  • Time-kill experiments were conducted to assess drug interactions.

Main Results:

  • GAR-936 demonstrated potent activity against all tested isolates.
  • Minimum inhibitory concentrations (MICs) were ≤1 µg/ml for VRE, ≤2 µg/ml for MRSA, and ≤0.25 µg/ml for resistant S. pneumoniae.
  • Time-kill studies showed no synergy or antagonism between GAR-936 and quinupristin/dalfopristin against VRE.

Conclusions:

  • GAR-936 exhibits broad-spectrum activity against important multidrug-resistant Gram-positive bacteria.
  • The glycylcycline agent GAR-936 represents a promising therapeutic option for infections caused by VRE, MRSA, and resistant S. pneumoniae.
  • GAR-936 does not appear to interact synergistically or antagonistically with quinupristin/dalfopristin in vitro.

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