In vitro drug interactions of gallates with antibiotics in Staphylococcus Aureus

Front Biosci (Elite Ed). 2010 Jan 1;2:668-72. doi: 10.2741/e126.


The antimicrobial activities of tetracycline, mupirocin, and fusidic acid are tested in combination with Epicatechin Gallate (ECG), and Ethyl Gallate (EG) using 2 Methicillin resistant (MRSA) and 2 Methicillin sensitive (MSSA) strains of Staphylococcus aureus. Sub-inhibitory concentration of EG at 256 mg l-1 is found to be synergistic when used in combination with tetracycline, mupirocin, and fusidic acid; and a sub-inhibitory concentration of ECG at 32 mg l-1 is found to be synergistic with tetracycline in all the four Staphylococcus aureus strains tested. The synergistic combinations reduce the MICs of all the above three antibiotics by 4 fold. Combining ECG at 32 mg l-1 with mupirocin, reduces the MIC of mupirocin by four fold in MSSA C1 strain. 74 per cent of the combinations show consistent results in both time-kill assay and checkerboard method. The identified combinations may lead towards novel therapeutic interventions for treating MRSA infections.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Catechin / analogs & derivatives*
  • Catechin / pharmacology
  • Drug Interactions / physiology*
  • Fusidic Acid
  • Gallic Acid / analogs & derivatives*
  • Gallic Acid / pharmacology
  • In Vitro Techniques
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / metabolism*
  • Microbial Sensitivity Tests
  • Mupirocin
  • Tetracycline


  • Anti-Bacterial Agents
  • ethyl gallate
  • Fusidic Acid
  • Gallic Acid
  • Catechin
  • epicatechin gallate
  • Mupirocin
  • Tetracycline