In vitro drug interactions of gallates with antibiotics in Staphylococcus Aureus

• Published in: Frontiers in bioscience (Elite edition) Vol. 2; no. 2; p. 668
• Main Authors: Soe, Win Mar, Tzer Pin Lin, Raymond, Chu Sing Lim, Lim, Sakharkar, Kishore R, Sakharkar, Meena K
• Format: Journal Article
• Language: English
• Published: Singapore 01.01.2010
• Subjects: 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

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.