Potentiation of the in vitro antistaphylococcal effect of oxacillin and tetracycline by the anti-inflammatory drug diacetyl rhein.
Keywords
Abstract
BACKGROUND
The anti-inflammatory drug diacetyl rhein has been found to possess promising antistaphylococcal effects against various drug-resistant strains in our previous study. In the present work, we explored the in vitro combinatory interactions of diacetyl rhein with oxacillin and tetracycline against 13 standard strains and clinical isolates of Staphylococcus aureus, including those resistant to erythromycin, methicillin and tetracycline.
METHODS
Minimum inhibitory concentrations were determined by broth microdilution assay, and the effects of combinations were evaluated according to the sum of fractional inhibitory concentrations (ΣFICs).
RESULTS
Synergistic or additive effects were observed against all S. aureus strains (ΣFIC 0.258-1), whereas diacetyl rhein-oxacillin appeared to be the most effective combination, synergistically inhibiting the growth of 4 strains tested.
CONCLUSIONS
To our best knowledge, this is the first report on a synergistic antibacterial effect of diacetyl rhein. Our results suggest this promising compound for further evaluation of its synergistic anti-infective potential as an agent with a combined anti-inflammatory and synergistic antibacterial action.
