Study of Antimicrobial activity of selected Iranian plant extracts on vancomycin resistant Staphylococcus epidermidis

Staphylococcus epidermidis is one the common bacteria causing infections in humans. Its increasing resistance has led to growing use of antibiotic and introduction of new medicines into the market. Strains of Staphylococcus epidermidis are or becoming resistant to many antibiotics, including vancomycin. Since the resistance of the bacteria to vancomycin is increasing, it is important to replace vancomycin with alternative medicines. This study explores antibacterial effects of hydroalcoholic extracts of selected Iranian medicinal plants on clinical vancomycin-resistant strains of Staphylococcus epidermidis. Hydroalcoholic extracts of plant organs with reported experimental antimicrobial effects , Lagenaria vulgaris, Punica grantum, Allium ascalonicum, Persian Marjoram, Urtical duicia, Chicorium intybus, Rubia tinctorum, Trigonella foenum, Descurainia sophia, and Pistaca vera were examined using disk diffusion and dilution antimicrobial susceptibility tests in liquid medium to determine the minimum inhibitory concentration of 15 strains of vancomycin-resistant Staphylococcus epidermidis. The highest and lowest minimum inhibitory concentration were found for the extracts of Allium ascalonicum (MIC 50 128g/ml) and Lagenaria vulgaris (MIC 50 1000 g/ml), respectively. Since a growing resistance to vancomycin is observed in Staphylococcus epidermidis, our findings may be important because of the considerable effect of Allium ascalonicum extract on isolated vancomycin-resistant Staphylococcus epidermidis. Further research is required into the clinical applications of extracts.