A study on antibacterial effect of grape seed extracts in common clinical and drug resistant isolates

Abstract

Background: Grape seeds are proposed to have antimicrobial activity, antioxidant effect and various other benefits to mankind. A study was done to assess the antibacterial effect of grape seed extract against common clinical isolates and drug resistant pathogenic strains.Methods: Grape seed extract prepared was investigated for its antibacterial effect against 65 bacterial isolates obtained from clinical specimens by agar well diffusion assay and the results were compared with routinely used antibiotics namely, Gentamicin for the common clinical isolates, Vancomycin for MRSA strains and Amikacin for ESBL organisms respectively.Results: Grape seed extract produced moderate zone of inhibition ranging between 11-15 mm among the 35 test common clinical isolates namely Staphylococcus aureus, Escherichia coli, Klebsiella sp and Pseudomonas aeruginosa. E.coli showed the highest susceptibility with zone ranging from 12-14 mm with increasing concentration of the extract starting from2 mg/ml to the highest being 20 mg/ml. Among the 30 drug resistant pathogenic strains like MRSA and ESBL producing organisms, the grape seed extract was found to be effective against 3 out of the 10 of MRSA and 2 out of the 10 of ESBL-E.coli at the highest concentration of 20 mg/ml. However, ESBL producing Klebsiella species were found to be resistant even to the highest concentration of the extract. Conclusions: The results provide evidence that the grape seed extract could be a potential antibacterial agent and this effect can further be made evident with improved methodologies.