ABSTRACT
Garlic has been known as an important medicinal plant for centuries and belonging to the Liliaceae family. Cardamom is the dried fruit of the tall perennial herbaceous plant, Elettaria cardamomum Maton, and belonging to the Zingiberaceae. family. The purpose of this study was to investigate the effect of aqueous extract of garlic and methanolic extract of cardamom on MRSA and P. aeruginosa. Dry garlic bulbs [l00g] were peeled and homogenized distilled water [1:1 w/v], using a blender and 50% juice of garlic is obtained, centrifuged and then the supernatant of garlic juice is collected and passed through a 0.45 micro m filter and stored at 4 for further experiments. Also after collecting cardamom seeds, drying and making it powder, extracts were obtained by using percolation method with methanol. for evaluating the antibacterial activity of the extracts or garlic and cardamom, the microbial suspension was prepared by direct colony suspension method and different dilutions of extracts [1:2, 1:4, 1:8,. .., 1:64 v/v for garlic; 800, 650, 400,. .., 50 micro g/ml for cardamom] were prepared and tested against of MRSA ATCC 33591 and P. aeruginosa ATCC 27853. Minimum Inhibition Concentration [MIC] was obtained via Disc diffusion and Broth dilution and well diffusion method. We also analyzed morphological changes of MRSA and P.aeruginosa by light microscopy [LM] and biochemical properties was studied by inoculation of low concentrations of garlic and cardamom extracts to bacterial culture. The results showed that cardamom extract has no effect against Pseudomonas aeruginosa but garlic extract is effective on P. aeruginosa. Garlic extract [1:2, 1:4, 1:8, 1:16, containing 220, 110, 55, 27.50 micro g/ml allicin] inhibited the growth of MRSA and concentrations of 1:2 to 1:8 [v/v] inhibited the growth of Pseudomonas aeruginosa. Further more MRSA is sensitive to cardamom extract in 800 to 200 micro g/ml. In general, the minimal inhibitory concentration for MRSA [garlic MIC 1:16; allicin mean MIC 7.50 micro g/ml] were lower than for P. aeruginosa [garlic MIC 1:8; allicin mean MIC 55 micro g/ml].The treatment group with garlic extract showed a changed form of morphology such as cellular swelling, partially distored shape and changes in the size of bacteria, but cardamom extract dose not reveal any changes compared to the control. It was also observed in low concentrations of garlic, production of catalase enzyme and pyocyanine pigment by P.aeruginosa were decreased but it increased strain hemolysis ability, and acid production from saccharose, manitol by MRSA changed to negative. This research showed that garlic and cardamom extracts have different antibacterial properties against 2 tested bacteria