Antimicrobial Activity of Costus Plant Extract Against Methicillin-Resistant Staphylococcus aureus (MRSA, I3)

In the present investigation, a trial was carried out to find biological active agents isolated from Costus speciosus to control the resistance that pathogenic microorganisms build against antibiotics. The rhizomes of two costus varieties viz. Qust Hindi and Qust Bahri were carried out. Costus speciosus were dried, grinded and extracted with methanol and water. The extracts were tested for their antimicrobial activities against MRSA, I3, E. coli, I5 and Candida albicans isolated from King Fahd Hospital, Al Madinah Al Munawarah, KSA. The aqueous extract of Qust Hindi was more effective compared with methanolic extract and aquous extract of Qust Bahri against MRSA, I3 & E. coli, I5. Candida albicans was resistant to all plant extracts. Some parameters controlling the activity of this aqueous extract had been studied against pathogenic microorganisms under study. The highest antimicrobial activity obtained at the following conditions 121C, pH 5, shaking at light conditions, 200 rpm (48 h), lactose (1 %), non of nitrogen sources, cysteine, non of metallic ions, ascorbic acid (100ppm). Treatment of coleoptiles sections with crude Costus speciosus extract exhibited 20 % of straight growth of Hordeum vulgaris coleoptiles. Among all the tested solvent systems, ethyl acetate was found the best solvent for extraction of the antimicrobial substance. Fractions 3, 4, 5, 6, 7, 8 & 9 obtained from column chromatography exhibited the highest antimicrobial activity against MRSA, I3. TLC plates showed only two colored fractions, fraction I showed pale yellow under normal lab light, and pale fluorescent turquoise color under long wave length, and fraction II gave dark yellow under both normal and long wave length. Fraction I and fraction II gave antimicrobial activity of 25.5 and 16.25mm, respectively against MRSA, I3.