Anti-MRSA Activity of Padina tetrastromatica, Padina gymnospora from Gulf of Mannar Biosphere

Nowadays coming out of bacterial resistance poses a significant clinical problem. Hence, the aim of this study was to explain the current susceptibility patterns of methicillin-resistant Staphylococcus aureus (MRSA).As well as to find out antimicrobial characteristics in the different organic solvents with increasing polarity viz., hexane, chloroform, ethyl acetate, and methanol extracts of Padina tetrastromatica, Padina gymnospora marine macro algae belonging to the family Phaeophyta were studied. Their crude extracts were tested against Staphylococcus aureus (MTCC 737 & 7443), and three clinical isolates of MRSA were tested and has been shown to exhibit antibacterial activity against methicillin methicillin-resistant Staphylococcus aureus (MRSA). The Minimum inhibitory concentrations (MIC) and Minimum Bactericidal Concentrations (MBC) were determined. The ethyl acetate extracts of the seaweeds showed the presence of Photochemical, terpenoids, tannins, phenolic compounds and steroids strongly than the other solvent extracts. The highest activity was recorded in the ethyl acetate extract of Padina tetrastromatica than the other extract tested. The mean zone of inhibition produced by the extracts in disc diffusion assays against the tested bacterial strains ranged from 7.1 to 26.5 mm. The lowest MIC (62.5 µg/ml) and MBC (125 µg/ml) values were observed in the ethyl acetate extract of P. tetrastromatica against S. aureus (737 & 7443), MRSA1 and MRSA3. Further separation of active principle from the potential seaweed extract as a source of antibacterial compound useful for the control of Methicillin resistant S. aureus is under progress.