Zeb Saddiqe, Ismat Naeem, Abdul Hannan, Yasir Cheema
The present study was carried out to evaluate the antimicrobial properties of extracts of aerial parts of Hypericum ericoides, against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). The extracts were screened for anti-MRSA activity using agar well-diffusion method for preliminary screening against a reference ATCC strain and agar dilution method against thirty clinical isolates for the determination of minimum inhibitory concentration (MIC). All the extracts were also subjected to phytochemical analysis. In agar diffusion method n-hexane fraction was the most active with diameter of zone of inhibition 12 mm at 1.875 mg/ml. The inhibitory effect was dose dependant with larger zones of inhibition observed at higher concentration. No activity was shown by ethyl acetate fraction. In agar dilution method significant antibacterial activity was observed for the crude methanolic extract and n-hexane and dichloromethane fractions with MIC values 2048, 1024 and 512 μg mL-1 respectively. The study concluded that the n-hexane and dichloromethane fractions of H. ericoides have significant antibacterial potential against MRSA strains and can be a good source of isolating antibiotics with potential activity against multi drug-resistant bacterial strains.