Methicillin Resistant Staphylococcus Aureus (MRSA) has gained much attention in the last decade, as the MRSA is a major cause of hospital acquired (nosoconical infections). β-lactam antibiotics are the preferred drugs against S. aureus infections, although S. aureus has developed resistance to the β-lactam antibiotics due to the production of chromosomal or plasmid mediated β-lactamases or by producing Pencillin Binding Proteins (PBPs). The Extended Spectrum β-Lactamase (ESBL) producers are highly resistant to several conventional antibiotics. This limits therapeutic options. Hence efforts are now taken to screen few medicinal plants, which are both economic and less toxic, against the ESBL producers. Among the several plants screened, we have chosen to screen the alcohol extracts of a traditional medicinal plant, Elephantopus scaber (Asteraceae) against several clinical strains of ESBL producing MRSA. ESBL producers were screened by double disc synergy test. Methanol, hexane and acetone extracts of Elephantopus scaber were investigated for their ability to inhibit the growth of the chosen ESBL producing multidrug-resistant bacteria by the disc diffusion method. Minimal Inhibitory Concentrations (MICs) were determined by micro broth dilution method. Synergistic interaction of plant extracts with certain antibiotics was also evaluated. On the basis of promising activity, acetone extracts were fractionated and their phytochemical analysis showed the presence of terpenoids, proteins and traces of steroids. TLC bioautography of the fraction showed the active compound to be terpenoids. The strong in vitroantibacterial activity of terpenoid derivatives against ES βL-producing MRSA bacteria suggests the compounds might find wide pharmaceutical use. Further investigations to elucidate the active compound are required.
R. Jasmine, P. Daisy and B.N. Selvakumar, 2007. Evaluating the Antibacterial Activity of Elephantopus scaber Extracts on Clinical Isolates of β-lactamase Producing Methicillin Resistant Staphylococcus aureus from UTI Patients. International Journal of Pharmacology, 3: 165-169.