The goal of this study was to evaluate the comparative effect of Securinega virosa plant extract and partitioned fractions on Methicillin-resistant Staphylococcus aureus (MRSA). S. virosa Leaves were extracted with 80% methanol. Phytochemical screening of the extract was performed using standard analytical methods. The antimicrobial activity of the crude extract and partitioned fractions were evaluated by the agar well diffusion method against the strain of MRSA. Also, the minimum inhibitory concentration of crude extract and partitioned fractions were evaluated. Phytochemical screening of the Securinega virosa extract (leaf) showed the presence of alkaloids, flavonoids, saponin, steroids, tannins, terpenes, cardiac glycosides, anthraquinones, and reducing sugars. Antibacterial evaluation of crude extract of S. virosa at concentrations of 100, 50, 25, 12.5, and 6.25 mg/ml with a mean zone of inhibition of 14.67 +/- 0.82, 10.33 +/- 0.82, 8.33 +/- 0.41, 6.67 +/- 0.41, and 4.33 +/- 0.82 mm, respectively. While those of aqueous and chloroform fractions showed inhibition zone of 10.50 +/- 0.35, 6.67 +/- 1.47, 4.67 +/- 0.82, 1.67 +/- 2.04, and 1.33 +/- 1.63 mm for aqueous fraction and 10.33 +/- 1.08, 6.67 +/- 0.41, 4.33 +/- 1.08, and 2.66 +/- 1.78 mm, respectively for chloroform fraction. The antimicrobial evaluation expressed as the minimum inhibitory concentration of crude extract showed minimum activity at 25 mg/ml for crude extract and 50 mg/ml for aqueous and chloroform fractions respectively. The various extracts of Securinega virosa (aqueous, chloroform, and crude methanol) were found to possess antibacterial activity on isolated Methicillin-resistant Staphylococcus aureus at varying concentrations, and the crude extract possessed higher activity than the other two extracts.
