Evaluation of antimicrobial activity of plant extracts on antibiotic- susceptible and resistant Staphylococcus aureus strains

Ethanolic leaf extracts of 5 medicinal plants traditionally used in medicine were studied for their antimicrobial activity against antibiotic-susceptible and resistant Staphylococcus aureus strains isolated from different clinical samples. The antimicrobial activity of plant extracts was determined by using agar well diffusion method. The plant extracts showed varied levels of antimicrobial activity against antibiotic-sensitive and resistant S. aureus isolates. Extracts of Syzygium cumini (Jamun) and Lawsonia inermis (Mehndi) showed good activity against most of the sensitive and resistant isolates whereas the extracts of Ficus religiosa (Peepal), Ocimum sanctum (Tulsi) and Zizyphus mauritiana (Ber) showed moderate activity against most of the sensitive and resistant isolates. The plant extracts showed variable initial MIC values against resistant and sensitive S. aureus isolates being minimum for S. cumini (1.2 mg/ml, 0.6 mg/ml) and L. inermis (0.6 mg/ml, 1.2 mg/ml). The final MIC and MBC values were observed to be either same or 2 to 4 fold higher than initial MIC. The present study thus suggests the use of these medicinal plants in the treatment of various diseases caused by drug resistant S. aureus