2.6. Antibacterial screening

The antimicrobial activity of medicinal plants extracted with solvent and water was determined according to National Committee for Clinical Laboratory Standards by disc diffusion method (NCCLS, 1993, Rajkumari et al., 2019). The inoculum concentration was determined as 10⁶ cfu/ml and it was spread on Meuller Hinton Agar plates with the use of sterile swab dipped with selected bacterial suspension. Then, 6 mm disc was made and loaded with 25 µl plant extract (20 µg/ml) and it was allowed to diffuse at 2–8 °C for 4 h and incubated for 24 h at 37 °C. Antibiotic standard (10 μg) was used as the positive control. After 24 h, the zone of inhibition (mm) was measured. Three different experiments were performed and the results (zone of inhibition) were expressed as mean ± standard deviation.