Inhibition of ATCC bacteria strains by commercial antibiotics, in percentage ± SEM.

Each well received 90 μl of antibiotic solutions plus 90 μl of broth. In each well 20 μl of bacterial suspension was added, resulting in a final volume of 200 μl at the concentration of 105 CFU/ml. The plates were incubated (37°C, 18 h) and turbidity was measured at 595 nm to assess bacterial growth. The results were expressed as inhibition percentage of optical density (OD) against a control in the absence of the control antibiotics. Three independent experiments were performed in triplicate.