Evaluation of antibacterial activity of belizean plants: an improved method

The influences of medium type, inoculum density, and a cold incubation on antimicrobial assay sensitivity were tested. The largest and most distinct zones were produced using nutrient agar and the 1/10 4 inoculum density for Staphylococcus aureus and Proteus mirabilis but a 1/10 12 inoculum density for Pseudomonas aeruginosa and Escherichia coli . The greatest number of zones were detected without cold incubation. Using this method, eight plants from Belize were screened for antibacterial activity. Six plants showed activity against the four organisms tested. Both inoculum density and medium type played important roles in assay sensitivity; however, inoculum density was of more practical significance.