Minimum inhibitory concentration (MIC) determination of herbal extracts against Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus

Abstract

The objective of this study was to determine the minimum inhibitoryconcentration (MIC) of crude extract from five medical herbs in Vietnam (Camellia sinensis, Eclipta prostrata L., Pseuderanthemum palatiferum, Psidium guajava, Azadirachta indica) against Escherichia coli ATCC25922, Salmonella Typhimurium, Staphylococcus aureus ATCC25923 by macro - dilution method. These results were the basis for the application of these herbs in the prevention and treatment of diseases in animals. The results showed that MICs of Camellia sinensis against E. coli, S. Typhimurium, and S. aureus were 8 - 16 mg/mL, 8 - 16 mg/mL, 0.5 mg/mL respectively; MICs of Eclipta prostrata L. against E. coli, S. Typhimurium, and S. aureus were 16 mg/mL, 16 mg/mL, 1 - 2 mg/mL respectively; MICs of Pseuderanthemum palatiferum against E. coli, S. Typhimurium and S. aureus were 8 mg/mL, 4 - 8 mg/mL, 2 - 4 mg/mL respectively; MICs of Psidium guajava against E. coli, S. Typhimurium and S. aureus were 16 mg/mL, 16 mg/mL, 0.125 - 0.25 mg/mL respectively and MICs of Azadirachta indica against E. coli, S. Typhimurium and S. aureus were more than 16 mg/mL.