Evaluation of bactericidal and bacteriostatic potentials of leaves and stem bark of Diospyros mespiliformis against clinical and foodborne bacterial pathogens

The importance of medicinal plants has remarkably increased in which some are distinguished by their natural products that help them resist the recalcitrant bacterial strains.This study aimed to determine antibacterial activity of Diospyros mespiliformis leaves and stem bark extracts against clinical (Staphylococcus aureus and Klebsiella spp.) and foodborne (Salmonella typhi and Escherichia coli) pathogens. Methanol and aqueous extracts of D. mespiliformis leaves and stem bark were subjected to antimicrobial susceptibility testing using disc diffusion test. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations were determined by broth dilution test. All the clinical and foodborne pathogens were inhibited after treatment with extract in disk diffusion test with range 6.00 -16.00 mm although there was total resistance (0.00 mm) by Klebsiella spp. to the 10.00 mg/mL concentration of the stem bark methanol and aqueous extracts. The range of MIC values was between 1.25 mg/mL and 5.0 mg/mL while that of minimum bactericidal concentrations was between 2.5 mg/mL and 5.0 mg/mL, also with resistance to the highest concentration of 5.0 mg/mL by Klebsiella spp. In conclusion, the D. mespiliformis extracts exhibited antimicrobial activitiesand thus could be developed as antibiotics and as natural sanitizersfor washing raw food materials.