Characterization of selected clinical isolates and antimicrobial properties of ethanol root extract of Anacardium occidentale L.

Abstract

Ethanolic root extract of Anacardium occidentale L. was evaluated for antimicrobial activities against selected clinical isolates. Bacteria and fungi pathogens obtained from the laboratory unit of a functional health facility for this study included Escherichia coli, Kblesiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Streptococcus sp., Candida albicans and Aspergillus niger. The identities of the bacteria spp. were re-established following standard physical and biochemical routines. Susceptibility screenings were performed to determine the zone of inhibition as well as minimum inhibitory concentration of the plant extract using well diffusion and broth dilution methods respectively. Significant, P< 0.05, dose-dependent antibacterial activities were recorded against all the bacterial isolates. However, no detectable activity was observed against either of the fungi species. Although the highest inhibition diameter, 12.2±0.2 mm, was obtained against Staphylococcus aureus, it was observed that E. coli and Streptococcus sp. were the most susceptible organisms based on lower minimum inhibitory and bactericidal concentrations of 62.50 mg/ml respectively. The extract demonstrated broad-spectrum, inhibitory and bactericidal potentials.