Antimicrobial Properties of Ethanol Leaf Extract of Millettia aboensis on Some Selected Clinical Isolates

Abstract

There is renewed interest in the search for plants with anti-microbial activity leading to various plants being investigated for their potential efficacy. Ethanol leaf extract of Millettia aboensis and reference drug (commercial Geniclox 500) were tested in vitro against four clinical isolates, namely, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus for antibacterial activity. The ethanol leaf extract of M. aboensis inhibited the growth of K. pneumoniae, P. aeruginosa, and S. aureus but did not inhibit the growth of E. coli while the reference drug inhibited the growth of all the isolates. The Minimum inhibitory concentration (MIC) against susceptible organisms for the ethanol extracts was 12.5mg/ml for K. pneumoniae and P. aeruginosa and 50 mg/ml for S. aureus. The MIC of the reference antibiotics was 12.5 mg/ml for E. coli, P. aeruginosa and K. pneumoniae and a higher concentration of the reference antibiotics (200 mg/ml) was needed to inhibit S. aureus when compared to E. coli, K. pneumoniae and P. aeruginosa. The equivalent-point inhibitory kinetic (I keq) for both the reference drug and solvent extract of Millettia aboensis against P. aeruginosa and K. pneumoniae were 125 and 83.33 mg/ml respectively. There is need to harness the efficacious potentials of plants in view of isolating and identification of active principles present in plant extracts which could possibly be exploited for pharmaceutical use.