Michael Ndikau¹, Naumih Noah^2*, Dickson Andala³ & Eric Masika^1
1Department of Chemistry, Kenyatta University, P.O Box 43844-00100, Nairobi-Kenya
²School of Pharmacy and Health Sciences, United States International University-Africa, P.O Box 14634-00800, Nairobi-Kenya
³Department of Chemistry, Multimedia University of Kenya, P.O Box 15653-00503, Nairobi-Kenya

Abstract
The increased resistance of microbes to current antibiotics calls for development of new effective antimicrobial agents. Metal nanoparticles such as silver nanoparticles have continued to attract increased research interest in the recent past because of their wide range of applications such as in the areas of chemical sensing, nanomedicine and electronics. In this work, spherical AgNPs (17.96 ± 0.16 nm in diameter) synthesized via a green method using Citrullus lanatus (water melon) fruit rind extract were evaluated for antimicrobial activity against clinical isolates of Escherichia coli (E.coli) and Salmonella typhi (S.typhi) bacteria using the disc-diffusion method. The Minimum Inhibition Concentration (MIC) value of the nanoparticles was found to be 45.00 ± 0.01 g/ml for S.typhi and 38.50 ± 0.00 g/ml for E.coli while the Minimum Bactericidal Concentration (MBC) value was found to be 60.00 ± 0.05 g/ml for S.typhi and 50.00 ± 0.00 g/ml for E.coli. This study demonstrated that these two bacterial strains were susceptible to the green synthesized AgNPs.

Keywords:

Green synthesis; Antimicrobial activity; Silver nanoparticles; Citrullus lanatus.

Ndikau et al. JKCS 13-1 (2020) 22-27