F. Rubab, M.F. Chaudhary, N.M. Butt
Preston University, Islamabad Campus, Pakistan
pp. 344 - 348
Keywords: zinc oxide nanoparticles, antibacterial effect, antibiotic resistant
We have investigated antibacterial properties of zinc oxide nanoparticles against gram negative bacteria isolated from drinking water. We isolated and identified Escherichia coli, Serratia marcescens, Enterobacter cloacae and Aeromonas hydrophila. Our results showed zinc oxide nanoparticles (Sigma Aldrich, USA) of 35nm size have significant antibacterial effect. Cell cultures were affected by ZnO nanoparticles at all tested concentrations (0, 100, 200, 300 & 500 µg/ml). Most significantly growth of E.coli was inhibited by nanoparticles at 500 µg/ml concentration, showing 28 mm diameter of zone of inhibition. Zones of inhibition for E. cloacae, S. marcescens and A. hydrophila were 24, 22 & 19 mm respectively . Highest zone of inhibition i.e. 25 mm was observed at 60 µl against E.coli. The E.cloacae, S.marcescens & A.hydrophila showed diameter of zones of inhibition of 19, 24 and 15 mm respectively . Among antibiotics tested, E. cloacae was found resistant against Erythromycin showing zone of inhibition of only 7 mm but same bacteria was sensitive to ZnO NPs showing zone of inhibition of 24 mm. ZnO NPs showed potential for effective antibacterial agent for bacteria including antibiotic resistant bacteria and eventually for water purification.