Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul (Sep 2012)
Effect of Zinc Oxide (ZnO) Nanoparticles on Death Kinetic of Gram-Negative and Positive Bacterium
Abstract
BACKGROUND AND OBJECTIVE: Hospital acquired infections are a major problem worldwide and controlling the spread of bacteria within a hospital is a constant challenge so this study was done to survey the effect of ZnO nanoparticles suspension on death kinetic of gram negative and gram bacteria in vitro.METHODS: In this experimental study, suspension has been prepared from commercial ZnO nanoparticles in broth medium. After preparing standard strains E. coli ATCC 25922 and P. aeruginosa ATCC 27853 as gram-negative bacteria and S. epidermidis PTCC 1114 and S. aureus ATCC 25923 as gram-positive bacteria, death kinetic study have been evaluated with 1 and 2 times of Minimum Inhibitory Concentration (MIC), and death kinetic study evaluated (at zero to 360 minute of treatment time) using first-order reaction kinetic with 0.5 McFarland standard bacterial suspension (108 cfu/ml).FINDINGS: Effect of ZnO suspension on death kinetic of bacteria showed the survival ratio of bacteria decreased with increasing ZnO concentration. With drawing logarithmic survival ratio and treatment time as ordinate and abscissa, respectively, the population of all strains decreased almost linearly. The apparent death rate constant (k) was found to increase with increasing time and ZnO concentration from 1xMIC to 2xMIC. CONCLUSION: Base on the results, E. coli population at the treatment time decrease faster than others. Also, the results showed that ZnO could be a highly effective disinfect for controlling of gram negative bacteria especially E. coli.
