Sub-minimum inhibitory concentrations of Zinc Oxide Nanoparticles Reduce the Expression of the Staphylococcus aureus Alpha-Hemolysin
1Tehran Payam Noor University, East Tehran Branch, 2Faculty Member in Payam Noor University, Tehran, 3Member of Faculty of Microbiology, Gorgan Faculty of Medical Sciences, 4Instructor, Microbiology Department of Gorgan Faculty of Medical Sciences, 5Medical Laboratory Research Center,Golestan University of Medical Sciences, Gorgan, Iran.
Professor, Medical Laboratory Research Center, Golestan University of Medical Sciences, Gorgan, Iran. Email: [email protected]
In this study, the effect of sub-MIC concentrations of the ZnO nanoparticle on the expression of the alpha-hemolysin gene as a significant virulence factor of Staphylococcus aureus is assessed. The effect of sub-MIC concentration (312.5 μg/ml) of the ZnO nanoparticle on the hemolysis phenomenon was studied phenotypically on Blood agar media with and without ZnO nanoparticles and genetically by Real Time PCR method in media containing and without ZnO. The hemolysis phenomena of all S.aureus isolates in a blood agar with a sub-MIC concentration and 1/2, 1/4, and 1/8 MIC concentrations of ZnO nanoparticles was completely restrained. After performing Real Time PCR, the amount of hla gene expression in 12 h culture in media with 1/2 and 1/4 MIC concentration of ZnO nanoparticles was reduced, but gene expression in the 1/8 MIC concentration was did not decrease. Hemolysis by S. aureus was decreased in the presence sub-MIC concentration of ZnO nanoparticles. The use of ZnO nanoparticle in sub-MIC concentration as cover of artificial instruments such as catheter, intravascular catheters or shunts to control bacterial infection is suggested for further study.