Anti-biofilm Effects of Zinc Oxide Nanoparticles Synthesized by Leaf Extract of Typha Latifolia on Biofilm Gene Expression in Multidrug-Resistant Klebsiella Pneumoniae Strains: A Laboratory Study

Background and Objectives: Biofilms are a community of bacteria on surfaces coated with extracellular polymeric materials, and one strategy to remove biofilms is to use nanoparticles. The aim of this study was to synthesize green zinc oxide (ZnO) nanoparticles and determine its anti-biofilm effects on biofilm gene expression in multidrug-resistant Klebsiella pneumoniae strains. Materials and Methods: In this in vitro study, ZnO nanoparticles were synthesized by green method using zinc nitrate solution and Typha latifolia extract. Its physical and chemical properties were confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and FTIR (Fourier-transform infrared spectroscopy) methods. Its antimicrobial and anti-biofilm effects against multidrug-resistant Klebsiella pneumoniae isolates were investigated using minimum inhibitory concentration and plate microtiter methods, respectively. Finally, the effects of ZnO nanoparticles on the expression of wzm biofilm gene were investigated using Real Time PCR. Results: The synthesized ZnO nanoparticles had a spherical morphology and had a size of less than 100 nm. The results also showed that the synthesized ZnO nanoparticles had significant antimicrobial and anti-biofilm effects against multidrug-resistant K. pneumoniae strains and these nanoparticles significantly reduced the expression of wzm biofilm gene (p<0.05). Conclusion: The findings of this study showed that the synthesized ZnO nanoparticles have significant antimicrobial and anti-biofilm effects and in the future, with further studies, these nanoparticles can be used as an anti-biofilm candidate. Key words: Zinc oxide nanoparticles, Klebsiella pneumoniae, Antimicrobial, Anti-biofilm, Biofilm gene expression   Funding: This study was funded by Islamic Azad University, Central Tehran Branch as a research project. Conflict of interest: None declared Ethical approval: The Ethics Committee of the Islamic Azad University, Central Tehran Branch has approved the study design (IAU.AC.IR 22310).   How to cite this article: Kalhor N, Mirzaie A, Hamdi S M M. Anti-biofilm Effects of Zinc Oxide Nanoparticles Synthesized by Leaf Extract of Typha Latifolia on Biofilm Gene Expression in Multidrug-Resistant Klebsiella Pneumoniae Strains: A Laboratory Study. J Rafsanjan Univ Med Sci 2021; 20 (1): 3-22. [Farsi]