Evaluation of Antimicrobial and Anti-biofilm Effects of Copper Nanoparticles Synthesized by Artemisia Scoparia Extract Against Multidrug-Resistant Klebsiella pneumoniae Strains and Analysis of Biofilm Gene Expression

Background: Klebsiella pneumoniae is one of the most important hospital opportunistic pathogens that have become resistant to many antibiotics due to biofilm formation. The aim of this study was to synthesize copper nanoparticles using Artemisia scoparia extract, to investigate its antimicrobial and anti-biofilm effects against K. pneumoniae strains. Methods: In this experimental study, 100 clinical samples were collected from different hospitals in Tehran. K. pneumoniae strains were isolated from clinical specimens using microbiological methods. Subsequently, the synthesis of copper nanoparticles was performed by green synthesis method using A. scoparia extract and its properties were examined by scanning electron microscopy (SEM), transmitting electron microscopy (TEM) and X-ray diffraction (XRD) methods. The antimicrobial and anti-biofilm effects of the synthesized copper nanoparticles were investigated and the effect of copper nanoparticles on the expression of mrkA biofilm gene in K. pneumoniae strains was investigated by Real Time PCR. Results: A total of 20 K. pneumoniae strains were isolated from 100 clinical specimens. SEM TEM and XRD results showed that the synthesized copper nanoparticles had a spherical shape and a size of less than 100 nm. The results showed that copper nanoparticles had significant antimicrobial and anti-biofilm effects against K. pneumoniae strains and copper nanoparticles could significantly reduce the expression of mrkA biofilm gene (p <0.05). Conclusion: The results of this study showed that the synthesized copper nanoparticles have significant antimicrobial and anti-biofilm effects. Therefore, this nanoparticle can be used as a drug candidate in future studies.