Antibacterial Effect of Seidlitzia rosmarinus Extract and Silver Nanoparticles on Staphylococcus aureus and Klebsiella pneumoniae Isolated from Urinary Tract Infections

Background: The prevalence of bacterial drug resistance and consequently the reduction of antibiotic effects on bacteria encourages researchers to seek appropriate and low-risk alternatives for treatment of infectious diseases. Nanoparticles and herbal extracts can be considered as good alternatives to antibiotics. The aim of this study was to investigate the antimicrobial effect of silver nanoparticles in comparison to Seidlitzia rosmarinus extract on multidrug resistant (MDR) strains of Staphylococcus aureus (S. aureus) and Klebsiella pneumoniae (K. pneumoniae). Methods: S. aureus and K. pneumoniae were isolated from urinary tract infections. Doses of 50, 100, 200, and 400 mg/mL of alcoholic extract of Seidlitzia rosmarinus and also 5, 10, 20, and 80 g/mL of silver nanoparticles were added to Agar with S.aureus or K. pneumoniae. Then, Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. Results: Seidlitzia rosmarinus extracts conferred a noticeable effect on S. aureus (MIC = 100 mg/mL and MBC = 100 mg/mL), while silver nanoparticles were a higher inhibitory effect on K. pneumoniae (MIC = 5 g/mL and MBC = 10 g/mL). Both the extract and nanoparticles inhibited dose dependently the growth of S. aureus and K. pneumoniae. Conclusions: It seems that Seidlitzia rosmarinus extract and silver nanoparticles prevent the growth and proliferation of S.aureus and K. pneumoniae in a dose dependent manner.