Mohammad Taheri - Department of Medical Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
Ali Mohammad Amani - Department of Medical Nanotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
Shahrbanoo Ghaedi - Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Amir Rabiee - Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Fatemeh Nouri - Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran

Background and ObjectiveThe development of nanotechnology has increased the researchers attention to nanoparticles to inhibit microbial growth. Because of their small size, nanoparticles have unique physical and chemical properties; this reduction in dimensions increases the surface-to-volume ratio of nanoparticles, resulting in a higher level of contact with the microfilm. For this reason, nanoparticles have a higher antimicrobial effect. This study was aimed to investigate the antibacterial effect of PEI—Sicl4 and PEI—Rucl4 nanoparticles on the growth rate of gram-negative bacteria Klebsiella pneumoniae.Materials and MethodsIn the current study, the 0.5 Mcfarland concentration of bacteria were exposed with the 1, 10 and 100 % w/v of nano compounds and were incubated at 35 ºC overnight. Then these bacteria were cultured on the nutrient agar plated and the growth inhibition of this compounds was evaluated. Furthermore, nanostructures were loaded on the blank discs in different concentrations. A disc containing nanomaterials put on the nutrient agar plates that were inoculated with a specific account of bacteria. Then these plates were incubated at the 35 ºC for 18 hours. Inhibition zone diameter of each disc was measured as mean ± SD. Data were analyzed using SPSS version 22 and were compared by Student t-test. P-value ≤ 0.05 was considered significant.ResultsThe antibacterial findings showed that the PEI—Sicl4 and PEI—Rucl4 have an equally significant antibacterial effect on the pathogenic bacteria K. pneumoniae in concentrations used.ConclusionCombination therapy with the metal nanoparticles might be one of the possible strategies to overcome the current bacterial resistance to the antibacterial agents. However, further studies should be performed to minimize the toxicity of nanoparticles to apply as proper alternatives to antibiotics and disinfectants, especially in biomedical applications.

Nanoconjugate, Antibacterial susceptibility, Klebsiella pneumoniae, Antibiotic resistance