Biotechnology & nanotechnology
Fadhl Rajeh Swade; farahnaz molavi; samaneh dolatabadi
Volume 29, Issue 3 , September and October 2022, , Pages 421-434
Abstract
Introduction: At present, Pseudomonas aeruginosa bacteria has caused many problems to control nosocomial infections due to its resistance to various antibiotics and MexAB-OprM efflux pumps play an important role in making Pseudomonas aeruginosa strains resistant to antibiotics. The aim of this study ...
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Introduction: At present, Pseudomonas aeruginosa bacteria has caused many problems to control nosocomial infections due to its resistance to various antibiotics and MexAB-OprM efflux pumps play an important role in making Pseudomonas aeruginosa strains resistant to antibiotics. The aim of this study was to determine the antimicrobial effect of silver nanoparticles and probiotic Lactobacillus plantarum on MexA gene expression.
Materials and Methods: In this descriptive cross-sectional study, 49 strains were collected from 8 medical diagnostic laboratories in Mashhad during the years 1398-1399 for 8 months. Evaluation of antibiotic susceptibility pattern of strains was using disk diffusion method based on CLSI protocol. After treatment of multidrug resistant bacteria with inhibitors, microdilution method and Real time-PCR technique were used to determine the effective dilution of silver nanoparticles and probiotics on the expression of MexA gene of its producing bacterium, respectively.
Results: All samples were identified and all of them were resistant to more than two antibiotics and had MexA gene. The minimum growth inhibition concentration in agar dilution method was up to 250 μg / ml for silver nanoparticles and up to 18 μg / ml for probiotics. Silver nanoparticles had a greater effect in inhibiting bacterial growth compared to probiotics and this effect is less than the combined effect of probiotics and silver nanoparticles (P> 0.05).
Conclusion: Silver and probiotic nanoparticles have inhibitory and antibacterial activity to reduce the performance of MexAB-OprM efflux pump in Pseudomonas aeruginosa. (P> 0.05).
Mohsen Khosroabadi; Mehdi Bakhshabadi; Alireza Golshan; Mohammad Mehrpoyan
Volume 21, Issue 2 , May and June 2014, , Pages 320-331
Abstract
Background: One of the ways to treat prostate cancer is brachytherapy using low-energy sources, such as iodine-125 (125I). The purpose of this study was to assess dose enhancement factor in tumors in the presence of various nanoparticles in prostate tumor, and the effect of these nanoparticles on isodose ...
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Background: One of the ways to treat prostate cancer is brachytherapy using low-energy sources, such as iodine-125 (125I). The purpose of this study was to assess dose enhancement factor in tumors in the presence of various nanoparticles in prostate tumor, and the effect of these nanoparticles on isodose curves in prostate cancer brachytherapy using Monte Carlo simulation.
Materials and Method: 125I brachytherapy source model SL-125/SH-125 was simulated using Monte Carlo MCNPX code. TG-43 parameters were calculated and verified. Dose enhancement factors were evaluated in presence of Fe2O3, Ag, Gd, Pt and Au nanoparticles in central cross section of the tumor in concentrations of 7, 18 and 30 mg/ml.
Results: Dose rate constant obtained 0.954 cGyh-1U-1. Maximum dose enhancement factors for Fe2O3, Ag, Gd, Pt and Au were 1.79, 1.32, 1.14, 1.15 and 1.27, respectively. Also, the 100% isodose line shifted toward the central point of the spherical tumor and the 100% isodose line shifted outward. Dose enhancement factors had no rule in increasing or decreasing by atomic number of nanoparticles.
Conclusion: Regarding to the simulation results, it can be concluded that nanoparticles presence in tumor leads to dose increase inside the tumor and dose decrease outside the tumor. Therefore, we can reduce treatment time and activity. So, the clinical use of these nanoparticles is recommended to enhance prostate brachytherapy dose.