Amin Haratian - Department of Cell and Molecular Biology‚ Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
Helia Karimnejad - Department of Cell and Molecular Biology‚ Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
Mohammad Doroudian - Department of Cell and Molecular Biology‚ Faculty of Biological Sciences, Kharazmi University, Tehran, Iran

Background and Aim : Pseudomonas aeruginosa is one of the main bacteria producing biofilm.Biofilm can cause acute bacterial infection. Biofilm formation and motility in this bacterium isunder the control of the quorum sensing system (QS). These bacteria can communicate with eachother using messenger molecules called autoinducer molecules. Hence, disrupting QS is apromising strategy to combat bacterial infection. Several nanoparticles can be used for thispurpose. There is mounting evidence that metal nanoparticles can be effectively used to block QSand inhibit the growth of bacteria, especially Pseudomonas aeruginosa.Methods : In this study, we compared the effect of different anti-QS nanoparticles, includingsilver, nickel oxide, zinc oxide, gold, and selenium, on QS performed in individual studies onPseudomonas aeruginosa - both clinical strains as well as laboratory strains. All these particlessuccessfully inhibited biofilm production by more than ۹۰% in laboratory strains such as PAO۱and PA۱۴ and clinical strains extracted from cystic fibrosis patients. Another factor consideredwas the minimum inhibitory concentration (MIC) for each of the nanoparticles. The MIC of zincoxide, silver, nickel oxide, selenium, and gold nanoparticles in mg/ml was ۲۴.۴۱۴, ۰.۰۷۸-۰.۱۵۶,۰.۰۵, ۰.۰۰۴۶-۱.۱۸۴۴, and ۰.۰۰۹۲-۰.۰۳۶۹, respectively.Results : As a result, gold nanoparticles needed the lowest concentration to stop the growth of allPseudomonas aeruginosa strains. In the end, to determine the best option, we considered theproduction process and its justification as an important factor. The production of silvernanoparticles had a better economic and environmental justification. This nanoparticle can beproduced by photochemical, biological and biosynthetic methods, but producing goldnanoparticles costs more.Conclusion : Nanoparticles are very promising options for fighting antibiotic-resistant bacteria,and according to laboratory evidence, silver nanoparticles can be one of the best options fordisrupting QS and fighting infectious bacteria such as Pseudomonas aeruginosa. Also, thisnanoparticle can prevent the growth and production of biofilm in these bacteria.

Pseudomonas aeruginosa, Anti-quorum sensing, Nanoparticles, Nanomedicine,Biofilm inhibition, Minimum Inhibitory Concentration