en بیوتکنولوژی Biotechnology پژوهشي Research <div style="text-align: justify;"><strong>Background</strong>: <em>Pseudomonas aeruginosa</em> is the primary cause of infection with impaired defense mechanisms. <em>P. aeruginosa</em> commonly causes nosocomial infections and is the most common pathogen isolated from patients hospitalized for longer than 1 week. We examined the antimicrobial effect of multilayered carbon nanotubes on multi-drug-resistant<em>.</em><br> <strong>Materials and methods</strong>: In this research, 20 clinical isolates collected at Motahari Hospital (Tehran, Iran) were compared with the standard (ATCC 27853) and identified as <em>P. aeruginosa</em> based on biochemical testing. Conventional disk diffusion assay demonstrated the methicillin resistance of the isolates. Minimal inhibitory concentrations for antibiotics and the multilayer CNTs were determined using the microdilution method. Single-walled CNTs were prepared and their efficacy and potential &nbsp;synergism with antibiotics was assessed.<br> <strong>Results</strong>: Synergism against <em>P. aeruginosa</em> was evident for methicillin + single-walled CNTs.<br> <strong>Conclusion</strong>: The inhibitory effect of single-walled CNTs and methicillin was synergistic against the growth of <em>P. aeruginosa</em>.</div> antimicrobial, nanoparticle, multilayered carbon nanotubes, nanomedicine, Pseudomonas aeruginosa 38 47 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-914-3&slc_lang=en&sid=1 Hadis Mousavi h.mosavi328@gmail.com 10031947532846007766 10031947532846007766 No Department of Microbiology, Faculty of Science, Islamic Azad University, Hamedan, Hamedan, Iran Hamideh Rouhani nejad rohaninejhad@gmail.com 10031947532846007767 10031947532846007767 Yes Malek-Ashtar University of Technology, Tehran, Iran Masoud Zandi mzandi49@yahoo.com 10031947532846007768 10031947532846007768 No Department of Nursing and Midwifery, Tuyserkan Branch, Islamic Azad University, Tuyserkan, Iran Amir Khodavirdipour 10031947532846007769 10031947532846007769 No Division of Human Genetics, department of anatomy, St. John’s hospital, Bangalore, INDIA