en Anti-microbial agents, resistance and treatment protocols Anti-microbial agents, resistance and treatment protocols Original article Original article <p dir="ltr" style="margin-right: 0.5in;"><strong>Introduction:</strong> <em>Pseudomonas aeruginosa</em> is one of the leading causes of nosocomial infections, and antibiotic resistance of this pathogen is an important concern in treating such infections. The current work was conducted to investigate the prevalence of <em>bla-IMP,</em> and <em>bla-VIM</em> metallo-beta-lactamase (MBL) among clinical and environmental <em>P. aeruginosa</em> isolates obtained from ICUs of different hospitals in Rasht, Iran. <strong>Methods:</strong> A total number of 35 <em>P. aeruginosa</em> strains including 20 clinical and 15 environmental strains were isolated from ICUs. The isolated bacteria were screened for MBL production using Combined Disc Synergy Testing (CDST) assay. The frequency of <em>bla-IMP</em> and <em>bla-VIM</em> among MBL producing <em>P. aeruginosa</em> (MBL-PA) was investigated using Polymerase Chain Reaction (PCR). Also, the antibiotic susceptibility of all isolates was determined. <strong>Results:</strong> According to the results, 51% of isolates were regarded as MBL-PA while <em>bla-IMP</em> or <em>bla-VIM</em> genes were detected in 37% of isolates. The environmental isolates showed higher resistance to the majority of antibiotics compared to the clinical isolates, and MBL genes were more prevalent among environmental isolates. <strong>Conclusion:</strong> Higher resistance of environmental <em>P. aeruginosa</em> strains in ICUs shows a need to pursue newer approaches, including novel cleaning methods and surveillance programs, to reduce nosocomial infections.</p> Carbapenems, Antibiotic resistance, Metallo-Beta-Lactamase, Nosocomial infection 62 66 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-120-1&slc_lang=en&sid=1 Matin Saberi m.saberi@gmail.com No Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran Hojjatolah Zamani h_zamani@guilan.ac.ir Yes Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran Ali Salehzadeh salehzadehmb@yahoo.com No Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran