en ميکروب شناسي Microbiology Research Article Research Article <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><b>Background:</b> The incidence of healthcare-associated infections (HAIs) is increasing rapidly, primarily driven by multidrug-resistant Gram-negative pathogens, notably <i>Pseudomonas aeruginosa</i> and <i>Acinetobacter</i> spp. Metallo-beta-lactamases (MBLs), including IMP and VIM types, are frequently produced by these organisms and contribute to therapeutic challenges through gene dissemination and prolonged colonization in clinical settings. This study, conducted in Rasht, Iran, aimed to evaluate phenotypic resistance and MBL production in imipenem-resistant clinical isolates of <i>P. aeruginosa</i> and <i>Acinetobacter</i>.<br> <b>Methods:</b> In this descriptive cross-sectional study, 52 <i>Acinetobacter</i> and 25 <i>P. aeruginosa</i> isolates were obtained from healthcare facilities in Rasht. Species identification was confirmed using standard biochemical assays. Antimicrobial susceptibility was assessed using the disk diffusion method in accordance with CLSI recommendations. MBL-producing isolates were screened using the imipenem-EDTA combined disk test. Genomic DNA was extracted with a commercial kit, followed by PCR amplification to detect the <i>bla</i>_IMP and <i>bla</i>_VIM genes.<br> <b>Results:</b> According to the findings of this study, the highest percentage of resistance in <i>Acinetobacter</i> was observed against cefotaxime at 94.23%, and in <i>P. aeruginosa</i> against ceftazidime at 84%. Among the isolates not susceptible to imipenem, 18 (40%) <i>Acinetobacter </i>and 2 (15.38%) <i>P. aeruginosa</i> isolates were identified as MBL producers by the combined disk method. Both <i>P. aeruginosa</i> and <i>Acinetobacter</i> isolates demonstrated high resistance to ceftazidime. The <i>bla</i>_IMP and <i>bla</i>_VIM genes were detected in 7 (13.46%) and 11 (21.15%) <i>Acinetobacter</i> isolates, respectively, and in 8 (32%) and 5 (20%) <i>P. aeruginosa</i> isolates, respectively.<br> <b>Conclusion</b>: Early detection of <i>Acinetobacter</i> and <i>P. aeruginosa</i> strains producing metallo-&beta;-lactamases is key to guiding effective clinical treatment and improving patient outcomes. These results suggest that the <i>bla</i>_IMP and <i>bla</i>_VIM genes play important roles in antibiotic resistance and may potentially influence the virulence of <i>Acinetobacter</i> species and <i>P. aeruginosa</i> in the region.</span></span></div> Acinetobacter, Pseudomonas aeruginosa, Beta Lactamases 0 0 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1787-1&slc_lang=en&sid=1 Zahra Nasirzadeh zahranasirzade94@gmail.com 100319475328460032735 0009-0000-7094-6684 Yes Department of Biology, Ra.C., Islamic Azad University, Rasht, Iran Seyedeh Tooba Shafighi shafighi@iau.ac.ir 100319475328460032736 100319475328460032736 No Department of Biology, Ra.C., Islamic Azad University, Rasht, Iran