Introduction: Carbapenems are one of the latest drugs for treatment of threatening infections of Pseudomonas aeruginosa. Resistance to these antibiotics is sometimes caused by carbapnmase class B, such as VIM metallo-beta-lactamase (MBL) that is growing in the communities. The aim of this study was to detect the of metallo-beta-lactamase bla_VIM-1 gene among clinical isolates of Pseudomonas aeruginosa in Mashhad.

Methods: In this cross-sectional study, 70 isolates of Pseudomonas aeruginosa were collected from samples of inpatients at hospitals in Mashhad. Bacteria were identified by conventional biochemical methods. Antibiotic susceptibility testing was examined in accordance with the Kirby-Bauer method. Metallo-beta-lactamase- producing isolates were identified using a combination disc of imipenem and EDTA. Then, polymerase chain reaction was performed using specific primers to detect bla_VIM-1 gene.

Results: 25 (35.7%) out of 70 isolated bacteria had metallo-beta- lactamase, which bla_VIM-1 gene were detected in the genome of 8 isolates. 65.6% of resistant bacteria to imipenem produced metallo-beta-lactamase (MBL). A higher percentage of MBL- producing isolates were resistant to imipenem, meropenem, carbenicillin and cefotaxime (p < 0.05).

Conclusion: The results of the study showed that antibiotic resistance among examined clinical isolates of Paeruginosa was high and VIM-type metallo-beta-lactamase was detected among them. Identification of bacteria with metallo-beta-lactamase (MBL) is very important in the prevention and treatment of infections resistant to antibiotics.