Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 49 5 2020 05 01 959 967 EN Ahmad FARAJZADEH SHEIKH Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran AND Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Mojtaba SHAHIN Department of Medical Laboratory Sciences, Faculty of Medical Sciences, Arak Branch, Islamic Azad University, Arak, Iran Leili SHOKOOHIZADEH Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamedan, Iran Fahimeh GHANBARI Student Research Committee, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Hamid SOLGI Department of Bacteriology, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran Fereshteh SHAHCHERAGHI Department of Bacteriology, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran 2018 04 14 2018 08 11 Background: New Delhi metallo-beta-lactamase-1 (NDM-1) is one of the most important emerging antibiotic resistance. Co-harboring three or four carbapenemases is rare and only a few reports exist in the literature. We described the characteristics of the large epidemic outbreaks and reports co-producing blaNDM-1 with the other carbapenemase genes in P. aeruginosa isolates. Methods: This present cross-sectional research was conducted on 369 P. aeruginosa isolates obtained from burn and general hospitals within years 2013 to 2016. Beta-lactamase classes A, B and D genes were identified by PCR method. Modified hodge test (MHT), double-disk potentiation tests (DDPT) and double disk synergy test (DDST) were performed for detection carbapenemase and metallo beta-lactamase (MBL) production of blaNDM-1 positive P. aeruginos isolates. Results: From 236 carbapenem-resistant P. aeruginosa (CRPA), 116 isolates have had MBL genes and twenty-nine isolates were found positive for blaNDM-1. In CRPA isolates, blaIMP-1, blaVIM-2 and blaOXA-10 were identified in 27.5%, 21.1% and 32.2% of isolates respectively, while co-producing blaNDM-1, blaIMP-1, blaOXA-10, co-producing blaNDM-1, blaVIM-2, blaOXA-10 and co-producing blaIMP-1, blaVIM-2 were determined in 11 (4.6%), 8 (3.4%) and 27 (11.4%) of isolates respectively. Conclusion: The finding of this co-existence of multiple carbapenemase resistance genes is threating for public health. Dipicolinic acid is a superior MBL inhibitor in DDPT antique than EDTA in DDST method for the detection of MBL-blaNDM-1 producing P. aeruginosa. https://ijph.tums.ac.ir/index.php/ijph/article/view/13090 https://ijph.tums.ac.ir/index.php/ijph/article/download/13090/6918