Iranian Journal of Pathology | ISSN: 2345-3656 Article Info KEYWORDS ABSTRACT Vol.13 No.3 Summer 2018 IRANIAN JOURNAL OF PATHOLOGY Prevalence of bla Oxacillinase-23- and bla Oxacillinase-24/40- type Carbapenemases in Pseudomonas aeruginosa Species Isolated From Patients With Nosocomial and Non-nosocomial Infections in the West of Iran Samaneh Rouhi 1,2 , Rashid Ramazanzadeh 2,3* 1. Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran 2. Cellular and Molecular Research Center, Health Development Research Institute, Kurdistan University of Medical Sciences, Sanandaj, Iran 3. Microbiology Dept, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran Background and Objective: Pseudomonas aeruginosa (P. aeruginosa) cause serious noso- comial and non-nosocomial infections. The bla Oxacillinases (OXA)-23 and bla OXA24/40 induce resistance to carbapenems. The current study aimed at detecting blaOXA-23 and blaOXA-24/40 in P. aerugi- nosa strains isolated from patients with nosocomial and non-nosocomial infections. Methods: The current descriptive cross sectional study was conducted in Sanandaj, Iran (Kurdistan Province) from December 2015 to August 2017, on 146 strains of Pseudomonas spp. isolated from patients’ specimens. Microbiological methods and polymerase chain reaction (PCR) for gyrB were applied to detect P. aeruginosa. Imipenem (IMP)-disk diffusion method and OXA-23-/OXA-24/40-multiplex PCR were used to identify resistant strains. Stata 12 using Fisher exact test and logistic regression were employed to analyze the data (P ≤0.05). Results: The gyrB-PCR results showed that 91.78% of isolates were P. aeruginosa. Nosoco- mial infection caused by P. aeruginosa was observed in 41.79% of the studied patients; howev- er, 27.61% of P. aeruginosa strains were resistant to IMP; bla OXA-23 and bla OXA24/40 were detected in 11.19% and 2.24% of the strains, respectively; a co-existence of bla OXA-23 and bla OXA24/40 was also observed in 2.23% of P. aeruginosa strains. There were no significant relationships be- tween antibiotic resistance and harboring resistance genes; in addition, between IMP resistance and age, gender, place of residence, inpatient/outpatient, and type of specimen no association was found (P≥ 0.05). Conclusion: Resistance to IMP and the detection of resistant genes in the current study were observed in the clinical samples. Antibiotics should be prescribed more cautiously in order to prevent antibiotic resistance in pathogens. Carbapenemase genes, Metallo-beta-lactamases, OXA-carbapenemases, Pseudomonas aeruginosa Corresponding information: Copyright © 2018, IRANIAN JOURNAL OF PATHOLOGY. This is an open-access article distributed under the terms of the Creative Commons Attribution-non- commercial 4.0 International License which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited. Rashid Ramazanzadeh, Cellular and Molecular Research Center, Health Development Research Institute, Kurdistan University of Medical Sciences, Sanandaj, Iran. Microbiology Dept, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran E-mail: atrop_t51@yahoo.com Introduction Pseudomonas aeruginosa (P. aeruginosa) is the most common bacterial pathogen found in serious nosocomial and also non-nosocomial infections. Some of the infections caused by these bacteria are pneumonia, urinary tract infection (UTI), surgical site infections, and sepsis (1, 2). These bacteria are often associated with multi-drug resistance (MDR) and extensively drug resistance (XDR). Thus, differ- ent infections caused by P. aeruginosa are difficult to treat and lead to morbidity, mortality, and also high economic burden on the patients (1). P. aeruginosa Original Article | Iran J Pathol.2018; 13(3):348-356 Received 15 May 2018; Accepted 10 Aug 2018; Published Online 12 Sep 2018;