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

Background and objective: pseudomonas aeruginosa (p. aeruginosa) cause serious nosocomial and non-nosocomial infections. the blaoxacillinases (oxa)-23 and blaoxa24/40 induce resistance to carbapenems. the current study aimed at detecting bla_oxa-23 and bla_oxa-24/40 in p. aeruginosa 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. nosocomial infection caused by p. aeruginosa was observed in 41.79% of the studied patients; however, 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 between 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.