Carbapenems antibiotics are an effective treatment option for serious infections, especially that caused by Gram-negative bacilli excluding Pseudomonas aeruginosa strains. Significantly increasing the resistance rate to carbapenems may reduce the choice of these effective antibiotics. Mainly the production of carbapenemes (carbapenem-hydrolysis enzymes) causes resistance to these antibiotics. This study was aimed to detect the occurrence of blaIMP, blaVIM (class A), blaKPC (class B) and blaOXA-40 and blaOX-50 (class D) genes in P. aeruginosa carbapenem-resistant isolates recovered in Najaf-hospitals. From various clinical samples, we identified fifty two isolates as P. aeruginosa. Thirteen of the isolates were non-susceptible to carbapenems. Of these were carbapenemase positive in nine isolates. The most frequent gene was found blaOXA-50 followed by blaVIM, and blaKPC. Coexistence of blaOXA-50 and blaVIM was found in 4 isolates, and not detect of blaIMP and blaOXA-40 genes. All isolates that the carbapenem resistant genes had an extensive drug resistant (XDR) phenotype. In a conclusion, currently widely occurrence of P. aeruginosa carbapenemase genes in Najaf hospitals, this risk in the increase the spreading of XDR isolates in the hospitals. In addition this is the first report of KPC β-lactamase producing by P. aeruginosa in Iraq.
