*Correspondence: dr.saad71@uomustansiriyah.edu.iq (Received: 27 January 2019; accepted: 11 March 2019) Citaton: Saad L. Hamed and Noor A. Hasoon, Molecular Characterizaton of Carbapenemase-Producing Gram-negatve Bacteria Isolated from Clinical Specimens in Baghdad, Iraq, J Pure Appl Microbiol., 2019; 13(2):1031-1040. doi: 10.22207/JPAM.13.2.41 © The Author(s) 2019. Open Access. This artcle is distributed under the terms of the Creatve Commons Atributon 4.0 Internatonal License which permits unrestricted use, sharing, distributon, and reproducton in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creatve Commons license, and indicate if changes were made. Hamed & Hasoon J Pure Appl Microbiol, 13(2), 1031-1040 | June 2019 Artcle 5488 | htps://dx.doi.org/10.22207/JPAM.13.2.41 Print ISSN: 0973-7510; E-ISSN: 2581-690X ReseARCh ARtiCle OPeN ACCess www.microbiologyjournal.org 1031 Journal of Pure and Applied Microbiology Molecular Characterizaton of Carbapenemase- Producing Gram-negatve Bacteria Isolated from Clinical Specimens in Baghdad, Iraq Saad L. Hamed* and Noor A. hasoon Mustansiriyah University, College of Science, Department of Biology, Baghdad, Iraq. Abstract The emergence and spread of carbapenem-resistant Gram-negatve bacteria is a worldwide emerging public health threat responsible for large number of nosocomail infectons. Metallo-β-lactamases including IMP, VIM, and NDM as well as carbapenem hydrolyzing class D β-lactamase (OXA-48 like) are the predominant types that confer resistance to Carbapenem group of antbiotcs. The aim of this study was to identfy the carbapenemase encoding genes among Gram negatve bacteria isolates. 42 isolates were identfed depending on routne morphological tests followed by species identfcaton using the VITEK 2 system. The 16S rDNA gene sequence was used for confrmaton of the detecton of Enterobacteriaceae and Pseudomonas aeruginosa. Antmicrobial susceptbility testng was performed using VITEK 2 system. For phenotypic detecton of carbapenemase actvity, modifed carbapenem inactvaton method (mCIM) was performed. The carbapenemases encoding genes (bla iMP , bla sPM , bla VIM , bla NDM , bla KPC , bla BIC , bla OXA , bla AiM , bla siM , bla GiM , bla DIM ) were amplifed by PCR and the amplifed products were sequenced. Forty two Gram-negatve bacteria isolates including 25 of P. aeruginosa (59.5%) and 17 of Enterobacteriaceae family (40.4%) were identfed. According to PCR-based method results, carbapenemase gene bla OXA -48 was detected in 31(73.8%) of isolates, bla VIM in 23 (54.7%) and bla NDM in 2(4.76%) of isolates. Twelve (28.5%) of isolates harbored a combinaton of bla OXA -48 and bla VIM , (2.4%) coexistence bla OXA -48 and bla NDM gene and (2.4%) of isolates harbored a bla OXA -48, bla VIM and bla NDM genes. No other carbapenemase genes were identfed. Based on the present study, it was concluded that the high prevalence was in bla OXA -48 gene, followed by bla VIM gene among carbapenemase-producing Gram-negatve bacteria isolates. Keywords: Enterobacteriaceae Pseudomonas aeruginosa, Carbapenemases.