Identification of Imipenem-Resistant Genes in Acinetobacter baumannii Isolated from Baghdad Hospitals

Imipenem-resistant Acinetobacter baumannii (IRAB) represents one of the important causing agents of nosocomial infections especially in immunocompromised and Intensive Care Units (ICUs) patients. The aim of this work was to identify the Imipenem-Resistant genes in Acinetobacter baumannii isolated from Baghdad hospitals. Among 128 A. baumannii isolates, 67 isolates (58.26%) were resistant to imipenem and meropenem. Four genes for imipenem resistance (blaOXA-23 like, blaOXA-24 like, blaOXA-51like and blaOXA-58 like) were amplified and sequenced. The presence of blaOXA-23-like genes in 91.03% of IRAB isolates indicated that the blaOXA-23-like genes are the predominant mechanism for imipenem resistance in our isolates. Sequencing of PCR products showed the presence of new OXA-genes in local A. baumannii isolates including: OXA-207, OXA-239 and OXA-229 among the genes of OXA-24-like, OXA-23-like and OXA-58-like genes, respectively. In conclusion, this study identifies the genes responsible for the imipenem resistance in Baghdad which is important to understand the imipenem resistance and to suggest plans for treatment of patients in future.