Molecular study of blaVIM and blaIMP genes in Acinetobacter baumannii strains isolated from burn patients in Duhok City, Iraq.

Abstract

Acinetobacter baumannii (A. baumannii) is an opportunistic pathogenic bacterium mainly associated with hospital acquired infections and in immunocompromised individuals who stay in hospitals for a long time. In recent years, it has become increasingly resistant to many different types of antibiotics. The production of the metallo-beta-lactamase (MBL) enzyme is one of the primary causes of this resistance. This study aimed to detect the presence of MBL genes that belong to the verona integrin metallo-β-lactamase (bla-VIM) and imipenemase (bla-IMP) groups in the isolates of Acinetobacter baumannii from burn patients. One hundred and seventeen (117) isolates of A. baumannii were obtained from patient specimens using traditional methods followed by using the VITEK 2 (BioMérieux, Les Pennes-Mirabeau, France) identification system. Metallo β-lactamases were detected in the imipenem-resistant strains by using imipenem disks on Muller-Hinton agar. The polymerase chain reaction (PCR) technique was utilized to examine 117 isolates for the detection of MBLs encoding genes such as bla-VIM, and bla-IMP. Imipenem resistance was detected in 78.6% of the patients. The PCR assays of the isolates identified bla-VIM-1, bla-VIM-2, bla-IMP-1 and bla-IMP-2 genes at the rates of 17%, 40.1%, 29.9% and 4.2%, respectively. The findings suggest that the majority of A. baumannii isolates harbour one or more of the detected genes, signifying that the production of MBLs plays a pivotal role in resistance mechanisms.