Traditional and Molecular Gene Detection (blaIMP-1 and blaIMP) of multi-drug resistant Acinetobacter baumannii

Abstract

Acinetobacter bacteria are widely resistant to β-lactam antibiotics. The formation of carbapenemases such metallo-β lactamases (MBLs), which hydrolyze a variety of β-lactams including penicillin, cephalosporins, and carbapenems, is one of the primary causes of resistance in Acinetobacter baumannii. MBL-producing carbapenem-resistant strains have been detected all over the world in recent years, and at a rising pace. For this investigation, fifty-two A. baumannii isolates were chosen based on imipenem (IMP) resistance (MIC >16 g/ml). The Modified Hodge test (MHT) and the CDDT were used to detect MBL phenotypic expression (Combine Disk Diffusion Test). PCR was used to detect genotypic expressions of the blaIMP-1 and blaIMP genes in all metallolactamase-producing A. baumannii strains. According to the MHT test, 49 of 52 A. baumannii isolates (94.2%) produced carbapenemase, whereas the CDDT test revealed that 47 isolates (90.4%) produced MBL. Despite being negative for MBL-producer in the phenotypic technique used for control isolates, 39 (75%) of 52 putative MBLproducer isolates were positive for the blaIMP-1 gene by PCR, while fifteen A. baumannii isolates (28.8%) were positive for the blaIMP gene by PCR. In 23% (12/52) of instances, the blaIMP-1 and blaIMP genes were found together. The genotypic approach must be used to confirm isolates of A. baumannii that have been identified as MBL-producers using the MHT test and the Combine Disk Diffusion Test.