Abstract
Background: The use of carbapenem antibiotics in the treatment of serious Gram-negative bacterial infections is under threat due to the emergence of the bla(IMP) gene amongst the bacterial pathogens.
Methods: The present descriptive cross-sectional study aimed to determine the occurrence of the bla(IMP) gene and minimum inhibitory concentrations (MICs) of the bacterial pathogens. The carbapenem-resistant isolates were screened out for the detection of MBLs by using the modified Hodge test and disk potentiation method. MBL producing strains were tested for the presence of the bla(IMP) gene by using PCR technique. The MICs of the b/a m p gene positive bacterial isolates were detected on the Vitek 2 system (bioMerieux).
Results: The primary source of MBLs and bla(IMP) gene carrying bacterial pathogens was blood (38.5%). We isolated 104 bacterial isolates in the initial screening of carbapenem resistance. Metallo-beta-lactamases (MBLs) were detected in 76 (73%) of the isolates which predominantly included 27 (26%) Klebsiella pneumoniae, 20 (19.2%) Acinetobacter baumannii, 16 (15.4%) Pseudomonas aeruginosa, and 11 (10.6%) E. coli while the other Gram-negative MBL producing bacteria were few in number. The bla(IMP) gene was detected in 1 (1.3%) case of Acinetobacter baumannii and 1 (1.3%) case of Stenotrophomonas maltophilia. These strains were found to be multi-drug resistant with high MICs (>= 8 to >= 256 mu g/mL) against the majority of the drugs.
Conclusions: The emergence of the bla(IMP) gene is a matter of serious concern as it left us with limited treatment options of minocycline, tigecycline, and levofloxacin. The horizontal transfer of bla(IMP) gene in other Gram-negative isolates can lead the epidemics of multidrug resistance.