Detection of carbapenemases activity in MDR isolates of Klebsiella pneumoniae by mCIM method and carbapenem resistance genes blaVIM, blaIMP, blaNDM, blaKPC-2 and blaOXA-48

Abstract Klebsiella pneumoniae (K. pneumoniae) is a Gram-negative, opportunistic bacterium that can cause a variety of infections. Antibiotics such as cephalosporins are usually used to treat K. pneumoniae infections. However, resistance of this bacterium to cephalosporins has been reported. For this reason, alternative antibiotics such as carbapenems are used as the last line of treatment for K. pneumoniae. This bacterium becomes resistant to carbapenems by various mechanisms, including enzymatic hydrolysis of carbapenems by producing carbapenemase enzymes (blaVIM, blaIMP, blaNDM, blaKPC−2 and blaOXA−48 genes produce the hydrolysis enzyme). The present study aims to investigate the prevalence rate of MDR K. pneumoniae and the evaluation of resistant isolates to carbapenem was done using phenotypic and genotypic methods. In the present study, 205 K. pneumoniae isolates were collected from patients admitted to the Hospitals of Tabriz University of Medical Sciences from November 2022 to April 2023. Antibiotic susceptibility patterns were determined by disc diffusion method and resistance genes of blaVIM, blaIMP, blaNDM, blaKPC−2 and blaOXA−48 were detected by PCR method. Out of 205 samples collected from K. pneumoniae isolates, 100 samples were multidrug resistant (MDR). Of the 100 MDR K. pneumoniae isolates, 80 samples (%80) were resistant to carbapenems by mCIM method. The frequencies of the blaOXA, blaNDM, blaIMP, blaVIM and blaKPC−2 genes were 52 (65%), 23(28.7%), 12 (15%), 8 (10%) and 5 (6.25%), respectively. Antimicrobial resistance was common and worrying, and rapid and accurate detection of MDR K. pneumoniae isolates can help in the management of patients with K. pneumoniae infections and reduce mortality. Rapid detection of MDR K. pneumoniae can also prevent the spread of resistant isolates.