Distribution of Carbapenemase Genes among Carbapenem-Resistant Klebsiella pneumoniae Isolates from the Patients in Najaf, Iraq

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global threat, causing serious community- and hospital-acquired infections with limited treatment options. Understanding the local epidemiology of CRKP is crucial for guiding antimicrobial stewardship and infection control measures. This study aimed to investigate the phenotypic characteristics, antimicrobial resistance profiles, and carbapenemase genes among CRKP isolates from the patients in Najaf, Iraq. Methods: This cross-sectional research was performed at diverse hospitals and centers in Najaf, Iraq, from September 2023 to March 2024. The study was approved by the Ethics Committee of Kufa University. CRKP isolates were collected from various health-care facilities and tested for hypermucoviscosity, antimicrobial susceptibility, and carbapenemase production using phenotypic methods. The presence of carbapenemase genes (blaNDM, blaVIM, blaKPC, blaOXA-48, blaOXA-23, and blaOXA-51) was examined by polymerase chain reaction. Results: Of the 27 CRKP isolates, 9 (33.3%) exhibited a hypermucoviscous phenotype. Regarding antimicrobial resistance, 12 (44.4%) were multidrug resistant, 14 (51.9%) were extensively drug resistant, and 1 (3.7%) was pandrug resistant. Phenotypic carbapenemase production was detected in 5 (18.5%) and 11 (40.7%) isolates by the modified Hodge test and E-test metallo-β-lactamase strips, respectively. Molecular analysis revealed that all CRKP harbored the blaOXA-51 gene, whereas blaNDM, blaOXA-23, and blaVIM were detected in 70.4%, 40.7%, and 11.1% of the isolates, respectively. Neither blaKPC nor blaOXA-48 genes were found. In addition, 22 (81.5%) isolates carried multiple carbapenemase genes. Conclusions: The high prevalence of blaOXA-51 and blaNDM carbapenemases, along with the high rates of multidrug resistance among CRKP isolates in Najaf, Iraq, are alarming. This necessitates the immediate implementation of effective antimicrobial stewardship and infection control measures to prevent the further spread of these difficult-to-treat pathogens.