Phenotypic characteristics and carbapenemase genes in Klebsiella pneumoniae from patients at Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Kathmandu, Nepal

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a critical nosocomial pathogen, associated with a substantial rise in morbidity and mortality. Phenotypic and molecular characterization of key carbapenemase genes in K. pneumoniae isolates is essential for understanding resistance mechanisms, guiding effective antibiotic stewardship and infection control strategies. This cross-sectional study was conducted from November 2023 to April 2024 at Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Kathmandu. Various types of clinical specimens were collected and processed for bacterial isolation and identification. Antimicrobial susceptibility testing was performed, isolates were screened for β-lactamase production. Carbapenem-resistant isolates were subjected to mCIM and eCIM tests to detect carbapenemase. The presence of blaKPC, blaNDM-1, blaVIM, blaIMP and blaOXA-48-like genes was confirmed by polymerase chain reaction. Data were analyzed using Statistical Package for Social Sciences (SPSS). Out of total 812 samples, 21.2% (172/812) were culture positive. K. pneumoniae accounted for 28.5% (49/172) of isolates. More than half of the K. pneumoniae isolates were resistant to carbapenems, fluoroquinolones, aminoglycosides, nitrofurantoin and cotrimoxazole. Multidrug resistance (MDR) was observed in 73.5% (36/49) of isolates. ESBL and AmpC production were detected in 73.5% (36/49) and 44.9% (22/49) of isolates, respectively. Among 29 CRKP isolates, 62% (18/29) and 34.5% (10/29) were MBL and KPC producers respectively. Carbapenemase production was confirmed in 58.6% (17/29), while metallo-carbapenemase activity was seen in 55.1% (16/29) of CRKP isolates. The prevalence of blaNDM-1, blaVIM and blaOXA-48-like were 58.6%, 10.3% and 6.9% in respective CRKP isolates. Co-existence of blaNDM-1and blaVIM was observed in 6.9% (2/29), while blaNDM-1 and blaOXA-48-like in 3.4% (1/29) of the isolates. The study highlights the concerning prevalence of carbapenem-resistant K. pneumoniae in clinical settings, underscoring its role as a significant public health threat. Strengthening antimicrobial stewardship and implementing strict infection control measures are crucial to curb the spread of CRKP.