Antibiotics Resistance Profile of Carbapenemase-Producing Klebsiella Pneumoniae Isolates of Clinical Origin With Plasmid-Borne Blandm-1 Gene in Cross River State, Nigeria

Carbapenems are last-line antibiotics for treating multidrug-resistant (MDR) Gram-negative bacterial infections. The emergence of Klebsiella pneumoniae producing New-Delhi-Metallo-β-lactamase (NDM-1) compromises their clinical utility, particularly in hospital settings. This study compared the antibiotic resistance profiles of K. pneumoniae isolates with and without the blaNDM-1 gene from hospitalized patients in Cross River State, Nigeria. Urine and stool samples were collected from admitted patients and cultured on meropenem-supplemented media to isolate carbapenem-resistant Gram-negative bacilli (GNB). K. pneumoniae was identified using Microbact 12A kits, and antibiotic susceptibility was tested using the Kirby-Bauer method. Carbapenemase activity was assessed phenotypically using modified Carbapenemase Inactivation Method and EDTA-modified Carbapenemase Inactivation Method, and blaNDM-1was detected via monoplex PCR. Ethical approval was obtained from the Cross River State Medical Research Ethics Committee. Of the 129 GNB isolates, 24.8% (32/129) were K. pneumoniae, and 50% (16/32) of these were MBL producers. The blaNDM-1 gene was detected in 12.5% (2/16) of MBL-producing isolatesboth from male in-patients. These isolates showed pan-resistance (100%) to all tested antibiotics except tigecycline (1/2 susceptible). Among blaNDM-1 negative isolates, susceptibility to carbapenems ranged from 80-83.3%. The carbapenem resistance rate among all K. pneumoniae isolates was 50% (16/32). Multidrug-resistance was observed in 100% (2/2) of blaNDM-1 positive isolates and 50% (15/30) of negative ones (p=0.03). The mean MARI was 0.9 for NDM-1 positive and 0.4 for negative isolates. Plasmids carry multiple antibiotic resistance genes and confer resistance on bacteria to multiple classes of antibiotics. Regular surveillance of antibiotic resistance is needed to inform policies on antibiotic stewardship programmes.