Antimicrobial activity of gentamicin-conjugated monometallic and bimetallic nanoparticles against multidrug-resistant Klebsiella pneumoniae strains

Abstract

Multidrug-resistant Klebsiella pneumoniae (MDR-KP) poses a significant clinical challenge due to limited therapeutic options and high mortality. This study investigated the antimicrobial efficacy of gamma-irradiation-synthesized gentamicin-conjugated silver nanoparticles (Gent-Ag NPs), copper oxide nanoparticles (CuO NPs), and bimetallic Ag-CuO NPs against three MDR-KP isolates in comparison with the gamma-irradiated gentamicin alone. Gent-Ag, Gent-CuO, and bimetallic Gent-Ag-CuO NPs were synthesized via gamma-radiation-induced reduction and characterized by different analytical methods to confirm their shape, size, surface morphology, particle size distribution, and crystallinity using HRTEM, SEM, DLS, and XRD, respectively. Comparative analysis demonstrated that Gent-Ag NPs exhibited superior antimicrobial activity, while Gent-CuO NPs showed diminished efficacy. SEM imaging analysis showed that Gent-Ag-CuO NPs effectively damaged and weakened the bacterial surfaces. It should be noted that the complete lys of K. pneumoniae cells is depicted by the white holes seen inside the bacteria. These findings suggest potential therapeutic applications of Ag-based NPs against MDR-KP, warranting further validation with larger sample sizes.