Antimicrobial and anti-biofilm activities of photosynthesized Ag@TiO₂ and Ag@N-TiO₂ nanocomposites against clinically isolated multidrug resistance Klebsiella pneumoniae

Abstract

The rise of drug-resistant bacterial strains is escalating due to the ability to produce biofilms shielding bacteria from antimicrobial agents. Consequently, novel approaches are imperative for managing biofilm-related infections in healthcare settings. Silver-based nanoparticles have revealed potential antimicrobial characteristics against various bacteria. In the present work, silver-modified TiO2 (Ag@TiO2) and silver-modified/N-doped TiO2 (Ag@N-TiO2) nanocomposites were synthesized using the sol–gel and photochemical deposition under UV light illumination. FTIR, XRD, and DRS were performed to characterize the vibrational, structural, and optical properties of the synthesized materials, respectively. In addition, FE-SEM and EDX analysis were also utilized to determine the surface morphology, particle size, and elemental composition of the prepared materials. Furthermore, the synthesized Ag@TiO2 and Ag@N-TiO2 nanocomposites were explored and compared for antimicrobial and anti-biofilm agents against clinically isolated multidrug-resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) on the silicone rubber as a urinary catheter material in the medical devices. The results showed that both Ag@TiO2 and Ag@N-TiO2 composites exhibited antimicrobial activities compared to negative control. The Ag−3@TiO2 composite possessed a highest inhibition zone (77.29%) against MDR K. pneumoniae. In addition, anti-biofilm assay through the crystal violet method showed that Ag−1@TiO2 revealed an optimum inhibition (54.20%) compared to other samples. In conclusion, Ag@TiO2 and Ag@N-TiO2 nanocomposites have exhibited promising antimicrobial and anti-biofilm agents in medical devices, providing an effective inhibition toward the bacterial growth and biofilm formation of MDR K. pneumoniae.