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.