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

The rise of drug-resistant bacterial strains is escalating due to the ability to produce biofilms shielding bacteria from anti
microbial agents. Consequently, novel approaches are imperative for managing biofilm-related infections in healthcare set
tings. 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 char
acterize 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 com
posite 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