The Effect of rsbA Gene Expression by TiO2 Nanoparticles in Clinical Isolates of Proteus mirabilis

Background: Urinary tract infections (UTIs) are primarily caused by Proteus mirabilis, especially in patients who have catheterization or structural urinary abnormalities. The rsbA gene controls the organism's robust swarming motility, which enhances virulence and infection persistence. Alternative antimicrobial methods are required because clinical P. mirabilis isolates have become more resistant due to antibiotic misuse. Methodology: The antibacterial and anti-swarming properties of titanium dioxide nanoparticles (TiO₂ NPs) were examined in this work, along with their impact on the expression of the rsbA gene in clinical isolates sourced from hospitals in Baghdad. Results: Using the VITEK 2 system, biochemical testing, and cultural traits, 35 isolates from 57 urine samples were determined to be P. mirabilis. Testing for antibiotic susceptibility showed high rates of resistance, especially to ceftriaxone (60%) in particular.15 mg/ml was found to be the TiO₂ NPs' minimum inhibitory concentration (MIC). Swarming motility was considerably decreased in all tested isolates at sub-MIC concentrations. Following treatment with TiO₂ NPs, quantitative real-time PCR analysis showed a down-regulation of rsbA expression, suggesting interference with the regulation of motility and virulence. Conclusion: These results imply that TiO₂ nanoparticles, which target swarming behavior and virulence gene expression, may be a promising supplementary antimicrobial treatment to control multidrug-resistant P. mirabilis.