This study aimed to examine the efficiency of novel bioactive nanostructures represented by silica–titania sieves used as carriers for a new antibacterial agent izohidrafural against bacterial strains isolated from nosocomial urinary tract infections, by using biological quantitative assays. Several release trials have been established and compared with MCM-41 in parallel experiments to achieve the optimum release profile. The obtained systems showed that silica–titania sieves loaded with izohidrafural proved to be the most active material against Klebsiella pneumoniae (average minimal inhibitory concentration [MIC] 40.62 μg/mL), desaminase-positive strains (average MIC 2.925 μg/mL), and Proteus mirabilis (average MIC 9.37 μg/mL), the last being reported with the highest growth rate in the urinary tract catheters. In contrast, the nonloaded silica–titanium sieves exhibited the highest antimicrobial activity against the Gram-positive cocci. Izohidrafural exhibited the highest antimicrobial efficiency, superior to the common drug nitrofurantoin against most Escherichia coli strains, with average MIC of 4.68 μg/mL.