In Vitro Evaluation of Antibacterial Activity of Urea Solution Against Ocular Bacterial Isolates

In vitro susceptibility testing was performed with commercially available antibiotic discs, homemade urea discs saturated with urea solution at a concentration of 96 mmol. The weight of urea in one drop = 0.37 mg, in one ml = 10.34 mg (5 microliter/ disc) discs and combined discs (antibiotic discs to which urea solution was added). Combined discs provided better in vitro susceptibility results than antibiotics alone.

Scanning electron micrographs of bacterial isolates incubated overnight with urea solution showed marked disruption of bacterial aggregative patterns and irregularities of their cell walls.

Western blotting showed marked reduction in total proteins in bacterial isolates incubated overnight with urea solution. These findings may explain the possible mechanisms for antibacterial activity of urea solution as a result of protein denaturation.