Effect of levofloxacin and vitamin C on bacterial adherence and preformed biofilm on urethral catheter surfaces

Abstract

The effect of levofloxacin (LEV) and vitamin-C (VIT-C) individually or in combinations on initial bacterial adherence and pre-formed (mature) biofilms on the surface of urethral catheters was studied. The isolated and studied uropathogens in the present study showed considerable diversity, where the major pathogens were identified as E.coli, Klebsiella sp., Citrobacter sp., Enterobacter sp., Proteus sp. and Pseudomonas sp. Using the static adherence assay, addition of LEV and VIT-C each alone at sub MIC concentrations (0.25 MIC and 0.5 MIC) and (80 and 100 mg ml-1) respectively, reduced the initial adherence ability of bacteria to the catheter by 35-94%. Besides, the inhibitory effect on the mature biofilm was estimated to be 40-90% in the presence of (MIC and 2MIC) LEV or (80 and 100 mg/ml) VIT-C. The highest inhibitory effects on both the initial adherence and mature biofilm were recorded when 0.5 MIC levofloxacin was added. Combination of LEV and VIT-C significantly increased the inhibitory effect of both initial biofilm formation and the mature biofilm to 80-100%. In addition, scanning electron microscope (SEM) was used to verify the effect of the tested drugs on biofilm production. The obtained results confirmed the significant role of this combination in inhibition of urethral catheter biofilm formation. © 2012 El-Gebaly E, et al.