The effect of fluoroquinolones and antioxidans on biofilm formation by Proteus mirabilis strains

Abstract

Background Fluoroquinolones are a group of antibiotics used in urinary tract infections. Unfortunately, resistance to this group of drugs is currently growing. The combined action of fluoroquinolones and other antibacterial and anti-biofilm substances may extend the use of this therapeutic option by clinicians. The aim of the study was to determine the effect of selected fluoroquinolones and therapeutic concentrations of ascorbic acid and rutoside on biofilm formation by Proteus mirabilis. Materials and methods The study included 15 strains of P. mirabilis isolated from urinary tract infections in patients of the University Hospital No. 1 dr A. Jurasz in Bydgoszcz (Poland). The metabolic activity of the biofilm treated with 0.4 mg/ml ascorbic acid, 0.02 µg/ml rutoside and chemotherapeutic agents (ciprofloxacin, norfloxacin) in the concentration range of 0.125–4.0 MIC (minimum inhibitory concentration) was assessed spectrophotometrically. Results Both ciprofloxacin and norfloxacin inhibited biofilm formation by the tested strains. The biofilm reduction rate was correlated with the increasing concentration of antibiotic used. No synergism in fluoroquinolones with ascorbic acid, rutoside or both was found. The ascorbic acid and rutoside combination, however, significantly decreased biofilm production. Conclusions Our research proves a beneficial impact of ascorbic acid with rutoside supplementation on biofilm of P. mirabilis strains causing urinary tract infections.

Synthesis, Biological and Molecular Docking Studies of New Polysubstituted 2‐Amino‐3‐Cyano‐4H‐Chromene Derivatives

“…Across literature, we could find only few reports on the biofilm inhibition in P. mirabilis. Allicin at 32 μg/mL showed the maximum reduction in biofilm development by 33.8 % in P. mirabilis strain, [34] 0.4 mg/mL ascorbic acid and 0.02 μg/mL rutoside assisted the therapeutic potential of chemotherapeutic agents (conc 1-4 μg/mL) in inhibiting biofilm formation in P. mirabilis, [35] and 25-100 mg/mL of ethanol extract of propolis on biofilm formation and concentrations of 25-50 mg/mL of ethanol extract of propolis on formed biofilm has been shown to be effective in inhibiting biofilm in P. mirabilis. [36] In our study, we used synthetic molecules, 2-amino-3-cyano-4H-chromene derivatives, and which has inhibited around 40-45 % biofilm (formation or preformed), which is better than the reported studies.…”