Antibacterial effect of vitamin C against uropathogenic E. coli in vitro and in vivo

BackgroundResistance to antibiotics has increased steadily over time, thus there is a pressing need for safer alternatives to antibiotics. Current study aims to evaluate the influence of vitamin C as an antibacterial and anti-biofilm agent against uropathogenic E. coli (UPEC) strains. The expression of beta-lactamases and biofilm encoding genes among E. coli isolates before and after treating the isolates with sub MIC of vitamin C was analyzed by Real-time PCR. The in vivo assessment of the antibacterial and anti-biofilm effects of vitamin C against uropathogenic E. coli strains was done using a urinary tract infection (UTI) rat model.ResultsThe effective concentration of vitamin C that could inhibit the growth of most study isolates (70%) was 1.25 mg/ml. Vitamin C showed a synergistic effect with most of the studied antibiotics; no antagonistic effect was detected at all. Vitamin C showed an excellent anti-biofilm effect against studied isolates, where 43 biofilm-producing isolates were converted to non-biofilm at a concentration of 0.312 mg/ml. The expression levels of most studied genes were down-regulated after treatment of E. coli isolates with vitamin C. In vivo assessment of vitamin C in treating UTIs showed that vitamin C has a rapid curative effect as the comparable antibiotic. Administration of both vitamin C and nitrofurantoin at a lower dose for treatment of UTI in rats had a better effect.ConclusionVitamin C as an antibacterial and anti-biofilm agent either alone or in combination with antibiotics could markedly improve UTI in experimental rats.

Automated summary

The study aimed to evaluate the influence of vitamin C as an antibacterial and anti-biofilm agent against uropathogenic E. coli strains. It was found that vitamin C could effectively inhibit the growth of most strains and showed a synergistic effect with various antibiotics. Additionally, vitamin C significantly suppressed biofilm formation and down-regulated the expression of related genes. In vivo experiments using a rat model demonstrated that the combination of vitamin C and nitrofurantoin had a better therapeutic effect for urinary tract infections.