The Variable Nature of Vitamin C-Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

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

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.

Biofilm Formation Reducing Properties of Manuka Honey and Propolis in Proteus mirabilis Rods Isolated from Chronic Wounds.

Chronic wound infections are difficult to manage because of the biofilm formation in the wound environment. New measures for eliminating infections are necessary to increase the chance of wound healing. Apitherapy may be the new solution. The aim of this study was to assess the prevalence of wound infection factors and to examine the impact of Manuka honey and ethanol extract of propolis on biofilm formation of Proteus mirabilis isolated from chronic wound infections. According to the findings, the most frequent factors of infection are Staphylococcus aureus (46.1%), Pseudomonas aeruginosa (35.0%), and Proteus mirabilis (10.6%). Minimal inhibitory concentration and minimal bactericidal concentration values were assigned using the microbroth dilution test according to the Clinical and Laboratory Standards Institute. Biofilm of Proteus mirabilis isolates was formed in 96-well polystyrene plates and treated with Manuka honey (concentrations from 1.88% to 30.0%) and ethanol extract of propolis (1.0% to 40.0%). After 24 h, the biofilm viability was expressed by formazan absorbance (λ = 470 nm). Manuka honey reduced the biofilm viability in all, and ethanol extract of propolis in most, of the concentrations tested. Ethanol extract of propolis at the concentrations of 20.0% and 40.0%, reduced biofilm viability stronger than ethanol itself. With these results comes the conclusion that these substances can reduce biofilm formation.

Vitamin C in the Presence of Sub-Inhibitory Concentration of Aminoglycosides and Fluoroquinolones Alters Proteus mirabilis Biofilm Inhibitory Rate.

Vitamin C has antimicrobial activity and is often used as an oral supplement accompanying antibiotic treatment in urinary tract infections (UTI). Proteus mirabilis is the third common species responsible for UTIs that are mostly treated with fluoroquinolones or aminoglycosides. Treatment of the UTI caused by P. mirabilis is problematic due to the ability to form biofilm on the urinary catheters. The aim of the study was to evaluate the influence of ascorbic acid in combination with antibiotics on P. mirabilis abilities to form biofilm. The susceptibility of P. mirabilis reference strain ATCC® 29906™ and four clinical strains isolated from the urine samples of patients with urinary catheter were evaluated according to EUCAST recommendations. The influence of ascorbic acid (0.4 mg × mL-1) in combination with antibiotics on biofilm formation was evaluated spectrophotometrically. Aminoglycosides at sub-inhibitory concentrations more successfully limited biofilm formation by P. mirabilis strains without ascorbic acid addition. Inhibition rate differences at the lowest concentrations of gentamicin and amikacin were statistically significant (p ≤ 0.05). Ascorbic acid addition to the culture medium limited the inhibitory effect of fluoroquinolones, facilitating biofilm formation by P. mirabilis strains. The addition of ascorbic acid during aminoglycosides therapy may disturb treatment of urinary tract infections related to the presence of P. mirabilis biofilm.

Antilisterial Activity of Polypropylene Film Coated with Chitosan with Propolis and/or Bee Pollen in Food Models.

The aim of the study was to evaluate the effect of propylene film coated with solution of chitosan (CH), ethanolic extracts of propolis (EEP), and bee pollen (EEBP) and its combination on L. monocytogenes number in wrapped salmon, salami, and cheese. Sterile fragments of propylene film were coated with solution containing CH, CH+EEP, CH+EEBP, and CH+EEP+EEBP. The coated film was applied directly after preparation (AP) after 10 days of storage from preparation (AS). L. monocytogenes strains isolated from cheese, salmon, and salami were transferred on adequate food type. ATCC 19111 reference strain was placed on all examined slices. Contaminated slices were wrapped in the coated film. The film adhered strictly to the slices surface and was left for 0, 1, 6, 12, and 24 hours. Antilisterial activity of AP film was additionally assessed during 15-day storage of products wrapped in the coated film. In conclusion, the chitosan-coated film exhibited antibacterial activity. Incorporation of EPP and EEBP enhanced this activity. The antilisterial activity depended on the type and concentration of solutions, the types of food, and the origin of strains. This study proved that the time that passed since the use of coated film for packing food was of great importance.

The impact of ethanol extract of propolis on biofilm forming by Proteus Mirabilis strains isolated from chronic wounds infections.

Alcoholic propolis extracts may be used to eliminate microbes in mucous membranes and skin inflammations and in wound infections. The aim of this study was an assessment of the ethanol extract of propolis (EEP) activity against biofilm formation by P. mirabilis. Six clinical strains of P. mirabilis isolated from patients with chronic wound infection, and one reference strain of P. mirabilis ATCC 29906 were used. Biofilm was formed in 96-well plate. In order to evaluate the effect of EEP at a concentration range of 1.56-100 mg/mL on the forming and mature biofilm, P. mirabilis cells were released by sonication. In this study the effectiveness of 25-100 mg/mL of EEP on the forming P. mirabilis biofilm and concentrations of 25-50 mg/mL of EEP on formed biofilm has been demonstrated. Our results suggest the possibility of using the EEP in treatment of chronic wound infection caused by P. mirabilis.