Ex vivo decontamination of yeast-colonized dentures by iodine–thiocyanate complexes

Sarra Sebaa,1,2 Maxime Faltot,1 Sandra De Breucker,3 Zahia Boucherit-Otmani,2 Françoise Bafort,4 Jean-Paul Perraudin,5 Philippe Courtois1 1Laboratory of Physiology and Pharmacology, Université Libre de Bruxelles, Brussels, Belgium; 2Laboratory of Antibiotics and Antifungals: Physico-Chemistry, Synthesis and Biological Activity, University of Tlemcen, Tlemcen, Algeria; 3Department of Geriatrics, CUB – Hôpital Erasme, Brussels, Belgium; 4Integrated and Urban Plant Pathology Laboratory, Liège University, Gembloux, Belgium; 5Taradon Laboratory, Tubize, Belgium Introduction: Under well-defined experimental conditions, and in the presence of hydrogen peroxide, lactoperoxidase produces stable iodine–thiocyanate complexes that have antimicrobial properties. A novel process was developed to short circuit the consumption of hydrogen peroxide by microbial catalases by producing iodine–thiocyanate complexes prior to contact with microorganisms, with the aim of being able to decontaminate the ex vivo dentures colonized by yeasts. Materials and methods: Teabags containing lactoperoxidase adsorbed on inert clay beads were immersed for 1 minute in phosphate buffer solution (0.1 M pH 7.4) containing 5.2 mM potassium iodide, 1.2 mM potassium thiocyanate, and 5.5 mM hydrogen peroxide. After removing the adsorbed lactoperoxidase, the stability and efficacy of iodine–thiocyanate complexes for Candida-colonized denture decontamination were verified. Investigations were performed in vitro on Candida albicans ATCC 10231 and on clinical isolates from 46 dentures. A Candida plate count was performed after a 24-hour incubation at 37°C on Sabouraud–chloramphenicol or CHROMagar solid media; then, the yeast growth was evaluated in Sabouraud broth by turbidimetry and biofilm biomass by crystal violet staining. Results: In vitro tests demonstrated the effectiveness of the oxidant solution in sterilizing a suspension of 106 Candida cells per milliliter after a 5-minute incubation. A single ex vivo immersion of contaminated dentures in a solution of iodine–thiocyanate complexes led to a decrease of at least 1 log unit in the number of colony-forming units in 58.3% of the tested dentures, while immersing in water alone had no effect on denture colonization (significant X2: p = 0.0006). Conclusion: These data suggest a promising new strategy for decontamination of dentures. Keywords: biofilm, Candida, hygiene, lactoperoxidase, oral cavit

Prevalence and clinical significance of anti-lactoferrin autoantibodies in inflammatory bowel diseases and primary sclerosing cholangitis

Anti-neutrophil cytoplasmic antibodies (ANCA) are autoantibodies directed against cytoplasmic constituents of neutrophil granulocytes. Antibodies with specificity for proteinase 3 and myeloperoxidase are seromarkers for systemic vasculitides. ANCA with specificity for lactoferrin were described in patients with several idiopathic inflammatory diseases, such as the inflammatory bowel diseases and rheumatoid arthritis. However, the clinical significance of anti-lactoferrin autoantibodies is still unclear. In this study, we determined the clinical significance of anti-lactoferrin autoantibodies in sera from large groups of patients with ulcerative colitis (UC), Crohn's disease (CD), and primary sclerosing cholangitis (PSC). Antibodies to human lactoferrin were detected by ELISA and by immunoblotting, using an extract of sonicated neutrophils as antigen source. Autoantibodies to lactoferrin were found in 29% of patients with UC, 13% of patients with CD, and 22% of patients with PSC. In inflammatory bowel diseases, the presence of anti-lactoferrin antibodies was not related to treatment, disease activity, duration of disease, or disease extent. In PSC, the presence of autoantibodies to lactoferrin did not correlate with duration of disease or the presence of cirrhosis. However, patients with PSC and coexistent UC had significantly more frequently antibodies to lactoferrin than PSC patients without IBD. In conclusion, autoantibodies to lactoferrin are a common feature of inflammatory bowel diseases and PSC. However, the clinical significance of those autoantibodies is limited as they lack sensitivity and specificity for those disorders. Future research should address the pathophysiological role of anti-lactoferrin ANCA and the influence of anti-lactoferrin ANCA binding on the functional properties of the lactoferrin molecule