Evaluation of antioxidant activity of Clostridium (Clostridioides) difficile

Abstract

Aim: to develop and to evaluate a method for Clostridium (Clostridioides) difficile antioxidant activity (AOA) assessment via chemiluminescent (CL) analysis. Materials and methods: we investigated ten C. difficile strains, obtained from patients with antibiotic-associated diarrhea that were cultured for two days. AOA was assessed on the first and second day of cultivation by means of CL assay based on 2,2’-azo-bis (2-amidinopropane) dihydrochloride-luminol system. Results: our method for AOA estimation is characterized by high reproducibility and reliability (the average coefficient of variation between parallel samples is 2.0-18.2%, the calibration curve coefficient of determination is 80.5-89.4%). C. difficile AOA after the first day of cultivation is 6.95-9.93 units; it increases to 9.86-13.27 units after the second day (p <0.01). A negative correlation (η = -0.3, p <0.05) is shown between the initial AOA level and its growth rate during cultivation. Conclusion: we propose a simple and reliable method for C. difficile AOA assessment that is suitable for routine use in clinical bacteriology. Length of C. difficile culturing is associated with increase of its AOA.