Effects of Zn on Clostridioides Difficile Sporulation

Clostridioides difficile (C. difficile) is a Gram-positive, anerobic, spore-forming and toxin-producing bacterial pathogen that causes C. difficile infection (CDI), the most common healthcare-associated infection in USA. C. difficile. Formation of dormant spores is one of the main virulence factors of this multi-drug resistant organism. Pathogenesis of CDI is mediated by the disruption of gut microbiota due to factors such as antibiotic uses. But how minerals impact CDI is mostly unknown. Previous studies indicated that high levels of the mineral Zinc exacerbate CDI whereas Zn supplementation decreased the recurrence of CDI. However, the effect of Zinc on C.difficile sporulation is unexplored. Based on the data available, we hypothesized that Zinc has crucial effect on the sporulation of C.difficile. In this study, we investigated the sporulation efficiency of the C. difficile strain R20291 (a hypervirulent strain) under various concentrations of Zinc Chloride at 24 hours and 48 hours. Preliminary results revealed that under the Zinc Chloride concentrations 75 uM and 150 uM, C.difficile produced spores at higher efficiencies than the control C. difficile cultures free of zinc supplementation (7.3% and 17.8% increase in sporulation efficiency, respectively, compared to the control at 48 hours). However, under the Zinc concentration 200 uM, the sporulation efficiency of C.difficile was decreased (23% reduction of sporulation efficiency compared to the control at 48 hours). Based on these preliminary observations, we suggest that the mineral Zinc concentration plays an important role in C.difficile sporulation, in a concentration-dependent manner. Additional experiments are being conducted to substantiate these preliminary observations