Objective: The purpose of this study was to develop a clinically relevant animal model of DS to be able to characterize the host response and identify key fungal factors involved in pathogenesis.
Method: Recently, we developed a novel intraoral denture system for rodent research. This denture system consists of custom-fitted fixed and removable parts to allow repeated sampling and longitudinal studies. To establish DS, rats were inoculated with pelleted C. albicans, which resulted in sustained colonization of the denture and palate for 8 weeks post-inoculation.
Result: Biofilm formation on the denture was observed by week 4 and on the palate by week 6 post-inoculation. Rats were monitored for clinical signs of disease by assigning a clinical score after macroscopic examination of the palate tissue according to Newton’s method. By week 4 post-inoculation, the majority of inoculated rats with dentures exhibited a clinical score of 1 (pinpoint erythema). By week 6 and week 8 post-inoculation, increasing percentages of rats exhibited a clinical score of 2 (diffuse erythema/edema). Histological analysis of palate tissue demonstrated progressively increasing inflammatory cell recruitment throughout the infection. Palatal biofilm formation was commensurate with development of palatal erythema. In addition, a mutant strain deficient in a key regulator of biofilm formation (Dbcr1) was unable to induce clinical disease despite the fact that it colonized the palate and denture at levels equivalent to a wildtype strain.
Conclusion: We successfully developed a clinically relevant murine model of Candida-associated denture stomatitis, that shows a requirement for biofilm formation in pathogenesis.