Inter-kingdom Interaction Mediated Synergistic Pathogenesis in Gingivitis

Objectives: Both bacteria and fungi co-exist in oral cavity and often cause similar oral infectious diseases. This study is to explore the possible correlation between inter-kingdom interactions mediated synergistic pathogenesis for gingivitis of orthodontic patients.
Methods: Our previous studies showed the in vitro interaction of a Gram negative bacterium Fusobacterium nucleatum and a fungal pathogen Candida albicans. In this study, the clinical and morphological approaches were used to validate the F. nucleatum and C. albicans interaction in vivo and their possible connections with enhanced pathogenesis. Clinical samples from orthodontic patients with healthy gum and severe gingivitis were collected and quantitatively analyzed for the presence of C. albicans and F. nucleatum in correlation with gingivitis individually and coordinately. Samples with the co-existence of C. albicans and F. nucleatum are further examined for their direct interaction in vivo with multiplex FISH.
Results: Higher prevalence and co-existence rate of F. nucleatum and C. albicans was found in the severe gingivitis group. The in vivo co-localization of F. nucleatum and C. albicans is ongoing.
Conclusions: Inter-kingdom interaction of F. nucleatum and C. albicans may play a role in mediating synergistic pathogenesis for gingivitis in orthodontic patients.