Open Menu
Research Examines Role of Fungus in Dental Caries

Article Image

Written by Adam Zewe

A common oral fungus may contribute to the development of dental caries, according to research by Associate Professor Mary Ann Jabra-Rizk, PhD. Dr. Rizk and her students Khalid Mutawalli, DDS, an Advanced Education in General Dentistry resident, and Shariq Khan, DDS '17 recently published an article entitled "Streptococcus mutans, Candida albicans, and the Human Mouth: A Sticky Situation," in the journal PLOS Pathogens.

Their research highlights the interaction between the fungal species Candida albicans and the bacterium Streptococcus mutans. S. mutans causes dental caries, while C. albicans is a fungus that induces oral candidiasis or thrush. Both microbial species are normally found within the human mouth, yet their interactions have not been studied in great detail.

The researchers have shown that S. mutans attach strongly to the filamentous form (hyphae) of C. albicans as these species co-adhere to teeth. "It seems that both bugs survive very happily together. When they are together they attach, adhere and persist in much larger numbers than when they are alone," says Rizk. The fungus enables the colonization of a higher concentration of bacteria, which could impact the development and progression of dental caries. S. mutans excrete acid which wears away tooth enamel and causes dental caries. C. albicans also produces acid, which reduces the pH in the oral cavity and favors the growth of S. mutans.

In order to determine the clinical implications of this interaction, Rizk and her colleagues initiated a clinical study in collaboration with Professor Glenn Minah, DDS, PhD, and Clinical Assistant Professor Kuei-Ling Hsu, DDS, MS. The study evaluates pediatric patients for the co-presence of C. albicans and S. mutans. Preliminary findings have indicated a high level of C. albicans and S. mutans colonization in patients with dental caries. "Most dentists would not even associate C. albicans with dental caries. We want to raise awareness of this interaction as it could impact therapeutic measures," remarks Rizk.

The research team is also working with School of Pharmacy Professor Stephen Hoag, PhD, and his student, Heather Boyce, to develop a potential therapeutic agent. They are currently testing a novel antimicrobial, bioadhesive hydro-gel that inhibits S. mutans and C. albicans adherence to dental surfaces. If this topical, anti-microbial gel proves to be effective in clinical tests, it may lead to a patent and additional research funding.

More Information