Many children that are toddlers or preschool age may suffer from cavities or tooth decay which is aggressive and painful in children of such a young age.  Sometimes the tooth decay can be so severe in young children that they may need surgery to correct the problem.  According to a recent study, the dental caries and tooth decay that occur in young children are caused by a fungus and a bacterium that work together.  The results of this study are published in the journal Infection and Immunity.

The Infectants

The researchers in this study discovered that infections caused by S. mutans and C. albicans together significantly increased the number of cavities as well as their severity in rats.  According to corresponding author Hyun (Michel) Koo of the University of Pennsylvania School of Dental Medicine, “Our data will certainly open the way to test agents to prevent this disease, and even more intriguing, the possibility of preventing children from acquiring this infection.”

For the past 15 years, Koo has studied how microbes help form the biofilms, or plaque, that lead to the development of cavities and tooth decay.  The main agent in the formation of plaque is Streptococcus mutans but Koo and his researchers noticed that Candida albicans, a fungus commonly found on the cheek and tongue was also in the plaque in most instances of early childhood cavities and tooth decay.

“We were puzzled!” according to Koo.  “Candida usually does not associate with S. mutans, nor does it colonize teeth very effectively.”

How Infectants Combine

S. mutans causes plaque to form by reacting with sugars to create a sticky material called extracellular polysaccharide (EPS).  The same “exoenzyme” that causes this reaction also causes Candida to form its own sticky polymer that gives it the ability to stick to teeth and bind with S. mutans which it would not be able to do otherwise.

“The combination of the two organisms led to a greatly enhanced production of the glue-like polymer, drastically boosting the ability of the bacterium and the fungus to colonize the teeth, increasing the bulk of the biofilms and the density of the infection,” claims Koo.  “This represents a truly unique physical interaction where a bacterially-produced product attaches to and functions on the surface of an organism from another kingdom, converting this normally innocuous fungus into a fierce stimulator of cariogenic biofilm formation.”

These discoveries further support Koo’s hypothesis that early childhood cavities and tooth decay are the result of an infection caused by a fungus and a bacterium that are frequently exposed to sugar.