Chairman Robert Burne and oral biology department at UF College of Dentistry take a bite out of bad bacteria

Eew! That sticky goo growing on your teeth is plaque. But to Robert A. Burne, Ph.D., chairman of oral biology at the UF College of Dentistry, it’s biofilm and it’s beautiful.

A microscopic view of biofilm reveals surrealistic strands of bacteria draped in graceful loops and serpentines, forming great, clustered colonies on the porous tooth surface that can erode tooth enamel and invade gingival tissues and cells to cause periodontal disease.

The typical human mouth supports a whole host of bacteria — all living, reproducing and dying by the millions inside our mouths, for the most part without our knowledge. Most of these bacterial strains have lived in harmony with our species for hundreds of thousands of years, coexisting inside our mouths with a minimum of fuss.

That was until our diets changed, and we began feeding the bacteria too much sugar.

Now some strains of sugar-pumped bacteria, most notably Streptococcus mutans, reproduce helter-skelter inside our mouths, gobbling up the glucose from the foods we chew and excreting corrosive lactic acid onto our tooth enamel. Before you know it, you’ve got a full-blown case of dental caries, and the chemical balance inside your mouth favors the reproduction of the bad bugs over the benign.

Burne, recruited from the University of Rochester School of Medicine and Dentistry in 2001, is working to develop a genetically engineered strain of bacteria that will defeat the bad bugs like S. mutans. His research has shown a certain strain of common oral bacteria produces ammonia and it beats the bad bugs by changing the pH balance inside the mouth. There is evidence that the elevated pH balance may even encourage remineralization of the tooth enamel. Burne’s idea is to develop a super strain of this ammonia-producing bacteria that could be introduced into a person’s mouth very early, providing a lifetime of protection against tooth decay.

Burne is not alone in the battle against bad bacteria. He leads a department of talented researchers dedicated to exploring the molecular biology of oral diseases. The department’s research focuses on microbiology and immunology, and its research faculty is, per capita, among the most productive in the nation in garnering National Institutes of Health research award funding — increasing from $3 million in NIH funding in 2000-01 to more than $9 million today, a meteoric increase of more than 200 percent.

To help the college establish a blueprint for further expansion, Burne penned a winning NIH Research Infrastructure Planning Grant proposal, funded this fall. The Research Infrastructure Planning Grant will facilitate a comprehensive inventory of all research under way in the college, the amount of square footage devoted to research activities, research equipment and personnel, as well as multidisciplinary partnerships and collaborative opportunities for college researchers within the university and the UF Health Science Center.

“I think this college is extremely strong in basic science research, and it has been very successful over the last few years,” Burne said. “Yet there is a tremendous amount of untapped potential, especially in periodontal research, pain research and clinical translational research. The infrastructure planning grant will enable us to identify our strengths and weaknesses in terms of potential.”

This introspective process will demand the college make some hard decisions about where future investments in research should be made. So far, everyone seems to agree that clinical translational research would enable greater alignment with National Institute of Dental and Craniofacial Research goals of continuing the “struggle” against two of the most common infectious diseases — dental caries and periodontal diseases — and the elimination of oral and pharyngeal malignancies, craniofacial birth defects and developmental disorders, acute and chronic orofacial pain, and other conditions that threaten oral health.

“Clinical translational research and periodontal research are areas in which we are not as strong as some other institutions, but there’s a good foundation in place here on which to build,” Burne said.

That foundation includes the college’s broad patient base to support both areas of research. Burne believes a few key recruitments of faculty to write the program grants and do the research would be a big step in the right direction.

Burne said another of the college’s greatest strengths is its ability to establish collaborative relationships with multidisciplinary researchers at the health center.

“I think it’s easy to recruit people to Florida when you recruit in areas where people can see immediate linkages,” Burne said. “For instance, there are a lot of logical applications in dentistry for areas like biomemetics (tissue engineering), involving everything from implants to stem cell biology. We have a great stem cell group conducting research in the Health Science Center and a brand new biomedical engineering program.”

Collaborative efforts among dental scientists and researchers in other areas of the Health Science Center have already proven fruitful. Several important patents have resulted from these research partnerships, including a technology called IVIAT, which identifies proteins expressed by disease-causing bacteria during the infection process. IVIAT was initially developed to study infections of Actinobacillus actinomycetemcomitans in juvenile periodontitis patients. It is also licensed to researchers outside the university for use in the study of a wider array of viral, fungal, parasitic and other bacterial infections, including that of Pseudomonas aeruginosa in cystic fibrosis patients.

The department of oral biology’s Center for Molecular Microbiology supports collaboration among infectious disease researchers and clinicians from the colleges of Dentistry, Medicine and Veterinary Medicine. The focus of the center is to explore the mechanisms of microbial pathogenesis and invent novel technologies for the discovery of new antimicrobial targets, vaccines and diagnostics.

One of the Center for Molecular Microbiology’s exciting developments is the recently patented technology for the treatment of malignant tumors, based on the findings of dental researchers Ann Progulske-Fox, Ph.D., and Emil Kozarov, Ph.D. They discovered that enzymes produced by the oral bacterium Porphyromonas gingivalis have the ability to degrade the bonds that hold certain types of human cells together. The patented technology using the enzyme can be applied to selectively destroy newly formed blood vessels that feed tumors, while at the same time loosening the cellular structure of the tumor to allow greater access for current therapeutics. They also are investigating the potential of applying the technology to other diseases that require the growth of new blood vessels, such as macular degeneration, psoriasis and rheumatoid arthritis.

Other research partnerships exist between the college faculty and researchers at the university’s McKnight Brain Institute, medicine’s department of rheumotology, the Center for Orphaned Autoimmune Disorders, and the UF Shands Cancer Center.

Another strength of the college’s research is its diversity and quality. State-of-the-art techniques are used to study the molecular genetics and physiology of bacterial pathogenesis; the physiology, pharmacology and genetics of exocrine secretion; basic function and modulation of the mucosal immune system; autoimmunity; and the interaction of pathogenic organisms with host cells.

Burne predicts the research infrastructure planning assessment will also identify molecular and cellular immunology as areas in need of recruitment, but he defers final judgment to the internal and external advisory committees that will be formed as part of the assessment.

“The internal and external advisory committees are going to have a lot of work to do. But one of the things that surprised me was that, when you tally up all of the numbers, early feedback is not out of proportion to what is realistic,” Burne said.

It is very realistic to expect the college will continue its expansion of research activities, building on the synergy created by collaborations with other Health Science Center researchers and the scientific community’s growing arsenal of hi-tech tools. These research efforts will lead to improved clinical treatments for a broad spectrum of patient maladies in both dentistry and medicine.

“We have been successful largely because of a small number of highly productive people. We now have a golden opportunity to go to the next level and become the type of institution that is conducting state-of-the-art research of the type that the National Institute of Dental and Craniofacial Research wants done in dental schools,” Burne said.