April 18, 2006
Shortly after brushing our teeth, it starts again. Certain oral bacteria attach anew to the clean enamel and serve as the foundation upon which other bacteria touch down and develop into a larger, ecologically diverse oral biofilm. This everyday fact of oral microbiology has led some dental researchers to try and characterize these initial colonizers as potential therapeutic targets to control the formation of the oral biofilm and prevent tooth decay. In the April issue of the journal Applied and Environmental Microbiology, NIDCR scientists suggest these first bacterial responders may be more variable than previously thought. Using molecular techniques that cast a much wider investigative net than previous studies, the scientists discovered most of the early colonizers varied strikingly from person to person. In fact, more than two thirds of the bacterial species identified were unique to each of the three people in the study. However, the scientists found 10 bacterial species were common in all three people, suggesting possible core strains that are highly adaptable and which are common members of early biofilms. The scientists also noted shifts over four to eight hours in the proportion of bacterial species present in the early biofilm. These changes may indicate that in some early biofilms, only a subset of the early colonizers predominate over time.