BACKGROUND

The oral cavity is comprised of many surfaces, each coated with a plethora of bacteria, the proverbial bacterial biofilm (see figure below). Based on both culture and culture-independent molecular methods using sequence analysis of 16S rRNA genes, we and others have identified most of the predominant bacterial species in the oral cavity. Collectively speaking, there are about 550 oral bacterial species, of which about 60% have not yet been cultivated in vitro. These “uncultivables” are often termed phylotypes.

Figure 1: Bacterial biofilm on tooth surface

In order to make definitive bacterial associations with oral health and disease states, the microbial profiles of large numbers of clinical samples must be determined. 16S rRNA-based DNA probes have been designed and validated. We have developed the Human Oral Microbe Identification Microarray, or HOMIM, in order to examine complex oral microbial diversity in a single hybridization. This high throughput technology will allow the simultaneous detection about 300 bacterial species, including the “uncultivables”.

 

References

1. Aas JA, Barbuto SM, Alpagot T, Olsen I, Dewhirst FE, Paster BJ. Subgingival plaque microbiota in HIV+ patients. J Clin Periodontal 2006; doi: 10.1111/j.1600-051X.2006.01034.x.

2. Aas JA, Paster BJ, Stokes LN, Olsen I, Dewhirst FE. Defining the normal bacterial flora of the oral cavity. J Clin Microbiol 2005;43:5721-5732.

3. Kazor CE, Mitchell PM, Lee AM, Stokes LN, Loesche WJ, Dewhirst FE, Paster BJ. Diversity of bacterial populations on the tongue dorsum in halitosis and in health. J Clin Microbiol 2003;41:558-563.

4. Paster BJ, Boches SK, Galvin JL, Ericson RE, Lau CN, Levanos VA, Sahasrabudhe A, Dewhirst FE. Bacterial diversity in human subgingival plaque. J Bacteriol 2001;183:3770-3783.

5. Paster BJ, Olsen I, Aas JA, Dewhirst FE. The breadth of bacterial diversity in the human periodontal pocket and other oral sites. Periodontology 2000;2006;42:80-87.