Porphyromonas gingivalis, a bacterium that may play a major role in chronic and adult periodontitis, is the first oral disease–causing microbe whose genome has been sequenced completely, announced the National Institutes of Health on June 12.
The sequencing project was supported by the National Institute of Dental and Craniofacial Research, or NIDCR, and was carried out by scientists at The Institute for Genomic Research in Rockville, Md., in collaboration with The Forsythe Institute in Boston.
"P. gingivalis is one of the most intensely studied dental pathogens," said Dennis Mangan, Ph.D., chief of NIDCR’s Infectious Diseases and Immunity Branch. "There is a large cadre of researchers out there ready to use the sequence of data to identify the genetic mechanisms for the organism’s virulence and to develop better approaches for preventing or eradicating periodontitis."
With the genetic blueprint for P. gingivalis now available, dental researchers will have the opportunity to identify potential targets for periodontal vaccines and drug therapies. Currently, periodontitis is treated with surgery or scaling and root planing.
The genome sequence also will provide scientists with information about an organism from a major group of bacteria that has not been sequenced before: the bacteroides group of gram-negative anaerobes, which are associated with specific forms of periodontitis. The sequence, which contains 2.3 million DNA base pairs, can enhance scientists’ ability to find new gene targets for antibiotics that work on gram-negative anaerobes. These bacteria are naturally resistant to some antibiotics and are acquiring resistance to many others.
A prepublished version of the P. gingivalis genome is available at "www.tigr.org/tigr-scripts/CMR2/GenomePage3.spl?database=gpg". It has been provisionally annotated, and the products of most genes within the genome, including many responsible for virulence and growth, are listed.
