Casey Chen, D.D.S., Ph.D.

Casey Chen, D.D.S., Ph.D., Assistant Professor, Periodontology

Research Interests:
Genetic and phenotypic diversity of a periodontal pathogen Eikenella corrodens

E. corrodens is a putative periodontal pathogen which has not been rigorously studied. Although the bacterium is sometimes recovered at high levels in periodontal pockets of adult periodontitis and juvenile periodontitis patients, it is also an oral commensal found frequently in periodontally healthy subjects.

The objectives of the current research include
(1) to determine the genetic and phenotypic variations of E. corrodens from oral cavity of periodontally healthy and diseased subjects, and
(2) to evaluate the specific immune response against genetically distinct strains colonize concomitantly the same subjects.

The long term goal is to understand the pathogenic mechanisms of E. corrodens in order to treat periodontal disease caused by this bacterium.

PCR detection of periodontal pathogens in biological samples.

Among few hundred taxa of bacterial species in the human oral cavity, a limited number of species are believed to play significant roles in periodontal disease. The immediate goal of the research effort is to develop a highly sensitive and specific molecular detection method for each periodontal pathogen.

PCR detection methods have been developed and tested successfully for Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Treponema denticola, E. corrodens, Bacteroides forsythus, Helicobacter pylori.

The long term objective is to use these detection methods for large scale clinical microbiological investigations.

Evaluate the transmission of periodontal pathogens among host:

Arbitrarily-primed PCR DNA fingerprinting methods have been developed to distinguish distinct strains within the species of A. actinomycetemcomitans, P. gingivalis, E. corrodens, and B. forsythus. The objectives are
(1) to ascertain the genetic diversity of each bacterial species, and
(2) to determine the transmission of periodontal pathogens among human host.

The results from several studies have confirmed that periodontal pathogens are transmissible among cohabitants. Transmission may be influenced by the levels of bacteria in the donor's oral cavity, characteristics associated with individual bacterial species, and the existing microflora in the recipient's oral cavity.

The long term goal is to understand the critical factors in bacterial transmission in order to devise novel strategies for prevention and treatment of periodontal disease.

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Last revised: September 20, 1996 ... File: CHEN.html