Oral Biology Research Profiles

 

G.H.W. Bowden
M.Phil., Ph.D. (London).
Professor Emeritus

bowden@cc.umanitoba.ca

 

The basis for all studies and the major interest is microbial ecology of the oral cavity. Bacteria are involved in diseases in the oral cavity and the oral flora is one of the most complex associated with tissue surfaces in the human.

Bacteria respond to changes in the environment and it is known that specific changes in the oral environment promote caries and periodontal disease. Understanding the relationship between environment, bacteria and disease is therefore fundamental to explaining the aetiology of oral disease.

The approaches to determining these relationships cover several areas in oral microbiology, including modification of growth conditions, determining bacterial characteristics, measuring antigenic relatedness between bacteria, bacterial taxonomy, bacterial adaptation to environmental conditions and agents such as mercury and fluoride, and most recently the extent of clonal diversity among oral bacteria.

A main thrust for our studies has been to develop methods for the examination of biofilms of oral bacteria and this is likely to expand in the future. In other studies an attempt is being made to understand the normal flora, in particular Actinomyces and Prevotella and the host antibody response to the normal flora. In certain instances clinical studies are undertaken to confirm or reinforce hypotheses that have been based on in vitro observations. Clinical staff collaborate in the studies in vivo and our laboratories have considerable experience in analysing samples from the oral cavity.

Studies are funded by The Medical Research Council Canada.

Relevant publications

  • Bowden, G.H.; Nolette, N.; McKee, A.S. & Hamilton, I.R. (1991). The stability of outer- membrane protein and antigen profiles of a strain of Bacteroides intermedius grown in continuous culture at different pH and growth rates. Can. J. Microbiol. 37: 368-376.
  • Bowden, G.H., Johnson, J. and Schachtele, C. (1993). Characterization of Actinomyces with genomic DNA fingerprints and rRNA gene probes. J. Dent. Res. 72, 1171-79.
  • Lyttle, H.A. and Bowden, G.H. (1993) The level of mercury in human dental plaque and interaction in vitro between biofilms of Streptococcus mutans and dental amalgam. J. Dent. Res. 72, 1320-24.
  • Putnins, E.E. and Bowden, G.H. (1993) Antigenic relationships between strains of Actinomyces naeslunii genospecies 1 and 2 and the animal species A. Howelii, A. denticolens and A. slackii. J. Dent. Res. 72, 1374-85.
  • Milnes, A.R., Bowden, G.H., Gates, D. and Tate, R. (1993). Normal microbiota on the teeth of Preschool children. Micro. Ecol. Hlth. Dis 6, 213-27.
  • Li, Y.H. and Bowden, G.H. (1994) Characteristics of accumulation of oral gram positive bacteria on mucin conditioned glass surfaces in a model system. Oral Microbiol. Immunol. 9, 1-11.
  • Cole, M.F., Evans, M., Fitzsimmons, S., Johnson, J., Pearce, C., Shheridan, M.J., Wientzen, R. and Bowden, G.H. (1994). Pioneer oral streptococci produce immunoglobin A1 protease. Inf. Immunol. 62, 2165-68.
  • Li, Y.H. and Bowden, G.H. (1994). The effect of environmental pH and fluoride from the substratum on the development of biofilms of selected oral bacteria. J. Dent. Res. (in press.)