Microbial Pathogenesis of Oral Organisms

Specific inter-species adhesive interactions play an important role in the formation of bacterial biofilms in the oral cavity. These interactions are readily detected by in vitro coaggregation, a fluid-phase assay that is convenient for studies of individual strains. This group has developed an alternative approach that can be used to screen complex microbial mixtures - typically found in biofilm communities - for specific adhesins and cognate receptors, that mediate interbacterial adhesion. Currently, strains of oral early colonizing bacteria including Actinomyces naeslundii, Streptococcus oralis and S. gordonii are used as probes to isolate and identify microbial coadhesion partners within supragingival dental plaque. In addition, coadhesion partners among the oral indigenous microbiota for medically relevant bacteria such as the stomach pathogen Helicobacter pyloriare investigated. This bacterium has been suspected to either transiently or permanently colonize the oral cavity as an additional ecological niche which may have important implications for oral-oral transmission or reinfection of the stomach.

Another area of Dr. Ruhl's research is available at Saliva and Salivary Glands