Saliva and Salivary Glands

The mineralized and tissue surfaces of the mouth are covered by a thin layer of adsorbed salivary proteins. Some of these adsorbed components serve as attachment sites for bacteria and, thus, enable them to get a foothold in the oral cavity by colonizing these surfaces. In many cases, highly specific recognition of cognate peptide or oligosaccharide motifs of salivary (glyco)proteins by corresponding adhesin molecules expressed on the bacterial surface is involved in the attachment of these microorganisms. But, whereas some bacterial adhesin molecules and their cognate binding motifs are meanwhile well characterized, the range of salivary proteins which carry these recognition motifs and mediate binding is not fully explored yet. It is essential to know about these mechanisms because those early steps of bacterial colonization set the stage for further build-up of oral microbial biofilms (dental plaque) that eventually harbor the potential for causing dental caries and periodontal disease.

We presently use proteomics approaches combined with far-Western bacterial overlay techniques to map salivary proteins that serve as binding sites for early colonizing commensal bacteria including oral actinomyces and viridans streptococci. The same approaches are also used to identify salivary proteins that are bound by medically relevant pathogens, exemplified by the stomach pathogen Helicobacter pylori, that have to pass the oral cavity on the way to their infection site.

Another area of Dr. Ruhl's research is available at Microbial Pathogenesis of Oral Organisms