The relative abilities of selected oral bacterial species to attach to teeth and to oral mucosal surfaces will be studied using both in vitro and in vivo approaches. The influence of salivary and seorus components on bacterial attachment will be determined. Components studied will include those likely present in the acquired pellicle covering teeth as well as those free in oral fluids; special emphasis will be placed upon blood-group reactive mucins. Possible relationships between the composition of oral fluids as it influences bacterial attachment and susceptibility to infection will be determined. The influence of antibodies present in oral secretions on the adherence, colonization, antigenic composition and virulence of oral organisms will be assessed. The influence of various lectins, including those contained in certain foods, on the adherence and colonization of selected oral bacteria will be assessed. The roles of pili in colonization of Bacteroides relaninogenicus, and of motility for the colonization of Selenomonas sputigena and Campylobacter species will be evaluated.