[Influence of various anions and biological macromolecules on bacterial aggregation in vitro]

Abstract

The effects of various anions on experimental bacterial aggregation has been studied with Streptococcus mutans OMZ 175 and Actinomyces viscosus X1, using an experimental system, based on the measurement of optical density in an aqueous polyethyleneglycol medium. Monovolent anions (acétate, chloride and fluoride) and sulphate had no effects on bacterial aggregation in salivary concentrations. However carbonate, mono and dihydrogenophosphates gave an important aggregation in relatively small saline concentrations. The study of the aggregation of Strep. mutans OMZ 175, grown in presence of sucrose for 12 to 96 hours, showed an increased aggregation of the micro-organims up to 24 hours. For longer incubation times, aggregation decreased. Finally a calcium precipitable salivary glycoprotein, at small concentrations, gave a bacterial aggregation of about 25% and may be important in dental plaque formation.