Characterization of Partially Purified Fimbriae from Bacteroides intermedius Strain 17

Abstract

We characterized partially purified fimbriae from B. intermedius strain 17. Activity of the fimbriae was monitored by hemagglutination with rabbit erythrocytes. Lowering the pH of the fimbriae solution caused precipitation. Absorbance at 280nm of the supernatant reached a minimum at pH 4.5, suggesting that this was the isoelectric point. This pH value coincides with minimum hemagglutination activity. When the fimbriae solution was dialyzed against buffer at pH 4.0 or less, hemagglutination activity was reduced or lost. Fifty percent of hemagglutination activity was inhibited by heat treatment at 60-70℃ C for 10 minutes, and 94% at 100℃ for 10 minutes. The proteolytic enzymes trypsin, protease type IV and proteinase partially destroyed the hemagglutination activity. These results indicate that fimbriae are essentially proteinaceous in nature. Addition of D-glucosamine caused hemagglutination inhibition, suggesting that D-glucosamine may be associated with receptors for fimbriae.