HEMAGGLUTINATION PROPERTIES OF ENTEROCOCCUS

In total, 86 enterococcal strains including representatives of most of the described species were tested for the ability to agglutinate huma n, sheep, and rabbit erythrocytes. Five strains did not react with any of the erythrocytes tested, and 81 (94.2%) strains agglutinated only rabbit erythrocytes. The hemagglutination titers ranged from 2 to 64. Loss of the hemagglutination activity was observed when rabbit erythro cytes were treated with trypsin or neuraminidase. Trypsin treatment of the bacterial suspensions also caused loss of the agglutination abili ty. On the other hand, heat treatment of bacterial suspensions increas ed the efficiency of the interactions, and higher titers were obtained , Assays for inhibition of hemagglutination were performed with alpha- D-fucose, alpha-D-galactose, beta-D-galactose, D-glucose, N-acetyl-gal actosamine, N-acetyl-glucosamine, N-acetylneuraminic acid, N-acetylneu raminic acid-lactose, and fetuin. Only fetuin was able to inhibit the hemagglutination reactions, The results showed that hemagglutination p roperties are common to the different enterococcal species tested. The y also suggest that enterococci possess hemagglutinins of proteic and non-proteic nature that are involved in the attachment to sialic acid- containing receptors on the surface of rabbit erythrocytes.