Study of hemagglutinating property of enteroinvasive Escherichia coli from various geographical locations.

Thirty-four strains of enteroinvasive Escherichia coli (EIEC) were examined for their ability to agglutinate erythrocytes from different animal species. All strains cultured in Casamino acid-yeast extract medium in the presence of 1 mM CaCl2 at 37 C for 16-22 hr induced maximal expression of hemagglutination (HA) of broad spectrum erythrocytes. The strongest HA was observed with guinea-pig erythrocytes followed by human (O type), rat, mouse, rabbit and sheep erythrocytes. All the strains failed to agglutinate chicken erythrocytes. HA was resistant to D-mannose, D-glucose, D-galactose, L-fucose, and D-fructose. Also HA was resistant to ethylene diamine tetraacetic acid (EDTA) and Na metaperiodic acid, an oxidizing agent. However, it was heat labile and completely inhibited by proteolytic enzymes such as proteinase K and trypsin, suggesting that the possible hemagglutinin of EIEC associated with the cell surface is a proteinaceous substance.