Relationship of hemagglutination to other biological properties of serologically classified isolates of Escherichia coli.

The ability of 170 serologically classified strains of Escherichia coli to agglutinate human erythrocytes was examined. Erythrocytes of blood group A were more sensitive indicators of this property than were those of groups B or O. The predominant receptor was shown to be mannose containing; however, an additional receptor was found in two of nine strains studied. Natural mannose-like inhibitors were not found in unconcentrated urine obtained from 12 humans. Isolates from the urine or blood of patients with infections agglutinated erythrocytes significantly more frequently than did isolates from feces. Urine isolates of 10 common serogroups and isolates of less common serogroups did not differ in their ability to agglutinate erythrocytes. Among isolates from the urine of patients with infections, the ability to agglutinate erythrocytes did not correlate with either the serogroup of the strain or the clinical syndrome of the patient. Of the several other biological properties that were examined, only the production of colicins showed a significant association with the ability to agglutinate human erythrocytes.