Different binding specificities of P. mirabilis compared to E. coli.

The target cell specificities of P. mirabilis and E. coli strains were compared using human urinary tract epithelial cells and erythrocytes from human, guinea pig, sheep, ox and horse blood. P. mirabilis strains agglutinated the erythrocytes both in mannose-resistant and mannose-sensitive patterns. No relation was, however, found between hemagglutination and adhesion to uroepithelial cells. This is in contrast to E. coli where uroepithelial cell attachment is paralleled by mannose-resistant agglutination o human erythrocytes. The difference in receptor recognition between P, mirabilis and E. coli was further indicated by the fact that P. mirabilis strains attaching to human uroepithelial cells did not agglutinate guinea pig red cells coated with globotetraosylceramide, acting as a receptor for E. coli on human uroepithelial cells erythrocytes.