Extraction and properties of nonfimbrial mannose-resistant hemagglutinin from a urinary isolate of Escherichia coli

A mannose-resistant hemagglutinin (MRH) was extracted from an agar-grown urinary isolate of Escherichia coli (827) by heating the organisms at 65°C for 1 h. Both MRH and the organisms agglutinated erythrocytes from human (group A) but not from seven other animal species tested, but were devoid of any detectable fimbriae as examined by electron microscopy. MRH was sensitive to pronase or 100°C heating, but not to trypsin or periodate, could not be sedimented by ultracentrifugation 149,000 g, and passed the void volume of Sepharose-4B column. MRH inhibited the adherence of bacteria to tissue culture cells. The results suggest that E. coli human isolate produces mannose-resistant hemagglutinin, which is located on the cell surface in nonfimbrial form and probably mediates adherence of the bacteria to eukaryotic cells.