Haemagglutination of bovine erythrocytes by enterotoxigenic E. coli (ETEC) of O 6 serogroup: evidence for glycoconjugate receptor heterogeneity.

Five strains of enterotoxigenic E. coli (ETEC) producing fimbrial antigens which cause mannose-resistant haemagglutination of bovine erythrocytes (MRHA+bov) were selected among a collection of ETEC strains of the O 6 serogroup with CFA/II-like fimbrial haemagglutinins for this study. Our findings indicate that the MRHA reaction of bovine erythrocytes with these five strains reacted differently in a reproducible manner with erythrocytes from different bovine individuals. However, the complex heterogeneity of bovine erythrocyte antigens has not made it possible to relate specific blood group antigen(s) with the MRHA reaction with these different MRHA+bov ETEC strains. We conclude that bovine erythrocytes from individual animals must be tested with a battery of ETEC strains causing MRHA+bov before use in screening for CFA/II-like haemagglutinins.