Demonstration of Escherichia coli 055 and 0111 Antigens by Means of Hemagglutination Test.

Abstract

Expts. were carried out to determine whether red cells adsorb the 0 antigen of E. coli serogroups 0111 and 055. Boiled broth cultures and sterile Seitz filtrates thereof E. coli sero-groups 055 and 0111 render red blood cells of man and rabbit specifically agglutinable by the homologous group-specific antisera. Unheated cultures and filtrates are only slightly effective. Trypsinized red blood cells are somewhat better agglutinated than non-trypsinized cells. The significance of the findings regarding the indirect bacterial hemaggluttnation test is discussed with particular reference to the phenomenon of bacterial inagglutinability.