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

Abstract

(1) Boiled broth cultures and sterile Seitz filtrates thereof of Escherichia coli serogroups 055 and 0111 render red blood cells of man and rabbit specifically agglutinable by the homologous group-specific antisera. Unheated cultures, and nitrates are only slightly effective. Trypsinized red blood cells are somewhat better agglutinated than non-tryp-sinized cells. (2) The significance of the findings regarding the indirect bacterial hemagglutination test is discussed with particular reference to the phenomenon of bacterial inagglutinability.