Bactericidal Activity of Normal Serum Against Bacterial Cultures. II. Activity Against Escherichia coli Strains

Abstract

Resistance to bactericidal action of normal human serum of E. coli isolates from normal children and from those with diarrhea was determined. Results indicated that serum resistance did not provide a basis for differentiation of virulent and nonvirulent strains. Serum resistance was associated with the O-inagglutinability of the organisms. In addition, bactericidal action of normal human serum against E. coli was shown to be dependent upon natural antibodies of marked specificity.