Natural Antibodies of Human Serum,Saliva,and Urine Reactive with Escherichia coli ∗

Abstract

Summary

Natural antibodies specific for Escherichia coli serotype 0126:B16:H were demonstrated in both the sera and secretions of normal volunteers by means of an indirect fluorescent antibody test (IFA). Each immunoglobulin class of bacterial specific antibody was identified by using fluorescein conjugated antisera for human γA, γG, and γM in the IFA test system. Both serum and concentrated saliva from normal donors contained bacterial specific antibodies representative of all three classes of immunoglobulin. The predominant bacterial specific antibody in the serum of seven donors was of the γG class. Concentrated saliva from five donors contained bacterial specific γA, γG and γM antibodies. The concentrated urine of five donors contained bacterial specific γA and γG antibodies, however, bacterial specific γM antibodies were detectable in only one urine specimen. Significant bacterial hemagglutination titers were obtained from all seven sera, three salivas, and one urine. Hemolysis titers paralleled hemagglutination titers in every case. Secretory γA from both saliva and urine was shown to be reactive with E. coli cells with specific antisera. E. coli cells sensitized with salivary and urinary γA preparations showed specific fluorescence when treated with antisera specific for either serum γA or secretory “piece.” However, cells sensitized with serum reacted only with γA specific antisera.