Amebiasis in Nicaragua: class specific serum antibody responses.

With the aid of the indirect hemagglutination (IHA) test and IgG ELISA the antibody profile against E. histolytica in León, Nicaragua was investigated in 562 sera from individuals belonging to various age groups. The highest reactivity was invariably recorded in the age group 6-15 years where 48% were seropositive.

Identification of a parasite-specific cytoplasmic 67 kDa Entamoeba histolytica antigen recognized by patient sera and monoclonal antibodies.

To avoid false positive reactions in tests for anti-ameba antibodies, we wanted to identify parasite-specific component(s). Amebiasis patient sera recognized an antigen of 67 kDa by immunoblotting in an active E. histolytica fraction obtained by ion exchange chromatography.

Antibodies against Entamoeba histolytica antigens in sera from individuals with amoebiasis of different localization.

The over-all contents and relative component composition of Entamoeba histolytica antigens in abscess fluids and in extracts of cultured amoebae, strain NIH 200, were studied by antigen-catching EIA, counterimmunoelectrophoresis (CIE) and immunoblotting techniques. The antigen contents of liver abscess fluid were determined semiquantitatively by the antigen-catching EIA in four cases. In CIE against a standard "diagnostic" extract of cultured amoebae, sera from cases of acute amoebic liver abscess gave 4-5 precipitation lines while sera from cases of intestinal amoebiasis gave at most 3 lines.