IMMUNOFLUORESCENT DIAGNOSIS OF AMOEBIASIS

A dot enzyme-linked immunosorbent assay for detection of antibodies against Entamoeba histolytica

A visual micro-dot enzyme-linked immunosorbent assay (ELISA) based on detection of antibodies against soluble antigens of axenically grown cultures of Entamoeba histolytica is described. The antigen was spotted on a nitrocellulose sheet, the unsaturated sites blocked with bovine serum albumin (BSA) and incubated with 3-fold dilutions of patient sera followed by incubation with protein A conjugated to peroxidase. Enzymic activity was evidenced using the substrate 4-chloro-1-naphthol. A positive reaction produced a blue spot. The sensitivity of the assay was better and comparable to the indirect haemagglutination assay (IHA) and plate ELISA. The entire assay could be completed within 3 h. Antigen-loaded and pre-blocked nitrocellulose strips could be stored up to 3 months at room temperature and 37 degrees C.

[Serological diagnosis of human amebiasis using the fluorescent antibody technic]

Images

Diagnostic value of liver function tests and Entamoeba histolytica antibody studies in East Africans

Liver function tests and Entamoeba histolytica (E.H.) antibody titres have been studied in a variety of tropical and liver diseases. Patients with hepatic amoebiasis had a raised E.H. antibody titre and tended to have a low pseudocholinesterase activity. In two cases of amoebic liver abscess, which were treated by aspiration and emetine, there was a remarkable drop in the E.H. antibody titre. In a number of other hepatic and tropical conditions the E.H. antibody titre was not significantly raised and the liver function tests were typical of the various conditions studied.