Detection and differentiation of Entamoeba histolytica and Entamoeba dispar from clinical samples by PCR and Enzyme-linked immunosorbent assay

Abstract

The epidemiology of amoebiasis is not clearly defined throughout the African continent since many of the studies conducted on the disease have used methods that are neither specific nor sensitive. The aim of this study was to isolate and identify Entamoeba species from stool samples of patients attending selected health care centers in Zimbabwe and Cameroon. A total of 183 stool specimens were screened from urban areas (Yaoundé, Cameroon and Harare, Zimbabwe) and from rural area (Mutoko, Zimbabwe). From 57 samples collected in Cameroon, twenty strains were isolated by culture; and isoenzyme analysis revealed 7 (12%) E. histolytica and 13 (23%) E. dispar. The PCR amplification gave similar results as the isoenzyme analysis with a correlation of 100%; two (4%) samples were coinfected with both E. histolytica and E. dispar. From eighteen (25%) strains isolated by culture from 48 samples collected in Harare, the isoenzyme analysis revealed 5(10%) E. histolytica and 13 (27%) E. dispar. The ELISA and PCR methods confirmed these results with a correlation of 100%. Twenty-six (33%) E. histolytica were found from 78 stool samples from the Mutoko rural area in Zimbabwe. The antigen detection and the PCR had the same specificity for E. histolytica (100%) and the ELISA method had a sensitivity of 93% compared to isoenzyme analysis. The use of specific methods, particularly the ELISA, which is rapid and easy to perform, could be an important tool for the diagnosis of E. histolytica infections and hence the control of the disease in the region where the disease seems to be endemic.


Journal of Tropical Microbiology and Biotechnology Vol. 1 (1) 2005: 3-9