Molecular Characterization and Serological Cut-off (Copro-Antigen ELISA) of Entamoeba Histolytica and Giardia Lamblia-Khartoum State

Abstract

This study aimed to determine the molecular characterization and serological cut-off (Copro-Antigen ELISA) of E. histolytica and G. lamblia in Khartoum State. A cross- sectional study was conducted in period between August, 2014 to August, 2017. Epidemiological and parasitological data were obtained and recorded. 300 stool samples were collected from all participants, (100 infected with E. histolytica, 100 infected with G. lamblia and 100 healthy individuals as control group). All samples were diagnosed by formal ether technique as gold standard method. The results showed that, the point prevalence of E. histolytica and G. lamblia during data collection were (5.8, 7.2) respectively. The sensitivity and specificity of Copro antigen ELISA and PCR techniques against microscopy were (88%, 49%) for E. histolytica and (90, 42%) for giardiasis respectively. The clinical cut off Copro ELISA among Sudanese population of E. histolytica and G. lamblia of case study and control group were (0.98±0.20), (0.49±0.25) and (0.13±0.01), (0.07±0.08) respectively. The higher prevalence rate 45% occurred at eastern part of Khartoum State (P value= 0.04) among males group 55% at the age of 21-30 years (43.8%) (P value < 0.01). The study showed that, 80% of the infection occured as acute phase of the disease at P < 0.01 level. The study indicated that, the bioinformatics analysis results in 80-100% similarity together with variant alteration of 18s gene of E. histolytica EH strains and GDH gene for G. lamblia on NCBI with the following sequences ID: KT253454.1, KT253453.1, KJ870202.1, and: JF918446.1, JF918441.1 JF968194.1 respectively. 41 (84%) out of 49 positive PCR samples were single infection of E. histolytica; while 8 (16 %) out of 49 samples were co infection with E. dispar. When RFLP genotyping was performed, the most prevalent strain for G. lamblia were group AI (81%), group AII (14%) and group B(5%) respectively at (P value =0.01). The association of symptoms related to G. lamblia assemblage was found to be (81%) with Group AI sub genotype as virulence strain with acute phase of the disease, while (5%) of Group BIII sub genotype were strongly related to chronic diarrhea with very low prevalence rate at P value < 0.01.