Identification of Entamoeba Species in Diarrheal Samples Using Sequence Analysis and Nested Multiplex PCR.

Background: Among the many Entamoeba species that infect humans, only Entamoeba histolytica is considered pathogenic, being responsible for amoebiasis or amoebic dysentery.

Methods: Between June and October 2022, a total of 106 stool samples were collected from children under six years of age presenting with diarrhea at Paiji Hospital in the city of Paiji, Iraq. DNA was extracted from all stool specimens to detect the presence of parasitic organisms.

Results: Of the 106 fecal samples, 4 (3.7%) tested positive for Entamoeba spp. using an initial PCR amplification targeting approximately 900 bp of the 18S rRNA gene. Among these, only one sample tested positive for E. histolytica using a nested multiplex PCR assay. In this study, neither E. moshkovskii nor E. dispar was detected. Sequence analysis of the partial 18S rRNA gene revealed that 0.9% of samples were positive for E. histolytica, while 2.8% were positive for E. coli. The sequences were deposited in GenBank under the accession numbers OP868733.1 for E. histolytica and OP868730.1, OP868731.1, and OP868732.1 for E. coli.

Conclusion: Children were infected with different species of Entamoeba. Molecular methods are essential for distinguishing between Entamoeba species due to their significance in accurate diagnosis and appropriate treatment strategies.