D.K. Kadhim - Department of Anatomy and Biology, Faculty of Medicine, University of Wasit, Wasit, Iraq
D.A. Alzubaidi - Wasit Education Directorate, Wasit, Iraq

Background: The intestinal tract of human can be infected by protozoan parasites. In this short communication, the stool samples were collected from patients with diarrhea referred to Kut hospital, Iraq, and then the parasites (Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum) were considered for molecular identification. Methods: Stool samples were collected from ۶۹ patients with diarrhea and then transferred to laboratory. Protozoan parasites were evaluated by Polymerase Chain Reaction (PCR) and phylogenetic tree analysis. Small subunit ۱۸S rRNA region was amplified in the sizes of ۵۱۴ bp, ۴۰۹ bp, and ۵۰۷ pb for G. lamblia, E. histolytica, and C. parvum, respectively. Results: The results of phylogenetic tree analysis showed that G. lamblia had ۹۹% identity to G. lamblia with accession number of DQ۱۵۷۲۷۲.۱ (and total genetic changes of ۰.۰۰۲%); E. histolytica also had ۹۹% identity to E. histolytica with accession number of GQ۴۲۳۷۴۸.۱ (total genetic changes of ۰.۰۰۰۵%); and C. parvum had ۹۹% identity to C. parvum with accession number of AJ۵۳۹۱۹۷.۱ (total genetic changes of ۰.۰۵%). Conclusion: Gastrointestinal symptoms in the individuals with the studied protozoan parasites can be diagnosed directly by molecular detection and phylogenetic tree analysis with satisfying results. As well as, it can be utilized like a target for therapeutic intervention for these enteric protozoans. DOI: ۱۰.۱۸۵۰۲/jfqhc.۹.۴.۱۱۳۷۸

Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum, Phylogeny, Diarrhea, Iraq