Direct Molecular Detection and Phylogenetic Tree Analysis of Gastrointestinal Protozoan Parasites (Giardia lamblia, Entamoeba his-tolytica, Cryptosporidium parvum) from Diarrhea Infection in Kut City of Iraq: A Short Communication

  • D.K. Kadhim Department of Anatomy and Biology, Faculty of Medicine, University of Wasit, Wasit, Iraq
  • D.A. Alzubaidi Wasit Education Directorate, Wasit, Iraq
Keywords: Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum, Phylogeny, Diarrhea, 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 69 patients with diarrhea and then transferred to laboratory. Protozoan parasites were evaluated by Polymerase Chain Reaction (PCR) and phylogenetic tree analysis. Small subunit 18S rRNA region was amplified in the sizes of 514 bp, 409 bp, and 507 pb for G. lamblia, E. histolytica, and C. parvum, respectively.

Results: The results of phylogenetic tree analysis showed that G. lamblia had 99% identity to G. lamblia with accession number of DQ157272.1 (and total genetic changes of 0.002%); E. histolytica also had 99% identity to E. histolytica with accession number of GQ423748.1 (total genetic changes of 0.0005%); and C. parvum had 99% identity to C. parvum with accession number of AJ539197.1 (total genetic changes of 0.05%).

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.