Investigation of Dientamoeba fragilis Frequency in Faecal Samples of Patients with Enterobius vermicularis Infection by Polymerase Chain Reaction

Objective:Dientamoeba fragilis (D. fragilis) is a flagellated protozoan with an amoeba-like morphology, located in the gastrointestinal tract. The hypothesis was that the parasite was transported by Enterobius vermicularis (E. vermicularis) eggs. This study aimed to determine the association of D. fragilis and E. vermicularis with the genotypes of the identified strain of D. fragilis. Results of trichrome staining were compared with those of polymerase chain reaction (PCR), which is widely used in the diagnosis of D. fragilis.Methods:A total of 391 samples were obtained. The stool and cellophane slide samples were sent together to the Parasitology Department Laboratory, Faculty of Medicine, Aydın Adnan Menderes University, between 1 October 2017 and 1 October 2018. Stool samples of all patients with E. vermicularis (n=74) and without E. vermicularis (n=74) infection were used. All samples were examined for the presence of D. fragilis by trichrome staining and PCR. The 18S ribosomal RNA region of D. fragilis isolates was sequenced. Demographic characteristics and clinical findings of the patients were evaluated.Results:D. fragilis was detected in 42 (28.37%) of 148 samples; 28 (66.6%) of them were detected in patients with E. vermicularis infection. The coexistence of two parasites was significant (p0.05).Conclusion:D. fragilis is frequently associated with E. vermicularis, so the presence of D. fragilis should be also considered in affected patients. The use of high-sensitivity molecular methods such as PCR is important in preventing false results.