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Published on: April 25, 2025
Investigation of intestinal parasites by conventional and molecular methods in children with gastrointestinal system
Merve Özkan-Ahmetoğlu1, Filiz Demirel2, Medine Ayşin Taşar3
1Department of Medical Microbiology, Ankara Training and Research Hospital, Health Science University, Ankara, Türkiye.
Insights
Intestinal parasites like Blastocystis spp. and Dientamoeba fragilis are common in children with gastrointestinal issues. Further research is needed to clarify their role as pathogens versus commensals.
Area of Science:
- Medical Parasitology
- Pediatric Gastroenterology
- Molecular Diagnostics
Background:
- Intestinal parasitic infections pose a significant global health burden, particularly affecting children in rural areas.
- Gastrointestinal complaints in children are often linked to parasitic infections, necessitating accurate diagnostic methods.
Purpose of the Study:
- To determine the prevalence of intestinal parasites, specifically Blastocystis spp. and Dientamoeba fragilis, in pediatric patients with gastrointestinal complaints.
- To compare the prevalence of these parasites in symptomatic children versus healthy controls.
- To identify subtypes of Blastocystis spp. using molecular techniques.
Main Methods:
- Stool samples analyzed using conventional methods (microscopy, staining) and molecular methods (real-time PCR, Sanger sequencing).
- Study included 100 pediatric patients with gastrointestinal complaints and 50 healthy children.
- Detection of Blastocystis spp. and D. fragilis via real-time PCR; Blastocystis spp. subtyping via Sanger sequencing.
Main Results:
- Conventional methods detected parasites in 12% of patients and 1% of controls.
- Real-time PCR identified Blastocystis spp. in 14% of patients and 8% of controls; D. fragilis in 17% of patients and 8% of controls.
- No significant difference in prevalence for Blastocystis spp. or D. fragilis between patient and control groups; ST1 was the most common Blastocystis subtype.
Conclusions:
- Blastocystis spp. and D. fragilis are highly prevalent in pediatric patients experiencing gastrointestinal complaints.
- The pathogenic or commensal role of these protists in gastrointestinal disorders requires further investigation through case-control studies.
- Understanding the impact on intestinal microbiota is crucial for both symptomatic and healthy individuals.
Abstract:
Intestinal parasitic infections are a global health problem that causes morbidity and mortality, especially in children living in rural areas. In this study, stool samples of pediatric patients with gastrointestinal complaints were examined by conventional and molecular methods to determine the prevalence of intestinal parasites. A total of 100 pediatric patients with gastrointestinal complaints and 50 healthy children were included in the study. Stool samples were collected from each child and examined by direct microscopic examination (native-Lugol method), formol-ethyl acetate concentration technique, Kinyoun's acid-fast staining, and Wheatley trichrome staining methods. Real-time PCR was used for the detection of Blastocystis spp. and D. fragilis in the stool samples. Sanger sequencing was used to identify Blastocystis spp. subtypes. One or more intestinal parasites were found in 12% (n = 100) of the patient group and 1% (n = 50) of the control group using conventional techniques. By using real-time PCR, Blastocystis spp. was discovered in 14% (14/100) of the patient group and 8% (4/50) of the control group. There was no significant difference in the frequency of Blastocystis spp. between the two groups. The most prevalent Blastocystis subtype was ST1 and the most frequent allele was a2 among the samples successfully amplified and sequenced. D. fragilis was detected in 17% (17/100) of the patient group and 8% (4/50) of the control group by real-time PCR. The prevalence of D. fragilis was not significantly different between the patient and control groups, as well. Blastocystis spp. and D. fragilis were found in high prevalence in pediatric patients with gastrointestinal complaints in this study. Although the role of these protists as a pathogen in humans is still controversial, it is supposed to the presence of the parasites are associated with gastrointestinal disorders such as diarrhea, abdominal pain, nausea, and vomiting. More case-control studies are needed to understand the pathogenic or commensal role of these parasites on the intestinal microbiota, especially in both patients with gastrointestinal disorders and healthy individuals.
