Subtype distribution of Blastocystis spp. isolated from children in Eskisehir, Turkey.

Blastocystis spp. is the most common enteric protist found in human feces. The pathogenic role of Blastocystis remains controversial and it has been suggested that the symptomatology of Blastocystis is associated with its subtypes (ST). However, only few studies have investigated the relationship between the symptomatology and subtypes of Blastocystis in children. This study aimed to investigate the prevalence of Blastocystis in children aged 3 to 13years with or without gastrointestinal complaints and determine the distribution of the subtypes of Blastocystis. A total of 303 stool samples obtained from symptomatic (n=84) and asymptomatic (n=219) children were included in the study. The presence of Blastocystis was investigated using native-lugol examination, trichrome staining and real-time PCR method. Using the real-time PCR method, 115 samples were found positive for Blastocystis. Subtyping was successfully performed on 46 samples using sequenced-tagged site (STS) primers and PCR. The remaining 69 samples could not be subtyped. The most frequently detected subtype was ST3 (43.4%) followed by ST1 (26.1%), ST4 (10.9%) and ST2 (8.7%). The mixed subtypes were identified in five samples (10.9%) as; ST1+ST3 (n=3), ST1+ST2 (n=1) and ST2+ST3 (n=1). None of the samples had ST5, ST6 or ST7. No statistically significant difference was found between the symptomatic and asymptomatic groups in terms of the Blastocystis positivity and the distribution of subtypes (p>0.05). To our knowledge, this is the first study to investigate the subtype distribution of Blastocystis in children in Turkey and the results are in agreement with the related data available in Turkey.

Prevalence of microsporidia in healthy individuals and immunocompetent patients with acute and chronic diarrhea.

BACKGROUND: Previously published studies of microsporidial infections have primarily focused on immunodeficient or immunocompromised patients. Data regarding infections caused by this microorganism in immunocompetent subjects are lacking. In the present study, we investigated the prevalence of microsporidia in healthy individuals and immunocompetent patients with acute and chronic diarrhea. METHODS: The study included stool samples from 74 patients with acute diarrhea, 41 patients with chronic diarrhea, and 88 healthy volunteers. Slides were prepared after concentration with a formalin-ethyl acetate technique and were stained with modified trichrome, calcofluor white, and Uvitex 2B stains. The number of spores observed in each magnification field (×1000) was scored as follows: 1+, 1-10; 2+, 11-20; 3+, > 20. RESULTS: The prevalence of microsporidia was 27.0% in patients with acute diarrhea, 34.1% in patients with chronic diarrhea, and 45.5% in healthy volunteers. The parasite score was 1 + in all positive samples. The rate of microsporidia positivity was higher in solid stools (51.4%), and the rate of positivity increased with advancing age. CONCLUSION: Unexpectedly, a high prevalence of microsporidia was found in immunocompetent individuals in our region. There was no relationship between positivity for microsporidia and the presence of symptoms, due to higher rates both in solid stools and in healthy subjects. The parasite score was the same in all groups. Our results indicate that there is high exposure to microsporidia in immunocompetent subjects in our region. Natural reservoirs and environmental sources of microsporidia should be determined to design strategies for effective prevention of transmission.