The Distribution of Blastocystis Subtypes among School-aged Children in Mugla, Turkey

Background: Blastocystis is a common protozoon that inhabits human intestinal tract and has a worldwide distribution. This study aimed to determine subtype (ST) distribution of Blastocystis among school-aged children in a western city of Turkey between Mar and Jun 2014. Methods: This cross-sectional study was conducted among primary school children in Mugla between Mar and Jun 2014. Overall, 468 stool samples from children were examined by direct microscopy and inoculated into Jones medium. Blastocystis partial small subunit ribosomal RNA gene (SSU-rDNA) was amplified and sequenced from culture positive isolates. Subtypes were determined according to closest or exact match at GenBank and Blastocystis ST (18S) database. Results: The positive rate of Blastocystis was 7.4% (n=35) with xenic in-vitro culture (XIVC). The subtypes could be identified for 33 (94.2%) isolates; 12 (34.2%) were ST3, 11 (31.4%) were ST1, 9 (25.7%) were ST2, one was (2.8%) ST7. No relationship was found between Blastocystis infected and non-infected cases in terms of gastrointestinal symptoms. Additionally, none of the possible risk factors was related to Blastocystis infection. Conclusion: Subtypes in children was similar to those reported in most of the studies that found ST3 as the most common subtype.