Abstract
BACKGROUND: Blastocystis is one of the most common intestinal parasites in humans and various animals worldwide. Few studies are available regarding the genetic characterization of Blastocystis infections in humans in China. METHODS: In the present study, 609 fecal samples were collected from two- to six-year-old kindergarten children in southern Xinjiang and were examined by polymerase chain reaction (PCR). RESULTS: The infection rate of Blastocystis was 14.3% (87/609); no significant difference was observed among counties and between sexes. Blastocystis subtypes ST1 (n = 38), ST2 (n = 8), and ST3 (n = 41) were identified by sequence analysis of the small subunit ribosomal RNA gene. Genetic polymorphisms were observed at the intra-subtype level, including seven variations for ST1 (ST1A to ST1G), four for ST2 (ST2A to ST2D), and two for ST3 (ST3A and ST3B); with ST1F and ST2B being new variations. CONCLUSIONS: ST1 and ST3 are the two common Blastocystis subtypes in the study area. More extensive studies in both humans and animals in different regions are needed to better characterize the transmission of Blastocystis.