title: Subtype Distribution of Blastocystis in Communities along the Chao Phraya River, Thailand.
abstract: Blastocystis is a common zoonotic enteric protozoan that has been classified into 17 distinct subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distributions of Blastocystis in villagers living along the Chao Phraya River, Ayutthaya Province, Thailand, and to assess the risk of zoonotic infection. In total, 220 stool samples were collected, and DNA was extracted. PCR and sequencing were performed with primers targeting the small-subunit ribosomal RNA (SSU rRNA) genes. Blastocystis was present in 5.9% (13/220) of samples, and ST3 (5.0%; 11/220) was the predominant subtype, followed by ST2 (0.45%; 1/220) and ST6 (0.45%; 1/220). Phylogenetic trees were constructed with the maximum-likelihood method based on the Hasegawa-Kishino-Yano + G + I model, neighbor-joining, and maximum parsimony methods. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. All the sequences of the Blastocystis-positive samples (KU051524-KU051536) were closely related to those from animals (pig, cattle, and chicken), indicating a zoonotic risk. Therefore, the villagers require proper health education, especially regarding the prevention of parasitic infection, to improve their personal hygiene and community health. Further studies are required to investigate the Blastocystis STs in the animals living in these villages.
authors.affiliation: Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Attakorn
authors.initials: A
authors.lastname: Palasuwan
authors.affiliation: Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Duangdao
authors.initials: D
authors.lastname: Palasuwan
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Aongart
authors.initials: A
authors.lastname: Mahittikorn
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Rachatawan
authors.initials: R
authors.lastname: Chiabchalard
authors.affiliation: Faculty of Sciences, School of Life Sciences, University of Technology, Sydney, Australia.
authors.forename: Valery
authors.initials: V
authors.lastname: Combes
authors.affiliation: Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Supaluk
authors.initials: S
authors.lastname: Popruk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016844:Blastocystis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D016776:Blastocystis Infections / Q000453:epidemiology* / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D048028:DNA, Algal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005243:Feces / Q000469:parasitology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D015995:Prevalence; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D045483:Rivers; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
chemical_list: D048028:DNA, Algal; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S
keywords: Blastocystis; Chao Phraya River; Thailand; subtype; zoonotic risk