title: Genetic diversity of blastocystis in livestock and zoo animals.
abstract: Blastocystis is a common unicellular anaerobic eukaryote that inhabits the large intestine of many animals worldwide, including humans. The finding of Blastocystis in faeces in mammals and birds has led to proposals of zoonotic potential and that these hosts may be the source of many human infections. Blastocystis is, however, a genetically diverse complex of many distinct organisms (termed subtypes; STs), and sampling to date has been limited, both geographically and in the range of hosts studied. In order to expand our understanding of host specificity of Blastocystis STs, 557 samples were examined from various non-primate animal hosts and from a variety of different countries in Africa, Asia and Europe. STs were identified using 'barcoding' of the small subunit rRNA gene using DNA extracted either from culture or directly from faeces. The host and geographic range of several STs has thereby been greatly expanded and the evidence suggests that livestock is not a major contributor to human infection. Two new STs were detected among the barcode sequences obtained; for these, and for three others where the data were incomplete, the corresponding genes were fully sequenced and phylogenetic analysis was undertaken.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Alfellani
authors.forename: Derya
authors.initials: D
authors.lastname: Taner-Mulla
authors.forename: Alison S
authors.initials: AS
authors.lastname: Jacob
authors.forename: Christine Atim
authors.initials: CA
authors.lastname: Imeede
authors.forename: Hisao
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: C Rune
authors.initials: CR
authors.lastname: Stensvold
authors.forename: C Graham
authors.initials: CG
authors.lastname: Clark
mesh_terms: D000818:Animals; D000836:Animals, Zoo / Q000469:parasitology*; D016844:Blastocystis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D004197:Disease Reservoirs / Q000469:parasitology*; D014644:Genetic Variation; D058507:Host Specificity; D006801:Humans; D058751:Livestock / Q000469:parasitology*; D008969:Molecular Sequence Data; D010802:Phylogeny
keywords: Blastocystis; epidemiology; livestock; phylogeny; subtype.