title: Increased sampling reveals novel lineages of Entamoeba: consequences of genetic diversity and host specificity for taxonomy and molecular detection.
abstract: To expand the representation for phylogenetic analysis, ten additional complete Entamoeba small-subunit rRNA gene sequences were obtained from humans, non-human primates, cattle and a tortoise. For some novel sequences no corresponding morphological data were available, and we suggest that these organisms should be referred to as ribosomal lineages (RL) rather than being assigned species names at present. To investigate genetic diversity and host specificity of selected Entamoeba species, a total of 91 new partial small subunit rRNA gene sequences were obtained, including 49 from Entamoeba coli, 18 from Entamoeba polecki, and 17 from Entamoeba hartmanni. We propose a new nomenclature for significant variants within established Entamoeba species. Based on current data we propose that the uninucleated-cyst-producing Entamoeba infecting humans is called Entamoeba polecki and divided into four subtypes (ST1-ST4) and that Entamoeba coli is divided into two subtypes (ST1-ST2). New hosts for several species were detected and, while host specificity and genetic diversity of several species remain to be clarified, it is clear that previous reliance on cultivated material has given us a misleading and incomplete picture of variation within the genus Entamoeba.
authors.affiliation: Department of Microbiological Diagnostics, Statens Serum Institut, Artillerivej 3, DK-2300 Copenhagen S, Denmark.
authors.forename: C Rune
authors.initials: CR
authors.lastname: Stensvold
authors.forename: Marianne
authors.initials: M
authors.lastname: Lebbad
authors.forename: Emma L
authors.initials: EL
authors.lastname: Victory
authors.forename: Jaco J
authors.initials: JJ
authors.lastname: Verweij
authors.forename: Egbert
authors.initials: E
authors.lastname: Tannich
authors.forename: Mohammed
authors.initials: M
authors.lastname: Alfellani
authors.forename: Paulette
authors.initials: P
authors.lastname: Legarraga
authors.forename: C Graham
authors.initials: CG
authors.lastname: Clark
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004747:Entamoeba / Q000145:classification* / Q000235:genetics; D004749:Entamoebiasis / Q000469:parasitology; D014644:Genetic Variation / Q000235:genetics*; D058507:Host Specificity / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011323:Primates; D054679:Ribosome Subunits, Small / Q000235:genetics; D017422:Sequence Analysis, DNA; D014426:Turtles
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal