title: Update on Acanthamoeba jacobsi genotype T15, including full-length 18S rDNA molecular phylogeny.
abstract: Free-living amoebae of the genus Acanthamoeba are worldwide present in natural and artificial environments, and are also clinically important, as causative agents of diseases in humans and other animals. Acanthamoeba comprises several species, historically assigned to one of the three groups based on their cyst morphology, but presently recognized as at least 20 genotypes (T1-T20) on the basis of their nuclear 18S ribosomal RNA (rRNA) gene (18S rDNA) sequences. While strain identification may usually be achieved targeting short (<500 bp) 18S ribosomal DNA (rDNA) fragments, the use of full-length gene sequences (>2200 bp) is necessary for correct genotype description and reliable molecular phylogenetic inference. The genotype T15, corresponding to Acanthamoeba jacobsi, is the only genotype described on the basis of partial sequences (~1500 bp). While this feature does not prevent the correct identification of the strains, having only partial sequences renders the genotype T15 not completely defined and may furthermore affect its position in the Acanthamoeba molecular tree. Here, we complete this gap, by obtaining full-length 18S rDNA sequences from eight A. jacobsi strains, genotype T15. Morphologies and physiological features of isolated strains are reported. Molecular phylogeny based on full 18S rDNA confirms some previous suggestions for a genetic link between T15 and T13, T16, and T19, with T19 as sister-group to T15.
authors.affiliation: CHLAREAS Chlamydia Research Association, 12 Rue du Maconnais, 54500, Vandoeuvre-lès-Nancy, France. corsaro@gmx.fr.
authors.forename: Daniele
authors.identifier: http://orcid.org/0000-0002-1754-1546
authors.initials: D
authors.lastname: Corsaro
authors.affiliation: Molecular Parasitology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Köhsler
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Montalbano Di Filippo
authors.affiliation: CHLAREAS Chlamydia Research Association, 12 Rue du Maconnais, 54500, Vandoeuvre-lès-Nancy, France.|TREDI Research Department, Faculty of Medecine, Technopôle Nancy-Brabois, 9 Avenue de la Fôret de Haye, B.P. 184, 54505, Vandoeuvre-lès-Nancy, France.
authors.forename: Danielle
authors.initials: D
authors.lastname: Venditti
authors.affiliation: Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Monno
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Di Cave
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Berrilli
authors.affiliation: Molecular Parasitology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Walochnik
mesh_terms: D000048:Acanthamoeba / Q000235:genetics*; D000818:Animals; D016054:DNA, Protozoan / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D005838:Genotype; D006801:Humans; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics*
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S
keywords: Acanthamoeba; Acanthamoeba T15; Acanthamoeba jacobsi; Group I intron; Group III acanthamoebae