title: ITS1 sequence variabilities correlate with 18S rDNA sequence types in the genus Acanthamoeba (Protozoa: Amoebozoa).
abstract: The subgenus classification of the ubiquitously spread and potentially pathogenic acanthamoebae still poses a great challenge. Fifteen 18S rDNA sequence types (T1-T15) have been established, but the vast majority of isolates fall into sequence type T4, and so far, there is no means to reliably differentiate within T4. In this study, the first internal transcribed spacer (ITS1), a more variable region than the 18S rRNA gene, was sequenced, and the sequences of 15 different Acanthamoeba isolates were compared to reveal if ITS1 sequence variability correlates with 18S rDNA sequence typing and if the ITS1 sequencing allows a differentiation within T4. It was shown that the variability in ITS1 is tenfold higher than in the 18S rDNA, and that ITS1 clusters correlate with the 18S rDNA clusters and thus corroborate the Acanthamoeba sequence type system. Moreover, high sequence dissimilarities and distinctive microsatellite patterns could enable a more detailed differentiation within T4.
authors.affiliation: Department of Medical Parasitology, Clinical Institute of Hygiene and Medical Microbiology, Medical University of Vienna, Kinderspitalgasse 15, 1095 Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Köhsler
authors.forename: Brigitte
authors.initials: B
authors.lastname: Leitner
authors.forename: Marion
authors.initials: M
authors.lastname: Blaschitz
authors.forename: Rolf
authors.initials: R
authors.lastname: Michel
authors.forename: Horst
authors.initials: H
authors.lastname: Aspöck
authors.forename: Julia
authors.initials: J
authors.lastname: Walochnik
mesh_terms: D000048:Acanthamoeba / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D000818:Animals; D016000:Cluster Analysis; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D020459:Genes, rRNA; D014644:Genetic Variation; D006801:Humans; D051379:Mice; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012337:RNA, Ribosomal, 18S