Molecular subtyping of Blastocystis spp. using a new rDNA marker from the mitochondria-like organelle genome.
Blastocystis spp. are common anaerobic intestinal protozoa found in both human and animals. They are characterized by a high genetic diversity with at least 17 subtypes (STs) that have been described on the basis of a 600 bp 'barcoding region' from the 18S rDNA gene. However, analysis of the recently sequenced genome of a Blastocystis ST7 isolate (strain B) revealed the presence of multiple variable copies of the 18S rDNA gene, with 17 completely assembled copies. Comparison of the barcoding region from these 17 copies allowed us to classify the 18S rDNA sequences into 6 clusters, each cluster containing identical sequences. Surprisingly, 4 of these clusters had the highest homology with 18S rDNA sequences from 2 other Blastocystis ST7 isolates referred as QQ98-4 and H. These results suggest that the 18S rDNA gene is not the marker of choice to discriminate between strains within STs. In the present study, we identified a single-copy subtyping rDNA marker in the genome of the mitochondria-like organelles (MLOs). Using a partial sequence of the MLO rDNA, we successfully subtyped 66 isolates from both human and animals belonging to Blastocystis ST1 to ST10. Our results also indicate that this mitochondrial marker could be useful to detect co-infections by different isolates of a same ST.
CHU Clermont-Ferrand, Centre de Biologie, Laboratoire de Parasitologie-Mycologie, Hôpital G. Montpied, F-63003 Clermont-Ferrand, France.
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Poirier
Université Lille Nord de France, INSERM U1019, CNRS UMR 8204, Centre d'Infection et d'Immunité de Lille (CIIL), Institut Pasteur, Biologie et Diversité des Pathogènes Eucaryotes Emergents, F-59019, Lille, France.
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Meloni
CHU Clermont-Ferrand, Centre de Biologie, Laboratoire de Parasitologie-Mycologie, Hôpital G. Montpied, F-63003 Clermont-Ferrand, France.
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Nourrisson
Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, BP 10448, F-63000 Clermont-Ferrand, France.
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Wawrzyniak
Université Lille Nord de France, INSERM U1019, CNRS UMR 8204, Centre d'Infection et d'Immunité de Lille (CIIL), Institut Pasteur, Biologie et Diversité des Pathogènes Eucaryotes Emergents, F-59019, Lille, France.
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Viscogliosi
CHU Clermont-Ferrand, Centre de Biologie, Laboratoire de Parasitologie-Mycologie, Hôpital G. Montpied, F-63003 Clermont-Ferrand, France.
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Livrelli
Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, BP 10448, F-63000 Clermont-Ferrand, France.
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Delbac
D000818:Animals; D001483:Base Sequence; D016844:Blastocystis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016776:Blastocystis Infections / Q000469:parasitology*; D060085:Coinfection; D058893:DNA Barcoding, Taxonomic; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D018503:Genome, Protozoan / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D058889:Molecular Typing; D015388:Organelles / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D005819:Genetic Markers; D012337:RNA, Ribosomal, 18S