title: Multilocus analysis reveals diversity in the genus Tissierella: description of Tissierella carlieri sp. nov. in the new class Tissierellia classis nov.
abstract: The genus Tissierella and its relatives Tepidimicrobium, Soehngenia and Sporanaerobacter comprise anaerobic Gram-positive bacilli classified along with Gram-positive cocci in a family with controversial placement designated as incertae sedis XI, in the phylum Firmicutes. We performed a top-down reappraisal of the taxonomy from the phylum to the species level within the genus Tissierella. Reconstruction of high-rank 16S rRNA gene-based phylogenies and their interpretation in a taxonomic purpose allowed defining Tissierellia classis nov. within the phylum Firmicutes while the frames of Tissierellales ord. nov. and Tissierellaceae fam. nov. have to be further strengthened. For species delineation in the genus Tissierella, we studied a population of clinical strains. Beside Tissierella praeacuta, a sub-population of five strains formed a clade in multilocus phylogenies (16S rRNA, cpn60, tpi, recA and spo0A genes). Data such as 16S rRNA gene similarity level, population structure, chromosome organization and murein type indicated that this clade corresponded to a novel species for which the name Tissierella carlieri sp. nov. is proposed, with type strain LBN 295(T)=AIP 268.01(T)=DSM 23816(T)=CCUG 60010(T). Such an approach, associating a phylogenetic reappraisal of high-level taxonomic ranks with weak taxonomic structure and a population study for genus and species delineation is needed to strengthen the taxonomic frame of incertae sedis groups in the phylum Firmicutes.
authors.affiliation: Université Lorraine, EA 7300 Stress Immunité Pathogènes, Faculté de Médecine, Vandoeuvre-les-Nancy, France. Electronic address: c.alauzet@chu-nancy.fr.
authors.forename: Corentine
authors.initials: C
authors.lastname: Alauzet
authors.affiliation: Université Montpellier 1, UMR 5119, Equipe Pathogènes et Environnements, Montpellier, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Marchandin
authors.affiliation: INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Courtin
authors.affiliation: Université Lorraine, EA 7300 Stress Immunité Pathogènes, Faculté de Médecine, Vandoeuvre-les-Nancy, France.
authors.forename: Francine
authors.initials: F
authors.lastname: Mory
authors.affiliation: Université de Rouen, EA 2656, Groupe de Recherche sur les Antimicrobiens et les Microorganismes (G.R.A.M.), Rouen, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Lemée
authors.affiliation: Université de Rouen, EA 2656, Groupe de Recherche sur les Antimicrobiens et les Microorganismes (G.R.A.M.), Rouen, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pons
authors.affiliation: INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Chapot-Chartier
authors.affiliation: Université Lorraine, EA 7300 Stress Immunité Pathogènes, Faculté de Médecine, Vandoeuvre-les-Nancy, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Lozniewski
authors.affiliation: Université Montpellier 1, UMR 5119, Equipe Pathogènes et Environnements, Montpellier, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Jumas-Bilak
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D006094:Gram-Positive Bacteria / Q000145:classification* / Q000235:genetics*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: Diversity; MLSA; Phylogeny; Taxonomy; Tissierella