Multilocus analysis reveals diversity in the genus [i]Tissierella[/i]: Description of [i]Tissierella carlieri[/i] sp nov in the new class [i]Tissierellia[/i] classis nov.

Corentine Alauzet (1) , Hélène Marchandin (2) , Pascal Courtin (3) , Francine Mory (1) , Ludovic Lemée (4) , Jean-Louis Pons (4) , Marie-Pierre Chapot-Chartier (3) , Alain Lozniewski (1) , Estelle Jumas-Bilak

1 SIMPA - Stress, Immunité, Pathogènes
2 Ecosym - Ecologie des systèmes marins côtiers
3 MICALIS - MICrobiologie de l'ALImentation au Service de la Santé
4 GRAM 1.0 - Groupe de Recherche sur les Antimicrobiens et les Micro-Organismes

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.

Mots clés: Tissierella; MLSA

Domaines: Sciences du Vivant [q-bio]

Corentine Alauzet, Hélène Marchandin, Pascal Courtin, Francine Mory, Ludovic Lemée, et al.. Multilocus analysis reveals diversity in the genus [i]Tissierella[/i]: Description of [i]Tissierella carlieri[/i] sp nov in the new class [i]Tissierellia[/i] classis nov.. Systematic and Applied Microbiology, 2014, 37 (1), pp.23-34. ⟨10.1016/j.syapm.2013.09.007⟩. ⟨hal-01204310⟩