Peptoniphilus coxii sp. nov. and Peptoniphilus tyrrelliae sp. nov. isolated from human clinical infections

Two groups of previously undescribed anaerobic, gram-positive cocci recovered from human clinical infections were characterized using phenotypic and molecular genotypic methods. Comparative genotypic analysis showed that the strains within each of these two groups were homogeneous within the group and that each group was unique within the genus Peptoniphilus. The first group is most closely related to Peptoniphilus ivorii and the second group to Peptoniphilus harei. Based on these findings we propose two novel species, Peptoniphilus coxii sp. nov. and Peptoniphilus tyrrelliae sp. nov. The type strains are P. coxii sp. nov., RMA 16757^T (= JCM 16892^T = CCUG 59622^T = ATCC BAA-2106^T) and P. tyrrelliae sp. nov., RMA 19911^T (= JCM 16893^T = CCUG 59621^T = ATCC BAA-2105^T).     

Mycoplasma nasistruthionis sp. nov. and Mycoplasma struthionis sp. nov. isolated from ostriches with respiratory disease

Twelve Mycoplasma (M.) strains isolated from the nose, the trachea, and the lung of ostriches (Struthio camelus) displaying respiratory disease were investigated. Analysis of 16S rRNA gene sequences placed five of these strains within the M. synoviae cluster, and seven strains within the M. hominis cluster of genus Mycoplasma, which was further confirmed by analyses of the 16S-23S rRNA intergenic spacer region, and partial rpoB gene and amino acid sequences. Genomic information as well as phenotypic features obtained by matrix-assisted laser desorption ionization time of flight (MALDI-ToF) mass spectrometry analysis and serological reactions indicated that the strains examined are representatives of two hitherto unclassified species of genus Mycoplasma, for which the names Mycoplasma nasistruthionis sp. nov., with type strain 2F1A^T (= ATCC BAA-1893^T = DSM 22456^T), and Mycoplasma struthionis sp. nov., with type strain 237IA^T (= ATCC BAA-1890^T = DSM 22453^T), are proposed.     

Salinispora pacifica sp. nov., an actinomycete from marine sediments

A polyphasic analysis was carried out to clarify the taxonomic status of four marine actinomycete strains that share a phylogenetic relationship and phenotypic characteristics with the genus Salinispora. These strains formed a distinct lineage within the Salinispora 16S rRNA and gyrB trees and were found to possess a range of phenotypic properties and DNA:DNA hybridization values that distinguished them from the type strains of the two validly named species in this genus, Salinispora tropica (CNB-440^T, ATCC BAA-916^T) and Salinispora arenicola (CNH-643^T, ATCC BAA-917^T). The combined genotypic and phenotypic data support this conclusion. It is proposed that the strains be designated as Salinispora pacifica sp. nov., the type strain of which is CNR-114^T (DSMZ YYYYT = KACC 17160^T).     

Klebsiella michiganensis sp. nov., A New Bacterium Isolated from a Tooth Brush Holder

Isolate W14^T recovered from a household tooth brush holder was found to be gram-negative, a facultative anaerobic, non-motile, capsulated, and a non-endospore-forming straight rod. Based on phylogenetic analysis with 16S rRNA gene sequence, isolate W14^T was affiliated to the genus Klebsiella. The closest phylogenetic relative was K. oxytoca with 99 % similarity in the 16S rRNA gene sequence. The major whole-cell fatty acids were C_16:0 (31.23 %), C_18:1ω6c/C_18:1ω7c (21.10 %), and C_16:1ω7c/C_16:1ω6c (19.05 %). The sequence similarities of isolate W14^T based on rpoB, gyrA, and gyrB were 97, 98, and 98 % with K. oxytoca, and 97, 93, and 90 % with K. mobilis (=Enterobacter aerogenes), respectively. The ribotyping pattern showed a 0.46 similarity with K. oxytoca ATCC 13182^T and 0.24 with K. mobilis ATCC 13048^T. The DNA G+C content of isolate W14^T was 54.6 mol%. The DNA–DNA relatedness was 55.7 % with K. oxytoca ATCC 13182^T. Using the identification technology of MALDI-TOF mass spectrometry, the top matches for this isolate were K. oxytoca ATCC 13182^T (Match Factor Score 1.998) and K. mobilis (Score 1.797). On the basis of phenotypic, biochemical, chemotaxonomic, and molecular studies, isolate W14^T could be differentiated from other members of the genus Klebsiella including K. mobilis. Therefore, it is proposed that isolate W14^T (=ATCC BAA-2403^T=DSM 25444^T) should be classified as the type strain of a novel species of the genus Klebsiella, K. michiganensis sp. nov.     

Pseudomonas sivasensis sp. nov. isolated from farm fisheries in Turkey

A study of 91 isolates from fish farms in Turkey showed that isolates P7^T, P11, P24b, P29, P72, P73 and P158 belonged to the genus Pseudomonas according to 16S rRNA nucleotide sequence analysis. The analysis of the sequences of the RNA polymerase sigma factor gene (rpoD) located these strains in the Pseudomonas fluorescens lineage of species within the P. fluorescens subgroup, close to the cluster composed of the species Pseudomonas grimontii, Pseudomonas marginalis and Pseudomonas panacis. Based on similarities in the 16S rRNA and rpoD gene sequences of three previously isolated strains from other origins (CCUG 57209, CCUG 62357 and W5.2-93) linked them to the same cluster. A polyphasic taxonomic approach including phenotypic characterization, fatty acid composition, and multilocus sequence analysis, together with whole-cell MALDI-TOF data, corroborated this assumption. The genome G+C mol% contents were 59.48 and 59.71, respectively. The average nucleotide indices based on BLAST analysis and the genome-to-genome distance calculation for the P7^T and CCUG 57209 strains with their closest relative, P. grimontii, were 88.16–88.29% and 38.10–38.20%, respectively. These data confirm that isolates P7^T, P11, P24b, P29, P72, P73, P158, CCUG 57209, CCUG 62357 and W5.2-93 represent a new species for which the name Pseudomonas sivasensis is proposed, with P7^T as a type strain (=CCUG 74260^T= and CECT30107^T).     

Paenibacillus taohuashanense sp. nov., a nitrogen-fixing species isolated from rhizosphere soil of the root of Caragana kansuensis Pojark

A nitrogen-fixing bacterium, designated strain gs65^T, was isolated from a rhizosphere soil sample of Caragana kansuensis Pojark. Phylogenetic analysis based on a fragment of the nifH gene and the full-length 16S rRNA gene sequence revealed that strain gs65^T is a member of the genus Paenibacillus. High levels of 16S rRNA gene similarity were found between strain gs65^T and Paenibacillus borealis DSM 13188^T (97.5 %), Paenibacillus odorifer ATCC BAA-93^T (97.3 %), Paenibacillus durus DSM 1735^T (97.0 %) and Paenibacillus sophorae DSM23020^T (96.9 %). Levels of 16S rRNA gene sequence similarity between strain gs65^T and the type strains of other recognized members of the genus Paenibacillus were below 97.0 %. Levels of DNA–DNA relatedness between strain gs65^T and P. borealis DSM 13188^T, P. odorifer ATCC BAA-93^T (97.3 %), P. durus DSM 1735^T and P. sophorae DSM23020^T were 35.9, 38.0, 34.2 and 35.5 % respectively. The DNA G+C content of strain gs65^T was determined to be 51.6 mol%. The major fatty acids were found to be iso-C_14:0, anteiso-C_15:0 and iso-C_16:0. On the basis of its phenotypic characteristics and levels of DNA–DNA hybridization, strain gs65^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus taohuashanense sp. nov. is proposed. The type strain is gs65^T (=CGMCC 1.12175^T = DSM 25809^T).     

Geobacillus galactosidasius sp. nov., a new thermophilic galactosidase-producing bacterium isolated from compost

Two thermophilic spore-forming strains, with optimum growth temperature at 70 °C, were isolated from compost of the “Experimental System of Composting” (Teora, Avellino, Italy). A phylogenetic analysis based on 16S rRNA gene sequences showed that these organisms represented a new species of the genus Geobacillus. Based on polyphasic taxonomic data the strains represented a novel species for which the name Geobacillus galactosidasius sp. nov. is proposed. The type strain is CF1B^T (= ATCC BAA-1450^T = DSM 18751^T).     

Anaerofustis stercorihominis gen. nov., sp. nov., from human feces

Phenotypic and phylogenetic studies were performed on an unidentified Gram-positive, strictly anaerobic, non-spore-forming, rod-shaped bacterium isolated from human feces. The organism was catalase-negative, resistant to 20% bile, produced acetic and butyric acids as end products of glucose metabolism, and possessed a G+C content of approximately 70 mol%. Comparative 16S rRNA gene sequencing demonstrated that the unidentified bacterium was a member of the Clostridium sub-phylum of the Gram-positive bacteria, and formed a loose association with rRNA cluster XV. Sequence divergence values of 12% or greater were observed between the unidentified bacterium and all other recognized species within this and related rRNA clusters. Treeing analysis showed the unknown anaerobe formed a deep line branching near to the base of rRNA cluster XV and phylogenetically represents a hitherto unknown taxon, distinct from Acetobacterium, Eubacterium sensu stricto, Pseudoramibacter and other related organisms. Based on both phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from feces be classified in a new genus Anaerofustis, as Anaerofustis stercorihominis sp. nov. The type strain of Anaerofustis stercorihominis is ATCC BAA-858(T)=CCUG 47767(T).     

Prescottia equi gen. nov., comb. nov.: a new home for an old pathogen

The taxonomic status of Rhodococcus equi, originally isolated from foal specimens, has been the subject of discussion for a number of years. The chequered history of the taxon has prompted this polyphasic analysis of R. equi strains, close members of the genus Rhodococcus and representatives of other genera classified in the order Corynebacteriales, to establish the taxonomic position of this taxon. Thirty one R. equi strains, including the type strain, were examined for genotypic and numerical taxonomic properties. The resultant data are consistent with their classification in the order Corynebacteriales but the R. equi strains formed a distinct phyletic clade away from representatives of other members of the genus Rhodococcus in the 16S rRNA gene tree. Representatives of this clade shared their highest pairwise 16S rRNA gene sequence similarities with the type strain of Rhodococcus kunmingensis (95.2–98.1 %). However, the R. equi taxon was readily distinguished from R. kunmingensis and from the other members of the order Corynebacteriales using a combination of genotypic, chemotypic and phenotypic properties. On the basis of these data the R. equi strains are considered to represent a new genus. The name proposed for this taxon is Prescottia gen. nov., with Prescottia equi comb. nov. as the type species containing the type strain, C 7^T (= ATCC 25729^T = ATCC 6939^T = CCUG 892^T = CIP 54.72^T = DSM 20307^T = HAMBI 2061^T = NBRC 14956^T = JCM 1311^T = JCM 3209^T = LMG 18452^T = NBRC 101255^T = NCTC 1621^T = NRRL B-16538^T = VKM Ac-953^T).     

Cetobacterium somerae sp. nov. from human feces and emended description of the genus Cetobacterium

Phenorypic and phylogenetic studies were performed on four isolates of an unidentified gram-negative, microaerotolerant, non-spore-forming, rod-shaped bacterium isolated from the feces of children. The unknown organism was bile resistant and produced acetic acid as the major end product of metabolism of peptides and carbohydrates. It possessed a low DNA G + C content of 31 mol %. Comparative 16S rRNA gene sequencing demonstrated that the four isolates were phylogenetically identical (100% 16S rRNA sequence similarity) and represent a hitherto unknown sub-line within the genus Cetobacterium. The novel bacterium displayed approximately 5% sequence divergence with Cetobacterium ceti, and can be readily distinguished from the latter by physiological and biochemical criteria. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown fecal bacterium be classified in the genus Cetobacterium, as Cetobacterium somerae sp. nov. The proposed type strain of Cetobacterium somerae is WAL 14325(T) (ATCC BAA-474(T) = CCUG 46254T).     

Temperature and nutrient induced responses of Lake Fryxell sulfate-reducing prokaryotes and description of Desulfovibrio lacusfryxellense, sp. nov., a pervasive, cold-active, sulfate-reducing bacterium from Lake Fryxell, Antarctica

The effects of temperature and carbon substrate availability on the stimulation of sulfate reduction by indigenous populations of sulfate-reducing prokaryotes (SRP) in permanently ice-covered Lake Fryxell, Antarctica were investigated. Psychrophilic and halotolerant, lactate-degrading SRP showed significant metabolic activity throughout all sampled depths of the water column, suggesting that such organisms, possibly of marine origin, may be key contributors to carbon and sulfur cycling in Lake Fryxell. Planktonic and benthic strains of lactate-oxidizing sulfate-reducing bacteria (SRB) were isolated from samples of various depths of the anoxic water column and from surficial sediments. Phylogenetic analyses of 16S rRNA gene sequences placed the Fryxell sulfate-reducer (FSR) strains within the Deltaproteobacteria and showed them to be most closely related to the Arctic marine species of SRB Desulfovibrio frigidus and Desulfovibrio ferrireducens. Based on phylogenetic and phenotypic differences between the Antarctic FSR strains and related species of the genus Desulfovibrio, strain FSRs^T (=DSM 23315^T =ATCC BAA-2083^T) is proposed as the type strain of a novel species of cold-active SRB, Desulfovibrio lacusfryxellense, sp. nov.     

Defluviimonas denitrificans gen. nov., sp. nov., and Pararhodobacter aggregans gen. nov., sp. nov., non-phototrophic Rhodobacteraceae from the biofilter of a marine aquaculture

Three Gram-negative bacterial strains were isolated from the biofilter of a recirculating marine aquaculture. They were non-pigmented rods, mesophiles, moderately halophilic, and showed chemo-organoheterotrophic growth on various sugars, fatty acids, and amino acids, with oxygen as electron acceptor; strains D9-3^T and D11-58 were in addition able to denitrify. Phototrophic or fermentative growth could not be demonstrated. Phylogenetic analysis of the 16S rRNA gene sequences placed D9-3^T and D11-58, and D1-19^T on two distinct branches within the alpha-3 proteobacterial Rhodobacteraceae, affiliated with, but clearly separate from, the genera Rhodobacter, Rhodovulum, and Rhodobaca. Based on morphological, physiological, and 16S rRNA-based phylogenetic characteristics, the isolated strains are proposed as new species of two novel genera, Defluviimonas denitrificans gen. nov., sp. nov. (type strain D9-3^T = DSM 18921^T = ATCC BAA-1447^T; additional strain D11-58 = DSM19039 = ATCC BAA-1448) and Pararhodobacter aggregans gen. nov., sp. nov (type strain D1-19^T = DSM 18938^T = ATCC BAA-1446^T).     

Dysgonomonas hofstadii sp. nov., isolated from a human clinical source

A Gram-negative staining, facultative anaerobic, cocco-bacillus-shaped organism was isolated from a post-operative abdominal wound. Based on morphological and biochemical criteria, strain MX 1040 ( = CCUG 54731^T) was tentatively identified as Bacteroidaceae but did not correspond to any recognized species of this family. Comparative 16S rRNA gene sequencing analysis demonstrated the organism to be related to species of the genus Dysgonomonas, although sequence divergence values of >5% with the other members of this genus demonstrated the organism to represent a novel species. Phylogenetic analysis revealed the novel organism to be most closely related to Dysgonomonas gadei. The major long-chain cellular fatty acids of the novel species consisted of iso-C_14:0, anteiso-C_15:0, C_16:0, and iso-C_16:0. Based on the phenotypic criteria and phylogenetic considerations, it is proposed that strain MX 1040 from a human clinical source represents a new species of the genus Dysgonomonas, as Dysgonomonas hofstadii sp. nov. The type strain of D. hofstadii is CCUG 54731^T ( = CCM 7606^T).     

Acidovorax, a new genus for Pseudomonas facilis, Pseudomonas delafieldii, E. Falsen (EF) group 13, EF group 16, and several clinical isolates, with the species Acidovorax facilis comb. nov., Acidovorax delafieldii comb. nov., and Acidovorax temperans sp. nov

Pseudomonas facilis and Pseudomonas delafieldii are inappropriately assigned to the genus Pseudomonas. They belong to the acidovorans rRNA complex in rRNA superfamily III (i.e., the beta subclass of the Proteobacteria). The taxonomic relationships of both of these species, two groups of clinical isolates (E. Falsen [EF] group 13 and EF group 16), and several unidentified or presently misnamed strains were examined by using DNA:rRNA hybridization, numerical analyses of biochemical and auxanographic features and of fatty acid patterns, polyacrylamide gel electrophoresis of cellular proteins, and DNA:DNA hybridization. These organisms form a separate group within the acidovorans rRNA complex, and we propose to transfer them to a new genus, Acidovorax. We describe the following three species in this genus: the type species, Acidovorax facilis (formerly Pseudomonas facilis), with type strain LMG 2193 (= CCUG 2113 = ATCC 11228); Acidovorax delafieldii (for the former Pseudomonas delafieldii and most of the EF group 13 strains), with type strain LMG 5943 (= CCUG 1779 = ATCC 17505); and Acidovorax temperans (for several former Pseudomonas and Alcaligenes strains and most of the EF group 16 strains), with type strain CCUG 11779 (= LMG 7169).     

Clostridium bolteae sp. nov., isolated from human sources

Seven obligately anaerobic, gram-positive, rod-shaped, spore-forming organisms isolated from human sources were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing showed that the strains were genetically highly related to each other (displaying >99% sequence similarity) and represent a previously unknown sub-line within the Clostridium coccoides rRNA group of organisms. Strains of the unidentified bacterium used carbohydrate as fermentable substrates, producing acetic acid and lactic acid as the major products of glucose metabolism. The closest described species to the novel bacterium corresponded to Clostridium clostridioforme, although a 16S rRNA sequence divergence of 3% demonstrated they represent different species. Genomic DNA-DNA pairing studies confirmed the separateness of the unknown species and Clostridium clostridioforme. Based on phenotypic and phylogenetic evidence, it is therefore proposed that the unknown bacterium, be classified as Clostridium bolteae sp. nov. The type strain of Clostridium bolteae is WAL 16351T (= ATCC(T) = BAA-613T, CCUG(T) = 46953T).     

Azospirillum himalayense sp. nov., a nifH bacterium isolated from Himalayan valley soil,India

Gram-negative, free-living bacterial strain ptl-3^T was isolated from Himalayan valley soil, India. Polyphasic taxonomy was performed including morphological characterization, fatty acid analysis, biochemical tests, 16S rRNA and nifH gene sequence analyses. 16S rRNA gene sequence analysis showed that the strain ptl-3^T belonged to the genus Azospirillum and was closely related to A. brasilense (98.7 % similarity) and A. rugosum (97 % similarity). 16S rRNA gene sequence similarity (96–95 %) was shown with other members of the genus Azospirillum. Major fatty acid 18:1ω7c was also similar to the genus Azospirillum. DNA–DNA relatedness value between strain ptl-3^T and A. brasilense was found to be 47 %. Various biochemical tests showed that the strain ptl-3^T differed from its closely related species A. brasilense. On the basis of phenotypic, chemotaxonomic and molecular genetics evidence, a bacterium with the type strain ptl-3^T is proposed as a novel species of the genus Azospirillum. The name of bacterial strain ptl-3^T has been proposed as Azospirillum himalayense sp. nov. The type strain of ptl-3^T (CCUG 58760^T, KCTC 23189^T) has been submitted to two culture collection centres. The accession numbers for 16S rRNA and nifH gene are GQ 284588 and GQ 249665. respectively.     

Nocardia bhagyanesis sp. nov., a novel actinomycete isolated from the rhizosphere of Callistemon citrinus (Curtis), India

A novel actinomycete strain, designated VRC07^T, was isolated from a Callistemon citrinus rhizosphere sample collected from Hyderabad, India. Its taxonomic status was determined by using polyphasic approach. It is a Gram-positive, aerobic, non-motile, weakly acid-fast strain. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain VRC07^T is a member of the genus Nocardia. The highest levels of 16S rRNA gene sequence similarity was found between the strains Nocardia niwae W9241^T (99.6 %), Nocardia amikacinitolerans W9988^T (99.3 %) and Nocardia arthritidis IFM 10035^T (98.9 %); similarity to other type strains of the genus Nocardia was below 98.7 %. The organism had chemical and morphological features consistent with its classification in the genus Nocardia such as meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall peptidoglycan. Arabinose and galactose as the diagnostic sugars. Diagnostic polar lipids were phosphatidylinositol, diphosphatidylglycerol, and phosphatidylglycerol. The predominant menaquinone was MK-8(H_{4, ω-cycl}). The major fatty acids were C_16:0, C_18:0, C_{18:1 w9c}, C_{18:0 10-methyl TBSA} and sum in feature 3 (16:1 w7c/16:1 w6c). The G+C content of the genomic DNA was 68.5 mol%. The DNA–DNA relatedness data, together with phenotypic differences clearly distinguished the isolate from its closest relatives. On the basis of these phenotypic and genotypic data, the isolate represents a novel species, for which the name Nocardia bhagyanesis sp. nov., is proposed. The type strain is VRC07^T (=KCTC 29209^T = MTCC 11725^T = ATCC BAA-2548).     

Description of the two novel species of the genus Helicobacter: Helicobacter anatolicus sp. nov., and Helicobacter kayseriensis sp. nov., isolated from feces of urban wild birds

A total of 26 Gram-negative, motile, gently curved, and rod-shaped isolates were recovered, during a study to determine the faeco-prevalence of Helicobacter spp. in urban wild birds. Pairwise comparisons of the 16S rRNA gene sequences indicated that these isolates belonged to the genus Helicobacter and phylogenetic analysis based on the 16S rRNA gene sequences showed that the isolates were separated into two divergent groups. The first group consisted of 20 urease-positive isolates sharing the highest 16S rRNA gene sequence identity levels of 98.5–98.6% to H. mustelae ATCC 43772^T, while the second group contained six urease-negative isolates with the sequence identity level of 98.5% to the type strain of H. pametensis ATCC 51478^T. Five isolates were chosen and subjected to comparative whole-genome analysis. The phylogenetic analysis of the 16S rRNA, gyrA and atpA gene sequences showed that Helicobacter isolates formed two separate phylogenetic clades, differentiating the isolates from the other Helicobacter species. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses between strains faydin-H8^T, faydin-H23^T and their close neighbors H. anseris MIT 04-9362^T and H. pametensis ATCC 51478^T, respectively, confirmed that both strains represent novel species in the genus Helicobacter. The DNA G+C contents of the strains faydin-H8^T and faydin-H23^T are 32.0% and 37.6%, respectively. The results obtained for the characterization of the wild bird isolates indicate that they represent two novel species, for which the names Helicobacter anatolicus sp. nov., and Helicobacter kayseriensis sp. nov., are proposed, with faydin-H8^T(=LMG 32237^T = DSM 112312^T) and faydin-H23^T(=LMG 32236^T = CECT 30508^T) as respective type strains.     

Mycoplasma tauri sp. nov. isolated from the bovine genital tract

Since 2006, a Mycoplasma species unidentifiable to the species level has been regularly isolated from the semen and prepuce of apparently healthy bulls, and occasionally from cattle displaying inflammatory disease of the genital tract. Seven of these Mycoplasma isolates were subjected to a comprehensive taxonomic study. The strains investigated grew well in modified Hayflick’s medium and colonies on agar exhibited typical fried egg morphology and produced ‘film and spots’. Transmission electron microscopy revealed a cell morphology characteristic of mycoplasmas with spherically shaped cells bounded by a bi-layered cell membrane. The strains studied neither produced acid from sugar carbon sources nor did hydrolyse arginine or urea, and genome annotation indicated that organic acids (pyruvate, lactate) are used as energy sources. Phylogenetic analyses of 16S rRNA gene sequences, the 16S-23S intergenic spacer region, and partial rpoB gene and protein sequences placed the strains within the Mycoplasma (M.) bovis cluster of the Hominis group with M. primatum, M. agalactiae, and M. bovis being their closest relatives. Genomic information including whole-genome similarity metrics (ANIb, ANIm, TETRA, dDDH, AAI) and phylogenomics, proteomic features revealed by matrix-assisted laser desorption ionization time of flight (MALDI-ToF) mass spectrometry as well as serological reactions and polar lipid profiling strongly indicated that the strains examined were representatives of a hitherto unclassified species of genus Mycoplasma, for which the name Mycoplasma tauri sp. nov. with type strain Zaradi2^T (=ATCC BAA-1891^T = DSM 22451^T) is proposed.     

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

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.