Reclassification of Bacteroides putredinis (Weinberg et al., 1937) in a new genus Alistipes gen. nov., as Alistipes putredinis comb. nov., and description of Alistipes finegoldii sp. nov., from human sources

During studies on the bacteriology of appendicitis in children, we often isolated from inflamed and non-inflamed tissue samples, an unusual bile-resistant pigment-producing strictly anaerobic gram-negative rod. Phenotypically this organism resembles members of Bacteroides fragilis group of species, as it is resistant to bile and exhibits a special-potency-disk pattern (resistance to vancomycin, kanamycin and colistin) typical for the B. fragilis group. However, the production of brown pigment on media containing haemolysed blood and a cellular fatty acid composition dominated by iso-C15:0, suggests that the organism most closely resembles species of the genus Porphyromonas. However, the unidentified organism differs from porphyromonads by being bile-resistant and by not producing butyrate as a metabolic end-product. Comparative 16S ribosomal RNA gene sequencing studies show the unidentified organism represents a distinct sub-line, associated with but distinct from, the miss-classified species Bacteroides putredinis. The clustering of the unidentified bacterium with Bacteroides putredinis was statistically significant, but they displayed > 4% sequence divergence with each other. Chromosomal DNA-DNA pairing studies further confirmed the separateness of the unidentified bacterium and Bacteroides putredinis. Based on phenotypic and phylogenetic considerations, it is proposed that Bacteroides putredinis and the unidentified bacterium from human sources be classified in a new genus Alistipes, as Alistipes putredinis comb. nov. and Alistipes finegoldii sp. nov., respectively. The type strain of Alistipes finegoldii is CCUG 46020(T) (= AHN243(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).     

Subdoligranulum variabile gen. nov., sp. nov. from human feces

During studies on the microflora of human feces we have isolated a strictly anaerobic, non-spore-forming, Gram-negative staining organism which exhibits a somewhat variable coccus-shaped morphology. Comparative 16S ribosomal RNA gene sequencing studies show the unidentified organism is phylogenetically a member of the Clostridium leptum supra-generic rRNA cluster and displays a close affinity to some rDNA clones derived from human and pig feces. The nearest named relatives of the unidentified isolate corresponded to Faecalibacterium prausnitzii (formerly Fusobacterium prausnitzii) displaying a 16S rRNA sequence divergence of approximately 9%, with Anaerofilum agile and A. pentosovorans the next closest relatives of the unidentified bacterium (sequence divergence approximately 10%). Based on phenotypic and phylogenetic considerations, it is proposed that the unusual coccoid-shaped organism be classified as a new genus and species, Subdoligranulum variabile. The type strain of S. variabile is BI 114(T) (=CCUG 47106(T)=DSM 15176(T)).     

Clostridium asparagiforme sp. nov., isolated from a human faecal sample

An obligatory anaerobic, Gram-positive, rod-shaped organism was isolated from faeces of a healthy human donor. It was characterized using biochemical, phenotypic and molecular taxonomic methods. The organism produced acetate, lactate, and ethanol as the major products of glucose fermentation. The G + C content was 53 mol%. Based on comparative 16S rRNA gene sequencing, the unidentified bacterium is a member of the Clostridium subphylum of the Gram-positive bacteria, and most closely related to species of the Clostridium coccoides cluster (rRNA cluster XIVa) [M.D. Collins et al., The phylogeny of the genus Clostridium: proposal of five new genera and eleven new species combinations, Int. J. Syst. Bacteriol. 44 (1994) 812-826]. Clostridium bolteae and Clostridium clostridioforme were identified as the most closely related described species. A 16S rRNA sequence divergence value of > 3% suggested that the isolate represents a new species. This was also supported by the gyrase-encoding gyrB gene sequences. Based on these findings, we propose the novel bacterium from human faeces to be classified as a new species, Clostridium asparagiforme. The type strain of C. asparagiforme is N6 (DSM 15981 and CCUG 48471).     

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).     

Streptococcus devriesei sp. nov., from equine teeth

Phenotypic and phylogenetic studies were performed on four unidentified Gram-positive staining, catalase-negative, alpha-hemolytic Streptococcus-like organisms recovered from the teeth of horses. SDS PAGE analysis of whole-cell proteins and comparative 16S rRNA gene sequencing demonstrated the four strains were highly related to each other but that they did not correspond to any recognised species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms form a hitherto unknown sub-line within the Streptococcus genus, displaying a close affinity with Streptococcus mutans, Streptococcus ferus and related organisms. Sequence divergence values of > 5% with these and other reference streptococcal species however demonstrated the organisms from equine sources represent a novel species. Based on the phenotypic distinctiveness of the new bacterium and molecular chemical and molecular genetic evidence, it is proposed that the unknown species be classified as Streptococcus devriesei sp. nov. The type strain of Streptococcus devriesei is CCUG 47155T (= CIP 107809T).     

Leucobacter luti sp. nov., and Leucobacter alluvii sp. nov., two new species of the genus Leucobacter isolated under chromium stress

Two strains designated RF6(T) and RB10(T) were isolated, from activated sludge and from river sediments, respectively, both systems receiving chromium contaminated water. Phylogenetic analysis showed that strain RF6(T)and strain RB10(T) represented two new species of the genus Leucobacter. Strain RB10(T) can be distinguished from RF6(T) by its ability to grow at 37 degrees C, by showing a different optimum pH, by cell wall amino acids different relative amount and by having the fatty acid strait C16:0 as the third most abundant fatty acid. On the basis of the distinct peptidoglycan composition, 16S ribosomal DNA sequence analysis, DNA-DNA reassociation values, and phenotypic characteristics we are of the opinion that strain RF6(T) represents a new species of the genus Leucobacter for which we propose the name Leucobacter luti (CIP 108818(T)=LMG 23118) and that strain RB10(T) represents an additional new species of the same genus for which we propose the name Leucobacter alluvii (CIP 108819(T)=LMG 23117).     

Clostridium hathewayi sp. nov., from human faeces

A strictly anoxic, Gram-positive, sporeforming, rod-shaped bacterium was isolated from a chemostat inoculated with human faeces. The bacterium used carbohydrate as fermentable substrates, producing acetate, ethanol, carbon dioxide and hydrogen as the major products of glucose metabolism, and possessed a G + C content of 50.7 to 50.9 mol%. Comparative 16S rRNA gene sequencing showed that the unidentified bacterium represents a previously unrecognised sub-line within the Clostridium coccoides rRNA group of organisms. The nearest relatives of the unknown bacterium corresponded to Clostridium algidixylanolyticum, C. aerotolerans, C. celerecrescens, C. indolis, C. sphenoides, C. methoxybenzovorans and C. xylanolyticum but 16S rRNA sequence divergence values of >4% demonstrated that it represents a novel species. Based on the presented findings a new species, Clostridium hathewayi, is described. The type strain of Clostridium hathewayi is DSM = 13479T (= CCUG 43506 T).     

Phenylobacterium falsum sp. nov., an Alphaproteobacterium isolated from a nonsaline alkaline groundwater, and emended description of the genus Phenylobacterium

A Gram-negative bacterium designated AC-49T was isolated from an alkaline groundwater with a pH 11.4. This organism formed rod-shaped cells, was strictly aerobic, catalase and oxidase positive, with an optimum growth temperature of 35 degrees C and an optimum pH value of 8.0. Strain AC-49T assimilated primarily amino acids and some Krebs cycle metabolites, did not use sugars for growth. The organism did not grow on L-phenylalanine or antipyrin. The G+ C content of DNA was 66.9 mol%. The phylogenetic analyses based on the 16S rRNA sequencing showed that the closest relatives of strain AC-49T were Phenylobacterium lituiforme and Phenylobacterium immobile, indicating that the organism is a member of the order Caulobacterales of the Alphaproteobacteria. Based on the phylogenetic analyses and distinct phenotypic characteristics, we are of the opinion that strain AC-49T, represents a novel species of the genus Phenylobacterium for which we propose the name Phenylobacterium falsum sp. nov.     

Assignment of<Emphasis Type="Italic"> Pseudomonas</Emphasis> sp. strain E-3 to<Emphasis Type="Italic"> Pseudomonas psychrophila</Emphasis> sp. nov., a new facultatively psychrophilic bacterium

A facultatively psychrophilic bacterium, previously described as Pseudomonas sp. strain E-3, has been reassigned by phenotypic characterization, chemotaxonomic analysis, DNA-DNA hybridization, and 16S rRNA gene phylogenetic analysis. The organism was a gram-negative, aerobic. straight rod with polar flagella. It was catalase positive and oxidase positive, able to grow at -1 degree C but not at 40 degree C, and produced acid from D-glucose under aerobic conditions. The major isoprenoid quinone was ubiquinone-9, and the DNA G + C content was 57.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the bacterium is a member of the genus Pseudomonas and was closest to Pseudomonas fragi. Determination of the DNA-DNA relatedness between strain E-3 and P. fragi revealed too low a level of homology (47.9%-51.3%) to identify them as the same species. On the basis of phenotypic characteristics, phylogenetic analysis, and DNA-DNA relatedness data, it is concluded that strain E-3 represents an individual species. Accordingly, the name Pseudomonas psychrophila is proposed. The type strain is E-3T (= JCM 10889).     

Allobaculum stercoricanis gen. nov., sp. nov., isolated from canine feces

Morphological, biochemical, and molecular genetic studies were performed on an unknown anaerobic, catalase-negative, non-spore-forming, rod-shaped bacterium isolated from dog feces. The unknown bacterium was tentatively identified as a Eubacterium species, based on cellular morphological and biochemical tests. 16S rRNA gene sequencing studies, however, revealed that it was phylogenetically distant from Eubacterium limosum, the type species of the genus Eubacterium. Phylogenetically, the unknown species forms a hitherto unknown sub-line proximal to the base of a cluster of organisms (designated rRNA cluster XVI), which includes Clostridium innocuum, Streptococcus pleomorphus, and some Eubacterium species. Based on both phenotypic and phylogenetic criteria, it is proposed that the unknown bacterium be classified as a new genus and species, Allobaculum stercoricanis. Using a specific rRNA-targeted probe designed to identify Allobaculum stercoricanis, in situ hybridisation showed this novel species represents a significant organism in canine feces comprising between 0.1% and 3.7% of total cells stained with DAPI (21 dog fecal samples). The type strain of Allobaculum stercoricanis is DSM 13633(T)=CCUG 45212(T).     

<Emphasis Type="Italic">Arthrobacter soli</Emphasis> sp. nov., a novel bacterium isolated from wastewater reservoir sediment

A novel Gram-positive bacterium, designated SYB2T, was isolated from wastewater reservoir sediment, and a polyphasic taxonomic study was conducted based on its morphological, physiological, and biochemical features, as well as the analysis of its 16S rRNA gene sequence. During the phylogenetic analysis of the strain SYB2T, results of a 16S rRNA gene sequence analysis placed this bacterium in the genus Arthrobacter within the family Micrococcaceae. SYB2T and Arthrobacter protophormiae ATCC 19271T, the most closely related species, both exhibited a 16S rRNA gene sequence similarity of 98.99%. The genomic DNA G+C content of the novel strain was found to be 62.0 mol%. The predominant fatty acid composition was anteiso-C15:0, anteiso-C17:0, iso-C16:0, and iso-C15:0. Analysis of 16S rRNA gene sequences and DNA-DNA relatedness, as well as physiological and biochemical tests, showed genotypic and phenotypic differences between strain SYB2T and other Arthrobacter species. The type strain of the novel species was identified as SYB2T (= KCTC 19291T= DSM 19449T).     

Atopostipes suicloacale gen. nov., sp. nov., isolated from an underground swine manure storage pit

Phenotypic and molecular genetic studies were performed on an unknown facultative anaerobic, catalase-negative, non-spore-forming, rod-shaped bacterium isolated from a pig manure storage pit. The unknown bacterium was nutritionally fastidious with growth enhanced by the addition of rumen fluid and was phenotypically initially identified as an Eubacterium species. Comparative 16S rRNA gene sequencing studies, however, revealed that the unknown bacterium was phylogenetically distant from Eubacterium limosum (the type species of the genus Eubacterium) and related organisms. Phylogenetically, the unknown species displayed a close association with an uncultured organism from human subgingival plaque and formed an unknown sub-line within a cluster of organisms which includes Alloioccoccus otitis, Alkalibacterium olivoapovliticus, Allofustis seminis, Dolosigranulum pigrum, and related organisms, within the low mol% G+C Gram-positive bacteria. Sequence divergence values of >8% with all known taxonomically recognised taxa, however, clearly indicates the novel bacterium represents a hitherto unknown genus. Based on both phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium from pig manure be classified in a new genus and species, as Atopostipes suicloacale gen. nov., sp. nov. The type strain of Atopostipes suicloacale is PPC79(T)=NRRL 23919(T)=DSM 15692(T).     

Alkanindiges hongkongensis sp. nov. A novel Alkanindiges species isolated from a patient with parotid abscess

A bacterium was isolated from the abscess pus of a 72-year-old patient with Warthin's tumor and parotid abscess. The cells were aerobic, non-motile, Gram-negative but difficult to be destained, non-sporulating, coccobacillus. The bacterium grew poorly on sheep blood agar and MacConkey agar as non-hemolytic colonies of 0.5 mm in diameter after 24h of incubation at 37 degrees C in ambient air. Growth was enhanced by Tween 80. It produces catalase but not cytochrome oxidase. Sequencing of the cloned 16S rRNA PCR products of the bacterium revealed three different 16S rRNA gene sequences, with 12 - 31 bp differences among them. Phylogenetic analysis showed that the bacterium is closely related to Alkanindiges illinoisensis, with 5.0 - 5.9% differences between the 16S rRNA gene sequence of the bacterium and that of A. illinoisensis. Tryptophan auxotrophic strain of Acinetobacter trpE27 transformed with DNA extracted from the bacterium was unable to grow on tryptophan deficient medium, indicating that the bacterium was not a strain of Acinetobacter. The G+C content of the bacterium (mean +/-SD) was 46.9+4.3%. A new species, Alkanindiges hongkongensis sp. nov., is proposed, for which HKU9T is the type strain. Isolates with "small colonies" that are apparently Acinetobacter-like species should be carefully identified. Growth enhancement with aliphatic hydrocarbons should be looked for and 16S rRNA gene sequencing performed in order to find more potential cases of Alkanindiges infections, as well as to define the epidemiology, clinical spectrum, and outcome of infections associated with this genus.     

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.7% similarity) and Clostridium ramosum (96.6%). In contrast to these species, the isolate was devoid of alpha-galactosidase and -glucosidase and did not grow on maltose, melibiose, raffinose, rhamnose and trehalose. The hypothesis that strain SDG-Mt85-3Db represents a new bacterial species of the Clostridium cluster XVIII was confirmed by DNA-DNA hybridisation experiments. The G+C content of DNA of strain SDG-Mt85-3Db (30.7+/-0.8 mol%) was comparable with that of Clostridium butyricum, the type species of the genus Clostridium. The name Clostridium saccharogumia is proposed for strain SDG-Mt85-3Db (=DSM 17460T=CCUG 51486T). The second isolate, strain ED-Mt61/PYG-s6, was a mesophilic strictly anaerobic Gram-positive regular rod. Based on 16S rRNA gene sequence analysis, its nearest relatives were Clostridium amygdalinum (93.3%), Clostridium saccharolyticum (93.1%) and Ruminococcus productus (93.0%). The isolate differed from these species in its ability to dehydrogenate enterodiol. It also possessed alpha-arabinosidase and -galactosidase and had a higher G+C content of DNA (48.0 mol%). According to these findings, it is proposed to create a novel genus, Lactonifactor, and a novel species, Lactonifactor longoviformis, to accommodate strain ED-Mt61/PYG-s6. The type strain is DSM 17459T (=CCUG 51487T).     

Phenylobacterium zucineum sp. nov., a facultative intracellular bacterium isolated from a human erythroleukemia cell line K562

A bacterial strain HLK1(T) was isolated from the human erythroleukemia cell line K562. This bacterium is a Gram-negative rod, motile with a polar flagellum. It is strictly aerobic, nonfermentative, and oxidase and catalase positive. Its optimal growth occurs at 37 degrees C at pH between 6.5 and 7.5. Phylogenetically, although it shares 98% similarity with the 16S rRNA of Phenylobacterium lituiforme, the DNA-DNA hybridization value between the two species is only 43%. HLK1(T) has a DNA G+C content of 71.2+/-0.2 mol%. It is a facultative intracellular organism and may have pathogenic relevance with humans and mammals. On the basis of the phylogenetic and phenotypic characterization, strain HLK1(T) is proposed to be classified in the genus Phenylobacterium, as P. zucineum sp. nov. The type strain is HLK1(T) (=CGMCC 1.3786(T), DSM=18354).     

Pseudoxanthomonas kaohsiungensis, sp. nov., a novel bacterium isolated from oil-polluted site produces extracellular surface activity

During screening for biosurfactant-producing bacteria, a strain designated J36T was isolated from oil-polluted site near Kaohsiung city located in southern Taiwan. Cells of this organism were gram-negative rods motile by means of a single polar flagellum. Strain J36T grew well in complex media under optimum conditions of 35 degrees C and pH 7. The extracellular products of the strain expressed emulsification activity. During cultivation on olive oil as the sole carbon and energy source, the culture supernatant of strain J36T reduced surface tension of the medium from 68 to 32.6 dyne/cm. The 16S rRNA gene sequence analysis indicates that strain J36T is a member of Xanthomonas group within the gamma-Proteobacteria. The organism belongs to the genus Pseudoxanthomonas and represents a novel species within this genus according to phylogenetic analysis of 16S rDNA sequences, DNA-DNA similarity data, whole-cell protein analysis, physiological and biochemical characteristics, as well as fatty acid compositions. The predominant cellular fatty acids of strain J36T were 15:0 iso (about 26%), 17:1 iso omega9c (about 25%), and 15:0 anteiso (about 10%). Its DNA base ratio was 60.1 mol% G+C. We propose to classify strain J36T (= BCRC 17375T = LMG 22530T) as Pseudoxanthomonas kaohsiungensis sp. nov.     

Desulfovibrio longus sp. nov., a sulfate-reducing bacterium isolated from an oil-producing well.

A novel type of sulfate-reducing bacteria with unusual morphology was isolated from an oil-producing well in the Paris Basin. The cells of this bacterium, strain SEBR 2582T (T = type strain), are long, thin, flexible rods, contain desulfoviridin, and are physiologically similar to members of the genus Desulfovibrio. On the basis of 16S rRNA sequence data, this strain should be included in the genus Desulfovibrio. However, strain SEBR 2582T differs from other members of this genus morphologically, physiologically, and phylogenetically. Thus, a new species, Desulfovibrio longus sp. nov., is proposed for this organism.     

Tepidimonas aquatica sp. nov., a new slightly thermophilic beta-proteobacterium isolated from a hot water tank

A bacterial isolate, with an optimum growth temperature of about 50 degrees C, was recovered from a domestic hot water tank in Coimbra. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain CLN-1T is a member of the beta-Proteobacteria and represents a new species of the genus Tepidimonas. The major fatty acids of strain CLN-1T are 16:0, 17:0 cyclo and 16:1 omega7c. Ubiquinone 8 is the major respiratory quinone, the major polar lipids are phosphatidylethanolamine, and phosphatidylglycerol. The new isolate is aerobic and facultatively chemolithoheterotrophic. Thiosulfate and tetrathionate are oxidized to sulfate in the presence of a metabolizable carbon source. Strain CLN-1T grows on amino acids and organic acids, but this organism does not assimilate carbohydrates. Glycerol is the only polyol assimilated. Resinic acids, namely abietic acid, dehydroabietic acid and isopimaric acid are not degraded. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we propose that strain CLN-1T represents a new species for which we offer the name Tepidimonas aquatica.     

Rubritepida flocculans gen. nov., sp. nov., a new slightly thermophilic member of the alpha-1 subclass of the Proteobacteria

A bacterial isolate, with an optimum growth temperature of about 50 degrees C, was recovered from the hot spring at Egerszalók in Hungary. Phylogenetic analyses using the 16S rRNA gene sequence of strain H-8T indicated that the new organism represented a new genus and species of alpha-1 subclass of the Proteobacteria. The major fatty acids of strain H-8T are 16:0, 18:1 omega7c; the rare fatty acid 19:0 20H cyclo 11,12 is also present. Ubiquinone 9 is the major respiratory quinone, the polar lipids are phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol in addition to two unidentified aminolipids. The new isolate forms red-colored colonies, flocculates in liquid media, is heterotrophic and strictly aerobic. Thiosulfate is oxidized to sulfate, but an increase in biomass could not be measured because of the flocculating behavior. Bacteriochloropyll a was detected by direct spectrophotometric analysis when the organism was grown at 30 degrees C, but could not be detected after growth at 50 degrees C. pufL and pufM genes were present. Heterotrophic growth of strain H-8T occurs on a few carbohydrates, amino acids and organic acids. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we propose that strain H-8T represents a new genus and a new species most closely related to Roseococcus thiosulfatophilus for which we propose the name Rubritepida flocculans.