Christensenella strain resources, genomic/metabolomic profiling, and association with host at species level.

The gut commensal bacteria Christensenellaceae species are negatively associated with many metabolic diseases, and have been seen as promising next-generation probiotics. However, the cultured Christensenellaceae strain resources were limited, and their beneficial mechanisms for improving metabolic diseases have yet to be explored. In this study, we developed a method that enabled the enrichment and cultivation of Christensenellaceae strains from fecal samples. Using this method, a collection of Christensenellaceae Gut Microbial Biobank (ChrisGMB) was established, composed of 87 strains and genomes that represent 14 species of 8 genera. Seven species were first described and the cultured Christensenellaceae resources have been significantly expanded at species and strain levels. Christensenella strains exerted different abilities in utilization of various complex polysaccharides and other carbon sources, exhibited host-adaptation capabilities such as acid tolerance and bile tolerance, produced a wide range of volatile probiotic metabolites and secondary bile acids. Cohort analyses demonstrated that Christensenellaceae and Christensenella were prevalent in various cohorts and the abundances were significantly reduced in T2D and OB cohorts. At species level, Christensenellaceae showed different changes among healthy and disease cohorts. C. faecalis, F. tenuis, L. tenuis, and Guo. tenuis significantly reduced in all the metabolic disease cohorts. The relative abundances of C. minuta, C. hongkongensis and C. massiliensis showed no significant change in NAFLD and ACVD. and C. tenuis and C. acetigenes showed no significant change in ACVD, and Q. tenuis and Geh. tenuis showed no significant change in NAFLD, when compared with the HC cohort. So far as we know, this is the largest collection of cultured resource and first exploration of Christensenellaceae prevalences and abundances at species level.

Reclassification of Aestuariicella albida as Pseudomaricurvus albidus comb. nov. and Aestuariicella hydrocarbonica as Pseudomaricurvus hydrocarbonicus comb. nov. Based on Comparative Genomics and Molecular Synapomorphies.

The genus Aestuariicella has been recently reclassified as a member of the family Cellvibrionaceae. However, the taxonomic position of the genus as a distinct member of the family has not been clarified. In the present study, we performed multilayered analyses anchored on genome sequences to clarify the relationship between the genera Aestuariicella and Pseudomaricurvus within the family Cellvibrionaceae. Phylogenetic analyses based on 16S rRNA gene, RNA polymerase beta subunit (RpoB) protein, and core gene sequences showed a well-supported tight cluster formed by the members of the two genera. Moreover, the analysis of the average amino acid identity (AAI) revealed that the members of the two genera shared 68.16-79.48% AAI, values which were within the range of observed AAI (≥ 67.23%) among the members of the same genus within the family Cellvibrionaceae. Members of the two genera also shared several common characteristics. Furthermore, molecular synapomorphies in a form of conserved signature indels were identified in six protein sequences that were exclusively shared by the members of the two genera. Based on the phylogenetic and molecular evidence presented here, we propose the reclassification of the species Aestuariicella albida and Aestuariicella hydrocarbonica as Pseudomaricurvus albidus comb. nov. and Pseudomaricurvus hydrocarbonicus comb. nov., respectively.

Hungatella hathewayi bacteremia due to acute appendicitis: A case report and a narrative review.

Hungatella species, including Hungatella hathewayi and Hungatella effluvii, previously identified as part of the Clostridium genus, are anaerobic bacteria primarily residing in the gut microbiome, with infrequent implications in human infections. This article presents the case of an 87-year-old Asian male admitted for a hyperosmolar hyperglycemic state with septic shock secondary to Hungatella hathewayi bacteremia originating from acute appendicitis. Remarkably, the bacterium was detected in the blood 48 hours before the emergence of clinical and radiographic evidence of acute appendicitis. Additionally, we conducted a literature review to identify all documented human infections caused by Hungatella species. Timely microbial identification in such cases is essential for implementing targeted antibiotic therapy and optimizing clinical outcomes.

Blautia parvula sp. nov., isolated from Japanese faecal samples.

Two Gram-positive, anaerobic, non-spore-forming and coccoid or oval-shaped bacterial strains, namely, DN0138T and DN0266, were isolated from faecal samples of healthy Japanese people. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DN0138T clustered with a species of the genus Blautia and was closely related to Blautia producta JCM 1471T, Blautia coccoides JCM 1395T, Blautia hominis KB1T and 'Blautia marasmi' Marseille-P2377, with sequence similarities of 98.6, 98.5, 98.8 and 98.2 %, respectively. The average nucleotide identity values were 85.3 % for B. producta JCM 1471T, 85.0 % for B. coccoides NCTC 11035T, 84.3 % for B. hominis KB1T and 84.3 % for 'B. marasmi' Marseille-P2377. The major end products of glucose metabolism were acetic acid, lactic acid and succinic acid. The genome length of strain DN0138T was 6 247 046 bp with 46.7 mol% G+C content of genome sequence. Based on their phenotypic, cellular fatty acid and phylogenetic characteristics, the three isolates represent a novel species within the genus Blautia, for which the name Blautia parvula sp. nov. is proposed. The type strain is DN0138T (=NBRC 113351T=BCRC 81349T).

Profiling Blautia at high taxonomic resolution reveals correlations with cognitive dysfunction in Chinese children with Down syndrome.

Introduction: Down syndrome (DS), the presence of a supernumerary chromosome 21, is associated with cognitive dysfunction caused by early neurodegenerative processes. Alterations in the gut microbiota were observed in Chinese children with DS, and the genus Blautia was associated with cognitive function in these children. Therefore, it is crucial to understand the detailed composition of this group at the species level and to explore the effect of specific species on cognitive function. Methods: In this study, Blautia-specific amplicon sequencing was conducted to identify the specific Blautia species in 15 children with DS and 15 matched healthy children. Results: The taxonomic analyses suggested that the Blautia taxa were clustered by disease status. The diversity of Blautia at the species level differed between DS patients and healthy controls, with the abundances of Blautia massiliensis and Blautia argi decreasing in DS children, while Blautia faecis was increased. Acetic acid, one of the metabolites of Blautia, was significantly reduced in the DS group. Of particular interest, Kyoto Encyclopaedia of Genes and Genomes analysis revealed decreased modules related to starch and sucrose metabolism and glycolysis. In addition, B. argi was positively related to DS cognitive scores, and B. faecis was negatively related to cognitive function, implying its role on the DS cognitive impairments. Discussion: Our study has important implications for understanding the important effects of specific species of Blautia on cognitive function and thus possibly provides a new strategy for future studies of cognitive improvement in individuals with DS.

Description of a Newly Isolated Blautia faecis Strain and Its Benefit in Mouse Models of Post-Influenza Secondary Enteric and Pulmonary Infections.

The expanding knowledge on the systemic influence of the human microbiome suggests that fecal samples are underexploited sources of new beneficial strains for extra-intestinal health. We have recently shown that acetate, a main circulating microbiota-derived molecule, reduces the deleterious effects of pulmonary Streptococcus pneumoniae and enteric Salmonella enterica serovar Typhimurium bacterial post-influenza superinfections. Considering the beneficial and broad effects of acetate, we intended to isolate a commensal strain, producing acetate and potentially exploitable in the context of respiratory infections. We designed successive steps to select intestinal commensals that are extremely oxygen-sensitive, cultivable after a freezing process, without a proinflammatory effect on IL-8 induction, and producing acetate. We have identified the Blautia faecis DSM33383 strain, which decreased the TNFα-induced production of IL-8 by the intestinal epithelial cell line HT-29. The beneficial effect of this bacterial strain was further studied in two preclinical models of post-influenza Streptococcus pneumoniae (S.p) and Salmonella enterica serovar Typhimurium (S.t) superinfection. The intragastrical administration of Blautia faecis DSM33383 led to protection in influenza-infected mice suffering from an S.p. and, to a lesser extent, from an S.t secondary infection. Altogether, this study showed that Blautia faecis DSM33383 could be a promising candidate for preventive management of respiratory infectious diseases.

Faecalicatena absiana sp. nov., an obligately anaerobic bacterium from a pig farm faeces dump.

An obligately anaerobic, Gram-stain-positive, spore-forming, short-rod-shaped bacterium, designated strain YH-C36aT, was isolated from a pig farm faeces dump. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Faecalicatena and is most closely related to Faecalicatena contorta KCTC 5831T, Faecalicatena fissicatena KCTC 15010T and Faecalicatena orotica KCTC 15331T, with 96.3, 96.2, and 96.0 % sequence similarity, respectively. The average nucleotide identity values for strain YH-C36aT and the closest related strains were lower than 72 %. The G+C content of the isolate was 43.0 mol%. The cell-wall peptidoglycan was A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C16 : 0, C18 : 1 cis 9, C16 : 0 DMA, C18 : 0 DMA and C18:0. The major end products of glucose fermentation were lactate, formate and acetate. Based on its phenotypic, phylogenetic and chemotaxonomic properties, a novel species, named Faecalicatena absiana sp. nov., is proposed for strain YH-C36aT (=KCTC 25106T=NBRC 114768T).

Variimorphobacter saccharofermentans gen. nov., sp. nov., a new member of the family Lachnospiraceae, isolated from a maize-fed biogas fermenter.

Strain MD1T is an anaerobic, Gram-stain-negative bacterium isolated from a lab-scale biogas fermenter fed with maize silage. It has a rod-shaped morphology with peritrichously arranged appendages and forms long chains of cells and coccoid structures. The colonies of MD1T were white, circular, slightly convex and had a smooth rim. The isolate is mesophilic, displaying growth between 25 and 45 °C with an optimum at 40 °C. It grew at pH values of pH 6.7-8.2 (optimum, pH 7.1) and tolerated the addition of up to 1.5% (w/v) NaCl to the medium. The main cellular fatty acids of MD1T are C14:0 DMA and C16:0. Strain MD1T fermented xylose, arabinose, glucose, galactose, cellobiose, maltose, maltodextrin10, lactose starch, and xylan, producing mainly 2-propanol and acetic acid. The genome of the organism has a total length of 4163427 bp with a G+C content of 38.5 mol%. The two closest relatives to MD1T are Mobilitalea sibirica P3M-3T and Anaerotaenia torta FH052T with 96.44 or 95.8 % 16S rRNA gene sequence similarity and POCP values of 46.58 and 50.58%, respectively. As MD1T showed saccharolytic and xylanolytic properties, it may play an important role in the biogas fermentation process. Closely related variants of MD1T were also abundant in microbial communities involved in methanogenic fermentation. Based on morphological, phylogenetic and genomic data, the isolated strain can be considered as representing a novel genus in the family Lachnospiraceae, for which the name Variimorphobacter saccharofermentans gen. nov., sp. nov. (type strain MD1T=DSM 110715T=JCM 39125T) is proposed.

Fusibacter ferrireducens sp. nov., an anaerobic, Fe(â ¢)- and sulphur-reducing bacterium isolated from mangrove sediment.

An anaerobic, alkaliphilic, halotolerant, Gram-stain-positive and rod-shaped bacterium, designated Q10-2T, was isolated from mangrove sediment sampled at the Jiulong river estuary, PR China. The cells of strain Q10-2T were motile and 0.5×2-4 µm in size. Strain Q10-2T grew at 8-45 °C (optimum, 32 °C), at pH 7.0-10.5 (optimum, pH 8.5) and in the presence of 0-6 % (w/v) NaCl (optimum, 3 %). It could use complex organic compounds and carbohydrates including d-fructose, d-galactose, d-glucose, d-mannitol, d-xylose, trehalose, lactose, maltose, sucrose and starch as carbon sources and electron donors. It could reduce sulphate, thiosulphate and elemental sulphur to sulphide, but not sulphite. Fe (Ⅲ) citrate, ferrihydrite, haematite and goethite in the presence of glucose as the electron donor were also reduced. Acetate, butyrate, ethanol, CO2 and H2 were end products of glucose fermentation. The predominant cellular fatty acids were composed of C14 : 0, C16 : 0 and summed features containing C16 : 1 ω7c and/or iso-C15 : 0 2-OH and iso-C17 : 1 and/or anteiso-C17 : 1 B. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain was most closely related to Fusibacter paucivorans DSM 12116T (95.5 % sequence similarity). The genome size of strain Q10-2T was 5.0 Mb, with a G+C content of 37.4 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain Q10-2T and F. paucivorans DSM 12116T were 69.1 and 21.8 %, respectively. The combined genotypic and phenotypic data showed that strain Q10-2T represents a novel species of the genus Fusibacter, for which the name Fusibacter ferrireducens sp. nov. is proposed. The type strain is Q10-2T (=MCCC 1A16257T=KCTC 15906T).

Vescimonas gen. nov., Vescimonas coprocola sp. nov., Vescimonas fastidiosa sp. nov., Pusillimonas gen. nov. and Pusillimonas faecalis sp. nov. isolated from human faeces.

Six strains of Gram-stain-negative, obligately anaerobic, non-spore-forming, non-motile rods were isolated from human faeces. Based on phylogenetic characteristics, the six isolates were included in the family Ruminococcaceae, and divided into three groups. The six isolates showed 16S rRNA gene sequence similarity values lower than 96.2 % to the closely related species, Oscillibacter ruminantium GH1T, Oscillibacter valericigenes Sjm18-20T and Dysosmobacter welbiomis J115T. Coherently with the 16S rRNA gene sequence results, the in silico DNA-DNA hybridization and average nucleotide identity values clearly indicated that strains MM35T, MM50T and MM59T belong to different species from the closely related three species. Based on phenotypic features and phylogenetic positions, three novel species, Vescimonas coprocola gen. nov., sp. nov., Vescimonas fastidiosa gen. nov., sp. nov. and Pusillimonas faecalis gen. nov., sp. nov. are proposed. The type strain of V. coprocola is strain MM50T (=JCM 34012T=DSM 111893T). The type strain of V. fastidiosa is strain MM35T (=JCM 34016T=DSM 111899T). The type strain of P. faecalis is strain MM59T (=JCM 34011T=DSM 111669T). The DNA G+C contents estimated according to the whole genomes of strains MM35T, MM50T and MM59T were 56.4, 58.2 and 55.2 mol%, respectively.

Aminipila luticellarii sp. nov., an anaerobic bacterium isolated from the pit mud of strong aromatic Chinese liquor, and emended description of the genus Aminipila.

A novel mesophilic, aerotolerant anaerobic bacterium, designated JN-18T, was isolated from the pit mud of a strong aromatic Chinese liquor. According to a 16S rRNA gene sequence analysis, it had the highest sequence similarity to Aminipila butyrica DSM 103574T (95.69%). The G+C content of its genomic DNA was 43.39 mol%. The cells were Gram-stain-negative, slightly curved rods with flagella. Optimum growth was observed at 37 °C, pH 6.5 and without extra addition of NaCl. Strain JN-18Tutilized amino acids (l-alanine, l-arginine, l-asparagine, l-lysine, l-methionine, l-serine and l-threonine), malate and pyruvate, and used l-arginine and l-lysine to produce acetate, butyrate, H2, and CO2. The major cellular fatty acids of strain JN-18T were C14:0, C16:0 DMA and C18:1 cis-9 DMA. The carbohydrate composition of the cell wall predominantly included galactose, glucose and rhamnose. Based on its phylogenetic, phenotypic, physiological and biochemical characteristics, strain JN-18T was classified as a representative of a novel species within the genus Aminipila, for which the name Aminipila luticellarii sp. nov. is proposed. The type strain is JN-18T (=CCAM 412T=JCM 39126T).

Firmicutes and Blautia in gut microbiota lessened in chronic liver diseases and hepatocellular carcinoma patients: a pilot study.

The gut microbiota system plays a vital role in liver diseases. This study aimed to address the diversity of gut microbiota and its correlations with clinical parameters in healthy individuals, chronic liver disease (CLD), and hepatocellular carcinoma (HCC) patients. Fecal specimens of nine healthy individuals, 11 CLD, and 21 HCC were collected. The diversity of gut microbiota was examined by PCR and Illumina MiSeq sequencing and analyzed using 16S rRNA gene sequencing database. The correlations between gut microbiota and the clinical parameters of participants were also addressed. Compared to healthy individuals, Firmicutes at a phylum level decreased in CLD and HCC patients and Proteobacteria increased (p < 0.05). The composition of Blautia on a genus level in CLD and HCC patients significantly decreased compared to healthy controls (p < 0.05). Firmicutes composition was negatively associated with age and number of males (p < 0.05) and was positively associated with monocytes, high-density lipoprotein cholesterol (HDL-C), and estimated glomerular filtration rate (eGFR) levels (p < 0.05). At a genus level, Blautia composition was negatively associated with cirrhosis, age, and number of males (p < 0.01), while it was positively associated with red blood cells (RBCs), triglycerides, HDL-C, and lymphocyte levels (p < 0.05). Conclusively, there was a significant compositional difference in gut microbiota in CLD and HCC patients compared with healthy subjects. Firmicutes and Blautia in gut microbiota system lessened in CLD and HCC patients. Clinical biochemical parameters have an impact on the diversity of gut microbiota in liver diseases.

Blautia liquoris sp. nov., isolated from the mud in a fermentation cellar used for the production of Chinese strong-flavour liquor.

A novel Gram-positive, non-motile, non-flagellated, strictly anaerobic, non-spore-forming and dumbbell-shaped, coccoid- or chain-shaped bacterium, designated strain LZLJ-3T, was isolated from a mud fermentation cellar which has been used for the production of Chinese strong-flavour liquor for over 100 years. Strain LZLJ-3T grew at 20-40 °C (optimum, 37 °C), at pH 6.0-8.0 (optimum, pH 8.0) and with NaCl concentrations up to 1 % (w/v; optimum, 0 %). Phylogenetic trees established based on 16S rRNA gene sequences showed that strain LZLJ-3T belonged to the genus Blautia of the family Lachnospiraceae, with the highest sequence similarity to Blautia stercoris GAM6-1T (91.7 %) and Blautia faecicola KGMB01111T (91.7 %). Comparative genome analysis showed that the orthologous average nucleotide identity (OrthoANI) and genome-to-genome distance (GGD) values between strain LZLJ-3T and B. stercoris GAM6-1T were respectively 69.1 and 22.9 %; the OrthoANI and GGD values between strain LZLJ-3T and B. faecicola KGMB01111T were respectively 70.86 and 36 % . The DNA G+C content of strain LZLJ-3T genome was 42.1 mol%. The predominant celluar fatty acids (>10 %) of strain LZLJ-3T were C16 : 0 FAME (27.9 %), C14 : 0 FAME (17.6 %) and C16 : 0 DMA (13.0 %). Arabinose, glucose and maltose could be utilized by strain LZLJ-3T as sole carbon sources for growth, with weak utilization of raffinose and l-fucose. API ZYM analysis gave positive reactions with α-galactosidase, ß-galactosidase, α-glucosidase and ß-glucosidase. The major end product of glucose fermentation was acetic acid. Based on the results of phenotypic, genotypic and phylogenetic analyses, strain LZLJ-3T is considered to represent a novel species of Blautia, for which the name Blautia liquoris sp. nov. is proposed. The type strain is LZLJ-3T (=KCTC 25163T=CGMCC 1.5299T=JCM 34225T).

Discovery of novel glycoside hydrolases from C-glycoside-degrading bacteria using sequence similarity network analysis.

C-Glycosides are an important type of natural product with significant bioactivities, and the C-glycosidic bonds of C-glycosides can be cleaved by several intestinal bacteria, as exemplified by the human faeces-derived puerarin-degrading bacterium Dorea strain PUE. However, glycoside hydrolases in these bacteria, which may be involved in the C-glycosidic bond cleavage of C-glycosides, remain largely unknown. In this study, the genomes of the closest phylogenetic neighbours of five puerarin-degrading intestinal bacteria (including Dorea strain PUE) were retrieved, and the protein-coding genes in the genomes were subjected to sequence similarity network (SSN) analysis. Only four clusters of genes were annotated as glycoside hydrolases and observed in the genome of D. longicatena DSM 13814T (the closest phylogenetic neighbour of Dorea strain PUE); therefore, genes from D. longicatena DSM 13814T belonging to these clusters were selected to overexpress recombinant proteins (CG1, CG2, CG3, and CG4) in Escherichia coli BL21(DE3). In vitro assays indicated that CG4 efficiently cleaved the O-glycosidic bond of daidzin and showed moderate ß-D-glucosidase and ß-D-xylosidase activity. CG2 showed weak activity in hydrolyzing daidzin and pNP-ß-D-fucopyranoside, while CG3 was identified as a highly selective and efficient α-glycosidase. Interestingly, CG3 and CG4 could be selectively inhibited by daidzein, explaining their different performance in kinetic studies. Molecular docking studies predicted the molecular determinants of CG2, CG3, and CG4 in substrate selectivity and inhibition propensity. The present study identified three novel and distinctive glycoside hydrolases, highlighting the potential of SSN in the discovery of novel enzymes from genomic data.

Novisyntrophococcus fermenticellae gen. nov., sp. nov., isolated from an anaerobic fermentation cellar of Chinese strong-flavour baijiu.

A Gram-stain-negative, coccus-shaped, obligately anaerobic, non-motile and non-spore-forming bacterium, designated strain JN500902T, was isolated from the mud in a fermentation cellar used continuously over 30 years for Chinese strong-flavour baijiu production. Colonies were white, circular, convex and smooth-edged. Growth was observed at 20-40 °C (optimum, 37 °C), at pH 5.0-10 (optimum, pH 7.5), with 0-2 % (w/v) NaCl and with 0-4 % (v/v) ethanol. The Biolog assay demonstrated positive reactions of strain JN500902T in the metabolism of l-fucose and pyruvate. The predominant cellular fatty acids (>10 %) consisted of C16 : 0 and C14 : 0. The major end metabolites of strain JN500902T were acetic acid and ethanol when incubated anaerobically in liquid reinforced clostridial medium. Acetate was the major organic acid end product. The complete genome size of strain JN500902T was 3 420 321 bp with 3327 identified genes. The G+C content was 43.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain JN500902T with the family Lachnospiraceae, having low sequence similarity (92.8 %) to the nearest type strain, Syntrophococcus sucromutans DSM 3224T and forming a clearly distinct branch. Core genome phylogenetic analysis of the isolate and 134 strains belonging to the family Lachnospiraceae also revealed that strain JN500902T was well-separated from other genera of this family as a monophyletic clade. The average nucleotide identity and amino acid identity values between strain JN500902T and 134 Lachnospiraceae strains were less than 74 and 65 %, respectively. Considering its polyphasic characteristics, strain JN500902T represents a novel genus and species within the family Lachnospiraceae, for which the name Novisyntrophococcus fermenticellae gen. nov., sp. nov. is proposed. The type strain is JN500902T (=CICC 24502T=JCM 33939T).

Conversion of dietary inositol into propionate and acetate by commensal Anaerostipes associates with host health.

We describe the anaerobic conversion of inositol stereoisomers to propionate and acetate by the abundant intestinal genus Anaerostipes. A inositol pathway was elucidated by nuclear magnetic resonance using [13C]-inositols, mass spectrometry and proteogenomic analyses in A. rhamnosivorans, identifying 3-oxoacid CoA transferase as a key enzyme involved in both 3-oxopropionyl-CoA and propionate formation. This pathway also allowed conversion of phytate-derived inositol into propionate as shown with [13C]-phytate in fecal samples amended with A. rhamnosivorans. Metabolic and (meta)genomic analyses explained the adaptation of Anaerostipes spp. to inositol-containing substrates and identified a propionate-production gene cluster to be inversely associated with metabolic biomarkers in (pre)diabetes cohorts. Co-administration of myo-inositol with live A. rhamnosivorans in western-diet fed mice reduced fasting-glucose levels comparing to heat-killed A. rhamnosivorans after 6-weeks treatment. Altogether, these data suggest a potential beneficial role for intestinal Anaerostipes spp. in promoting host health.

A double-blind, 377-subject randomized study identifies Ruminococcus, Coprococcus, Christensenella, and Collinsella as long-term potential key players in the modulation of the gut microbiome of lactose intolerant individuals by galacto-oligosaccharides.

Background. Our recent publication (Chey et al., Nutrients 2020) showed that a 30-day administration of pure galacto-oligosaccharides (GOS) significantly reduced symptoms and altered the fecal microbiome in patients with lactose intolerance (LI). Results. In this addendum, we performed an in-depth analysis of the fecal microbiome of the 377 LI patients randomized to one of two GOS doses (Low, 10-15 grams/day or High, 15-20 grams/day), or placebo in a multi-center, double-blinded, placebo-controlled trial. Sequencing of 16S rRNA amplicons was done on GOS or placebo groups at weeks zero (baseline), four (end of treatment), nine, 16 and 22. Taxa impacted by treatment and subsequent dairy consumption included lactose-fermenting species of Bifidobacterium, Lactobacillus, Lactococcus, and Streptococcus. Increased secondary fermentation microorganisms included Coprococcus and Ruminococcus species, Blautia producta, and Methanobrevibacterium. Finally, tertiary fermenters that use acetate to generate butyrate were also increased, including Faecalibacterium prausnitzii, Roseburia faecis, and C. eutactus. Conclusions. Results confirmed and expanded data on GOS microbiome modulation in LI individuals. Microbiome analysis at 16 and 22 weeks after treatment further suggested relatively long-term benefits when individuals continued consumption of dairy products.

Sulfobacillus harzensis sp. nov., an acidophilic bacterium inhabiting mine tailings from a polymetallic mine.

A mixotrophic and acidophilic bacterial strain BGR 140T was isolated from mine tailings in the Harz Mountains near Goslar, Germany. Cells of BGR 140T were Gram-stain-positive, endospore-forming, motile and rod-shaped. BGR 140T grew aerobically at 25-55 °C (optimum 45 °C) and at pH 1.5-5.0 (optimum pH 3.0). The results of analysis of the 16S rRNA gene sequences indicated that BGR 140T was phylogenetically related to different members of the genus Sulfobacillus, and the sequence identities to Sulfobacillus acidophilus DSM 10332T, Sulfobacillus thermotolerans DSM 17362T, and Sulfobacillus benefaciens DSM 19468T were 94.8, 91.8 and 91.6 %, respectively. Its cell wall peptidoglycan is A1γ, composed of meso-diaminopimelic acid. The respiratory quinone is DMK-6. The major polar lipids were determined to be glycolipid, phospholipid and phosphatidylglycerol. The predominant fatty acid is 11-cycloheptanoyl-undecanoate. The genomic DNA G+C content is 58.2 mol%. On the basis of the results of phenotypic and genomic analyses, it is concluded that strain BGR 140T represents a novel species of the genus Sulfobacillus, for which the name Sulfobacillus harzensis sp. nov. is proposed because of its origin. Its type strain is BGR 140T (=DSM 109850T=JCM 39070T).

Catabacter hongkongensis bacteremia identified by direct metagenomic sequencing of positive blood culture fluid, first case report in the US.

Catabacter hongkongensis, an increasingly recognized bacteria in clinical samples, was identified by direct metagenomic sequencing of positive blood culture fluid from a 55-year-old patient with colonic perforation. The bacteremia was cleared by both antibiotic treatment and surgical intervention. This is the first case report of C. hongkongensis infection in the US.