Capturing the generation and structural transformations of molecular ions.

Molecular ions are ubiquitous and play pivotal roles1-3 in many reactions, particularly in the context of atmospheric and interstellar chemistry4-6. However, their structures and conformational transitions7,8, particularly in the gas phase, are less explored than those of neutral molecules owing to experimental difficulties. A case in point is the halonium ions9-11, whose highly reactive nature and ring strain make them short-lived intermediates that are readily attacked even by weak nucleophiles and thus challenging to isolate or capture before they undergo further reaction. Here we show that mega-electronvolt ultrafast electron diffraction (MeV-UED)12-14, used in conjunction with resonance-enhanced multiphoton ionization, can monitor the formation of 1,3-dibromopropane (DBP) cations and their subsequent structural dynamics forming a halonium ion. We find that the DBP+ cation remains for a substantial duration of 3.6 ps in aptly named 'dark states' that are structurally indistinguishable from the DBP electronic ground state. The structural data, supported by surface-hopping simulations15 and ab initio calculations16, reveal that the cation subsequently decays to iso-DBP+, an unusual intermediate with a four-membered ring containing a loosely bound17,18 bromine atom, and eventually loses the bromine atom and forms a bromonium ion with a three-membered-ring structure19. We anticipate that the approach used here can also be applied to examine the structural dynamics of other molecular ions and thereby deepen our understanding of ion chemistry.

Mapping the emergence of molecular vibrations mediating bond formation.

Fundamental studies of chemical reactions often consider the molecular dynamics along a reaction coordinate using a calculated or suggested potential energy surface1-5. But fully mapping such dynamics experimentally, by following all nuclear motions in a time-resolved manner-that is, the motions of wavepackets-is challenging and has not yet been realized even for the simple stereotypical bimolecular reaction6-8: A-B + C â†’ A + B-C. Here we track the trajectories of these vibrational wavepackets during photoinduced bond formation of the gold trimer complex [Au(CN)2-]3 in an aqueous monomer solution, using femtosecond X-ray liquidography9-12 with X-ray free-electron lasers13,14. In the complex, which forms when three monomers A, B and C cluster together through non-covalent interactions15,16, the distance between A and B is shorter than that between B and C. Tracking the wavepacket in three-dimensional nuclear coordinates reveals that within the first 60 femtoseconds after photoexcitation, a covalent bond forms between A and B to give A-B + C. The second covalent bond, between B and C, subsequently forms within 360 femtoseconds to give a linear and covalently bonded trimer complex A-B-C. The trimer exhibits harmonic vibrations that we map and unambiguously assign to specific normal modes using only the experimental data. In principle, more intense X-rays could visualize the motion not only of highly scattering atoms such as gold but also of lighter atoms such as carbon and nitrogen, which will open the door to the direct tracking of the atomic motions involved in many chemical reactions.

Crif1 deficiency in dopamine neurons triggers early-onset parkinsonism.

Mitochondrial dysfunction has been implicated in Parkinson's Disease (PD) progression; however, the mitochondrial factors underlying the development of PD symptoms remain unclear. One candidate is CR6-interacting factor1 (CRIF1), which controls translation and membrane insertion of 13 mitochondrial proteins involved in oxidative phosphorylation. Here, we found that CRIF1 mRNA and protein expression were significantly reduced in postmortem brains of elderly PD patients compared to normal controls. To evaluate the effect of Crif1 deficiency, we produced mice lacking the Crif1 gene in dopaminergic neurons (DAT-CRIF1-KO mice). From 5 weeks of age, DAT-CRIF1-KO mice began to show decreased dopamine production with progressive neuronal degeneration in the nigral area. At ~10 weeks of age, they developed PD-like behavioral deficits, including gait abnormalities, rigidity, and resting tremor. L-DOPA, a medication used to treat PD, ameliorated these defects at an early stage, although it was ineffective in older mice. Taken together, the observation that CRIF1 expression is reduced in human PD brains and deletion of CRIF1 in dopaminergic neurons leads to early-onset PD with stepwise PD progression support the conclusion that CRIF1-mediated mitochondrial function is important for the survival of dopaminergic neurons.

Sphingobacterium oryzagri sp. nov., isolated from rice paddy soil.

An aerobic, Gram-stain-negative and short rod-shaped bacterial strain, designated M6-31T, was isolated from rice paddy soil sampled in Miryang, Republic of Korea. Growth was observed at 4-35 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-4 % (w/v) NaCl (optimum, 0 % w/v). Phylogenetic analysis based on 16S rRNA gene sequences grouped strain M6-31T with Sphingobacterium bambusae IBFC2009T, Sphingobacterium griseoflavum SCU-B140T and Sphingobacterium solani MLS-26-JM13-11T in the same clade, with the 16S rRNA gene sequence similarities ranging from 95.8 to 96.6 %. A genome-based phylogenetic tree reconstructed by using all publicly available Sphingobacterium genomes placed strain M6-31T with S. bambusae KACC 22910T, 'Sphingobacterium deserti' ACCC 05744T, S. griseoflavum CGMCC 1.12966T and Sphingobacterium paludis CGMCC 1.12801T. Orthologous average nucleotide identity and digital DNA-DNA hybridization values between strain M6-31T and its closely related strains were lower than 74.6 and 22.0 %, respectively. The respiratory quinone was menaquinone-7, and the major polar lipid was phosphatidylethanolamine. The major fatty acids (>10 %) were C15 : 0 iso, C17 : 0 iso 3OH and summed feature 3. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that strain M6-31T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium oryzagri sp. nov. (type strain M6-31T=KACC 22765T=JCM 35893T) is proposed.

Lacticaseibacillus pabuli sp. nov., isolated from fermented cattle feed.

Strain BSF-3MT is a Gram-stain-positive, non-flagellated, facultative anaerobic and rod-shaped bacterium that was isolated from fermented feed collected at a cattle farm in the Daejeon region of the Republic of Korea. It was studied using polyphasic taxonomic methods. Using 16S rRNA gene sequences and the resulting phylogenetic tree, the strain was primarily identified as a member of the genus Lacticaseibacillus. Strain BSF-3MT contained a chromosome of 2.5 Mbp and a plasmid of 33.4 kbp. The G+C content of genomic DNA was 51.3 mol%. Strain BSF-3MT had the highest ortho-average nucleotide identity value of 73.7 % with Lacticaseibacillus songhuajiangensis 7-19T, its closest relative in the phylogenetic tree based on the 16S rRNA gene sequences and the phylogenomic tree based on up-to-date bacterial core genes. Based on the results of a polyphasic taxonomic study, strain BSF-3MT represents a novel species in the genus Lacticaseibacillus, for which the name Lacticaseibacillus pabuli sp. nov. is proposed. The type strain is BSF-3MT (=KACC 23028T=NBRC 116014T).

Microbacterium horticulturae sp. nov., a novel actinobacterium isolated from flowerpot soil.

Strain CJN36-1NT, a Gram-stain-positive, non-flagellated, strictly aerobic and short rod-shaped bacterium, was isolated from flowerpot soil sampled in the Jeonju region of the Republic of Korea. Based on 16S rRNA gene sequences and the resulting phylogenetic tree, the strain belonged to the genus Microbacterium. Strain CJN36-1NT contained a chromosome of 3.6 Mbp with a G+C content of 68.5 mol%. The strain grew at 10-37 °C (optimally at 28 °C), at pH 5.0-8.0 (optimally at pH 8.0), and in the presence of 0-7 % NaCl (w/v; optimally with 0 % NaCl). Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values between strain CJN36-1NT and its closest related species, Microbacterium protaetiae DFW100M-13T, were 82.0, 81.2, and 23.2 %, respectively. We propose naming this novel species Microbacterium horticulturae sp. nov., with CJN36-1NT (=KACC 23027T=NBRC 116065T) as the type strain.

Antiviral Potential of Fucoxanthin, an Edible Carotenoid Purified from Sargassum siliquastrum, against Zika Virus.

Considering the lack of antiviral drugs worldwide, we investigated the antiviral potential of fucoxanthin, an edible carotenoid purified from Sargassum siliquastrum, against zika virus (ZIKV) infection. The antiviral activity of fucoxanthin was assessed in ZIKV-infected Vero E6 cells, and the relevant structural characteristics were confirmed using molecular docking and molecular dynamics (MD) simulation. Fucoxanthin decreased the infectious viral particles and nonstructural protein (NS)1 mRNA expression levels at concentrations of 12.5, 25, and 50 µM in ZIKV-infected cells. Fucoxanthin also decreased the increased mRNA levels of interferon-induced proteins with tetratricopeptide repeat 1 and 2 in ZIKV-infected cells. Molecular docking simulations revealed that fucoxanthin binds to three main ZIKV proteins, including the envelope protein, NS3, and RNA-dependent RNA polymerase (RdRp), with binding energies of -151.449, -303.478, and -290.919 kcal/mol, respectively. The complex of fucoxanthin with RdRp was more stable than RdRp protein alone based on MD simulation. Further, fucoxanthin bonded to the three proteins via repeated formation and disappearance of hydrogen bonds. Overall, fucoxanthin exerts antiviral potential against ZIKV by affecting its three main proteins in a concentration-dependent manner. Thus, fucoxanthin isolated from S. siliquastrum is a potential candidate for treating zika virus infections.

Effects of a Combination of Polynucleotide and Hyaluronic Acid for Treating Osteoarthritis.

Knee osteoarthritis (OA), an age-related degenerative disease characterized by severe pain and disability, is treated using polynucleotides (PNs) and hyaluronic acid (HA). The intra-articular (IA) injection of HA has been studied extensively in both animal models and in humans; however, the efficacy and mechanisms of action remain unclear. In addition, there has been a paucity of research regarding the use of PN alone or in combination with HA in OA. To investigate the effect of the combined injection of PN and HA in vivo, pathological and behavioral changes were assessed in an OA model. Anterior cruciate ligament transection and medial meniscectomy were performed in Sprague-Dawley rats to create the OA animal model. The locomotor activity improved following PNHA injection, while the OARSI grade improved in the medial tibia and femur. In mild OA, TNFα levels decreased histologically in the PN, HA, and PNHA groups but only the PNHA group showed behavioral improvement in terms of distance. In conclusion, PNHA exhibited anti-inflammatory effects during OA progression and improved locomotor activity regardless of the OARSI grade.

LIN28A loss of function is associated with Parkinson's disease pathogenesis.

Parkinson's disease (PD) is neurodegenerative movement disorder characterized by degeneration of midbrain-type dopamine (mDA) neurons in the substantia nigra (SN). The RNA-binding protein Lin28 plays a role in neuronal stem cell development and neuronal differentiation. In this study, we reveal that Lin28 conditional knockout (cKO) mice show degeneration of mDA neurons in the SN, as well as PD-related behavioral deficits. We identify a loss-of-function variant of LIN28A (R192G substitution) in two early-onset PD patients. Using an isogenic human embryonic stem cell (hESC)/human induced pluripotent stem cell (hiPSC)-based disease model, we find that the Lin28 R192G variant leads to developmental defects and PD-related phenotypes in mDA neuronal cells that can be rescued by expression of wild-type Lin28A. Cell transplantation experiments in PD model rats show that correction of the LIN28A variant in the donor patient (pt)-hiPSCs leads to improved behavioral phenotypes. Our data link LIN28A to PD pathogenesis and suggest future personalized medicine targeting this variant in patients.

Glycosylation generates an efficacious and immunogenic vaccine against H7N9 influenza virus.

Zoonotic avian influenza viruses pose severe health threats to humans. Of several viral subtypes reported, the low pathogenic avian influenza H7N9 virus has since February 2013 caused more than 1,500 cases of human infection with an almost 40% case-fatality rate. Vaccination of poultry appears to reduce human infections. However, the emergence of highly pathogenic strains has increased concerns about H7N9 pandemics. To develop an efficacious H7N9 human vaccine, we designed vaccine viruses by changing the patterns of N-linked glycosylation (NLG) on the viral hemagglutinin (HA) protein based on evolutionary patterns of H7 HA NLG changes. Notably, a virus in which 2 NLG modifications were added to HA showed higher growth rates in cell culture and elicited more cross-reactive antibodies than did other vaccine viruses with no change in the viral antigenicity. Developed into an inactivated vaccine formulation, the vaccine virus with 2 HA NLG additions exhibited much better protective efficacy against lethal viral challenge in mice than did a vaccine candidate with wild-type (WT) HA by reducing viral replication in the lungs. In a ferret model, the 2 NLG-added vaccine viruses also induced hemagglutination-inhibiting antibodies and significantly suppressed viral replication in the upper and lower respiratory tracts compared with the WT HA vaccines. In a mode of action study, the HA NLG modification appeared to increase HA protein contents incorporated into viral particles, which would be successfully translated to improve vaccine efficacy. These results suggest the strong potential of HA NLG modifications in designing avian influenza vaccines.

Melaminivora suipulveris sp. nov., isolated from pigpen dust.

A bacterial strain designated SC2-9T was isolated from the dust collector of a pigpen located in Wanju-gun, Jeollabuk-do, Republic of Korea. Cells were strictly aerobic, Gram-stain-negative, flagellated and rod-shaped. The strain was catalase- and oxidase-positive, and grew optimally 28-30 °C, pH 8.0 and 0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed 99.1 and 98.3 % similarities to Melaminivora jejuensis KBB12T and Melaminivora alkalimesophila CY1T, and revealing less than 97 % similarity to other validly named species. The genomic DNA G+C content of strain SC2-9T was 68.2 %. The orthologous average nucleotide identity and dDDH values of strain SC2-9T with the closest species Melaminivora jejuensis KCTC 32230T were 85.6 and 29.3 %, respectively. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminolipids and one unidentified lipid. The major fatty acids (>10 %) were summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), C16 : 0 and summed feature 8 (C18 : 1 ω6c and/ or C18 : 1 ω7c). The predominant isoprenoid quinone was ubiquinone-8. Based on phenotypic, chemotaxonomic and phylogenetic data, strain SC2-9T should be assigned as a novel species of the genus Melaminivora, for which the name Melaminivora suipulveris sp. nov. is proposed. The type strain is SC2-9T (=KACC 19310T=NBRC 113103T).

Agromyces larvae sp. nov., a novel actinobacterium isolated from gut of larvae of Protaetia brevitarsis seulensis.

A novel actinobacterium strain, designated CFWR-12T, was isolated from the larval gut of Protaetia brevitarsis seulensis grown at the National Institute of Agricultural Sciences, Wanju-gun, Republic of Korea, and its taxonomic position was evaluated. Strain CFWR-12T was aerobic, Gram-stain-positive and non-motile. Growth occurred at 10-40 °C, pH 6.0-9.0 and 0-4 % (w/v) NaCl, with optimal growth at 28-30 °C, pH 7.0 and in the absence of NaCl. Strain CFWR-12T showed high 16S rRNA gene sequence similarity to Agromyces intestinalis KACC 19306T (99.0 %) and Agromyces protaetiae FW100M-8T (97.9 %). The genome sequence of strain CFWR-12T was 4.01 Mb in size with a high G+C content of 71.2 mol%. The values of average nucleotide identity and digital DNA-DNA hybridization between strain CFWR-12T and A. intestinalis KACC 19306T were 89.8 and 39.1 %, respectively, which were the highest among the closely related Agromyces species. The predominant cellular fatty acids (>10 %) were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0, and the major respiratory quinones (>10 %) were MK-11 and MK-12. The polar lipids were composed of diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid and an unidentified lipid while the peptidoglycan type was identified to be B1. Data based on chemotaxonomic, phylogenetic, phenotypic and genomic evidence demonstrated that strain CFWR-12T represents a novel species of the genus Agromyces, for which the name Agromyces larvae sp. nov. is proposed. The type strain is strain CFWR-12T (=KACC 19307T= NBRC 113047T).

Leucobacter allii sp. nov. and Leucobacter rhizosphaerae sp. nov., isolated from rhizospheres of onion and garlic, respectively.

Three bacterial strains, H21R-40T and H21R-36 from garlic (Allium sativum) and H25R-14T from onion (Allium cepa), were isolated from plant rhizospheres sampled in the Republic of Korea. Results of 16S rRNA gene sequence analysis revealed the highest sequence similarity of strain H21R-40T to Leucobacter celer subsp. astrifaciens CBX151T (97.3 %) and Leucobacter triazinivorans JW-1T (97.2 %), and strain H25R-14T to Leucobacter insecticola HDW9BT (98.8 %) and Leucobacter humi Re6T (98.4 %), while the sequence similarity between strains H21R-40T and H21R-36 was 99.8 %. According to the phylogenomic tree, strains H21R-40T with H21R-36 formed an independent clade separable from other Leucobacter species within the genus Leucobacter and strain H25R-14T clustered with Leucobacter insecticola HDW9BT, Leucobacter coleopterorum HDW9AT and Leucobacter viscericola HDW9CT. Strains H21R-40T and H21R-36 had orthologous average nucleotide identity (OrthoANI) and digital DNA-DNA hybridization (dDDH) values (98.1 % and 86.9 %, respectively) higher than the threshold ranges for species delineation (95-96 % and 70 %, respectively). The OrthoANI and dDDH values between two strains (H21R-40T and H25R-14T) and the type strains of species of the genus Leucobacter were lower than 81 and 24 %, respectively. The peptidoglycan type of three strains was type B1. The major menaquinones and major polar lipids of the strains were MK-11 and MK-10, and diphosphatidylglycerol, phatidylglycerol and an unidentified glycolipid, respectively. The major fatty acids (more than 10 % of the total fatty acids) of strains H21R-40T and H21R-36 were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0, and those of strain H25R-14T were anteiso-C15 : 0 and iso-C16 : 0. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that the strains represent two novel species of the genus Leucobacter, named Leucobacter allii sp. nov. (H21R-40T and H21R-36) and Leucobacter rhizosphaerae sp. nov. (H25R-14T). The respective type strains are H21R-40T (=DSM 114348T=JCM 35241T=KACC 21839T=NBRC 115481T) and H25R-14T (=DSM 114346T=JCM 35239T=KACC 21837T=NBRC 115479T).

Brevibacillus ruminantium sp. nov., isolated from cow faeces.

An aerobic, Gram-stain-positive, rod-shaped, endospore-forming bacterial strain, designated BB3-R1T, was isolated from cow faeces sampled in Daejeon, Republic of Korea. Growth was observed at 25-45 °C (optimum, 35-40 °C) and pH 7.0-9.0 (optimum, pH 8.0), with up to 3 % (w/v) NaCl (optimum, 0 % NaCl). blast analysis of 16S rRNA gene sequences revealed the highest sequence similarity of strain BB3-R1T to Brevibacillus borstelensis NRRL NRS-818T (98.8 %) followed by Brevibacillus panacihumi JCM 15085T (97.5 %). According to 16S rRNA gene and whole-genome based phylogenetic trees, strain BB3-R1T clustered with Brevibacillus composti FJAT-54423T and B. borstelensis NRRL NRS-818T. OrthoANI and dDDH values of strain BB3-R1T with the closely related strains were lower than 77.5 and 26.8 %, respectively. The major menaquinones and polar lipids of the strain were MK-7 and phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, respectively. The major fatty acids (>10 %) were C14 : 0 iso, C15 : 0 iso, C15 : 0 anteiso and C16 : 1 ω7c alcohol. The cell-wall peptidoglycan contained cross-linked meso-diaminopimelic acid (type A1 gamma). The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that the strain represents a novel species of the genus Brevibacillus, for which the name Brevibacillus ruminantium sp. nov. (type strain BB3-R1T=KACC 22663T=NBRC 115962T) is proposed.

Frateuria soli sp. nov. and Frateuria edaphi sp. nov., isolated from greenhouse soil.

Two bacterial strains, designated 5GH9-11T and 5GH9-34T, were isolated from greenhouse soil sampled in Wanju-gun, Jeollabuk-do, Republic of Korea. Both strains formed yellow colonies and were aerobic, rod-shaped and flagellated. The 16S rRNA gene sequence similarity between 5GH9-11T and 5GH9-34T was 98.6 %. Strain 5GH9-11T showed the highest sequence similarities to Dyella thiooxydans ATSB10T (98.1 %) and Frateuria aurantia DSM 6220T (97.7 %) while strain 5GH9-34T revealed the highest sequence similarity to F. aurantia DSM 6220T (98.3 %) and D. thiooxydans ATSB10T (98.3 %). Phylogenetic analysis on the basis of the 16S rRNA gene sequence showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with Frateuria flava MAH-13T and Frateuria terrea NBRC 104236T. The phylogenomic tree also showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with F. terrea DSM 26515T and F. flava MAH-13T. Strain 5GH9-11T showed the highest orthologous average nucleotide identity (OrthoANI; 88.5 %) and digital DNA-DNA hybridization (dDDH) values (35.5 %) with F. flava MAH-13T, and strain 5GH9-34T revealed highest OrthoANI (88.1 %) and dDDH (34.2 %) values with F. flava MAH-13T. The orthoANI and dDDH values between strain 5GH9-11T and 5GH9-34T were 87.7 and 33.9 %, respectively. Their major respiratory quinone was ubiquinone 8, and the major cellular fatty acids were iso-C16 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl) and iso-C15 : 0. The major polar lipids of both strains were composed of large or moderate amounts of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminolipid and an unidentified aminophospholipid. Based on these data, strains 5GH9-11T and 5GH9-34T should represent two independent novel species of Frateuria, for which the names Frateuria soli sp. nov. (type strain 5GH9-11T=KACC 16943T=JCM 35197T) and Frateuria edaphi sp. nov. (type strain 5GH9-34T=KACC 16945T=JCM 35198T) are proposed.

Five novel Hymenobacter species isolated from air: Hymenobacter cellulosilyticus sp. nov., Hymenobacter cellulosivorans sp. nov., Hymenobacter aerilatus sp. nov., Hymenobacter sublimis sp. nov. and Hymenobacter volaticus sp. nov.

Five Hymenobacter strains isolated from air samples collected from the Suwon and Jeju regions of the Republic of Korea were studied using polyphasic taxonomic methods. Using 16S rRNA gene sequences and the resulting phylogenetic tree, the strains were primarily identified as members of the genus Hymenobacter. Digital DNA-DNA hybridization values and average nucleotide identities values for species delineation (70 and 95-96 %, respectively) between the five strains and their nearest type strains indicated that each strain represented a novel species. All strains were aerobic, Gram-stain-negative, mesophilic, rod-shaped and catalase- and oxidase-positive, with red to pink coloured colonies. The genome sizes of the five strains varied from 4.8 to 7.1 Mb and their G+C contents were between 54.1 and 59.4 mol%. Based on their phenotypic, chemotaxonomic and genotypic characteristics, we propose to classify these isolates into five novel species within the genus Hymenobacter for which we propose the names, Hymenobacter cellulosilyticus sp. nov., Hymenobacter cellulosivorans sp. nov., Hymenobacter aerilatus sp. nov., Hymenobacter sublimis sp. nov. and Hymenobacter volaticus sp. nov., with strains 5116 S-3T (=KACC 21925T=JCM 35216T), 5116 S-27T (=KACC 21926T=JCM 35217T), 5413 J-13T (=KACC 21928T=JCM 35219T), 5516 S-25T (=KACC 21931T=JCM 35222T) and 5420 S-77T (=KACC 21932T=JCM 35223T) as the type strains, respectively.

Halobacillus salinarum sp. nov., Halobacillus shinanisalinarum sp. nov. and Halobacillus amylolyticus sp. nov., isolated from saltern soil.

Three bacterial strains, designated SSBR10-3T, SSTM10-2T and SSHM10-5T, were isolated from saltern soil sampled in Jeollanam-do, Republic of Korea. Cells were aerobic, Gram-stain-positive, flagellated and rod-shaped. The strains grew optimally at 28°C and at pH 7.0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains SSBR10-3T, SSTM10-2T and SSHM10-5T were placed within the genus Halobacillus, showing the highest similarity to Halobacillus alkaliphilus FP5T (98.6 %), 'Halobacillus ihumii' Marseille-Q1234T (98.5 %) and Halobacillus locisalis MSS-155T (98.6 %), respectively. The genomic similarity values between strains SSBR10-3T, SSTM10-2T and SSHM10-5T and their related species were 17.6-22.6 % for digital DNA-DNA hybridization (dDDH) and 69.6-78.5 % for orthologous average nucleotide identity (OrthoANI), which were lower than the thresholds recommended for species delineation. The dDDH and OrthoANI values among the three strains were below 38.3 and 89.4 %, respectively. Besides the differences in genomic features, strains SSBR10-3T, SSTM10-2T and SSHM10-5T were distinct from each other and from members of the genus in terms of phenotypic traits related to substrate assimilation. The cell-wall peptidoglycan contained meso-diaminopimelic acid, the major fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0, and the predominant menaquinone was MK-7 for all three strains. Diphosphatidylglycerol, phosphatidylglycerol and an unidentified phospholipid were present in their polar lipid profiles. Based on a polyphasic approach incorporating genomic data, strains SSBR10-3T, SSTM10-2T and SSHM10-5T represent novel species, for which the names Halobacillus salinarum sp. nov. (SSBR10-3T=DSM 114353T=KACC 21935T=NBRC 115504T), Halobacillus shinanisalinarum sp. nov. (SSTM10-2T=DSM 114354T=KACC 21936T=NBRC 115505T) and Halobacillus amylolyticus sp. nov. (SSHM10-5T=DSM 114355T= KACC 21937T=NBRC 115506T) are proposed.

Gracilibacillus salinarum sp. nov. and Gracilibacillus caseinilyticus sp. nov., halotolerant bacteria isolated from a saltern environment.

Two aerobic, Gram-stain-positive, spore-forming motile bacterial strains, designated SSPM10-3T and SSWR10-1T, were isolated from salterns in Jeollanam province of South Korea. Both strains were halotolerant and grew well in 5 % NaCl but not in 20 and 25% NaCl, respectively. Optimal growth was observed with 5 % NaCl, at 30 °C and at pH 7.0-8.0. On the basis of the results of phylogenetic analysis using 16S rRNA gene sequence, both the strains were placed within the genus Gracilibacillus with Gracilibacillus massiliensis (98.65 % similarity) as their nearest neighbour. Menaquinone-7 (MK-7) (97 %) was the major isoprenoid quinone in both strains and major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. Orthologous average nucleotide identity with usearch (OrthoANIu) and digital DNA-DNA hybridisation (dDDH) percentage comparison indicated that SSPM10-3T and SSWR10-1T exhibited highest similarity with G. massiliensis Awa-1T at 74.27 % and 21.0 and 74.23 % and 20.0 %, respectively. The DNA G+C contents of the strains were 39.1 % (SSPM10-3T) and 38.5 % (SSWR10-1T). Members of the genus Gracilibacillus, both strains were distinct from each other with respect to their ability to produce urease, ß-glucosidase, assimilation of inulin and methyl-α-d-glucopyranoside and degradation of casein. Compared with each other, ANI and d4 dDDH calculations were only 88.2 % and 36.3 %, well below the cut-off values for species delineation for each index. On the basis of their phenotypic, physiological, biochemical and phylogenetic characteristics,SSPM10-3T and SSWR10-1T represent distinct novel species for which names Gracilibacillus salinarum SSPM10-3T and Gracilibacillus caseinilyticus SSWR10-1T are proposed. The type strains are SSPM10-3T (=KACC 21933T =NBRC 115502T) and SSWR10-1T (=KACC 21934T =NBRC 115503T).

Spirosoma oryzicola sp. nov., isolated from dried rice husk.

Strain RHs26T is an aerobic, Gram-stain-negative, non-flagellated and rod- or filamentous-shaped (1.0-1.1×2.3-50 µm) bacterium that was isolated from dried rice husk. It was positive for oxidase and catalase, hydrolysed starch and Tween 80, and weakly hydrolysed CM-cellulose. The strain grew at temperatures between 10 and 37 °C (optimum, 28 °C), in 0-1 % NaCl (optimum, 0 %) and at pH 6.0-9.0 (optimum, pH 7.0-8.0). The predominant membrane fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 1 ω5c, iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and two unidentified lipids. The predominant quinone was menaquinone MK-7. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHs26T belongs to the genus Spirosoma, presenting the highest sequence similarity to Spirosoma agri S7-3-3T (95.8 %). The genomic DNA G+C content of strain RHs26T was 49.5 %. Strain RHs26T showed the highest orthologous average nucleotide identity (OrthoANI) and digital DNA-DNA hybridization (dDDH) values of 76.4 % and 20.0 % with S. agri KCTC 52727T while sharing OrthoANI and dDDH values of 74.6 % and 19.2 % with Spirosoma terrae KCTC 52035T, the closest relative in the phylogenomic tree. Based on the results of a polyphasic taxonomic study, strain RHs26T represents a novel species in the genus Spirosoma, for which the name Spirosoma oryzicola sp. nov. is proposed. The type strain is RHs26T (=JCM 35224T=KACC 17318T).

Incidence of colonoscopy-related perforation and risk factors for poor outcomes: 3-year results from a prospective, multicenter registry (with videos).

BACKGROUND AND AIMS: Perforation is a life-threatening adverse event of colonoscopy that often requires hospitalization and surgery. We aimed to prospectively assess the incidence of colonoscopy-related perforation in a multicenter registry and to analyze the clinical factors associated with poor clinical outcomes. METHODS: This prospective observational study was conducted at six tertiary referral hospitals between 2017 and 2020, and included patients with colonic perforation after colonoscopy. Poor clinical outcomes were defined as mortality, surgery, and prolonged hospitalization (> 13 days). Logistic regression was used to identify factors associated with poor clinical outcomes. RESULTS: Among 84,673 patients undergoing colonoscopy, 56 had colon perforation (0.66/1000, 95% confidence interval [CI] 0.51-0.86). Perforation occurred in 12 of 63,602 diagnostic colonoscopies (0.19/1000, 95% CI 0.11-0.33) and 44 of 21,071 therapeutic colonoscopies (2.09/1000, 95% CI 1.55-2.81). Of these, 15 (26.8%) patients underwent surgery, and 25 (44.6%) patients had a prolonged hospital stay. One patient (1.8%) died after perforation from a diagnostic colonoscopy. In the multivariate analysis, diagnostic colonoscopy (adjusted odds ratio [aOR] 196.43, p = 0.025) and abdominal rebound tenderness (aOR 17.82, p = 0.012) were independent risk factors for surgical treatment. The location of the sigmoid colon (aOR 18.57, p = 0.048), delayed recognition (aOR 187.71, p = 0.008), and abdominal tenderness (aOR 63.20, p = 0.017) were independent risk factors for prolonged hospitalization. CONCLUSIONS: This prospective study demonstrated that the incidence of colonoscopy-related perforation was 0.66/1000. The incidence rate was higher in therapeutic colonoscopy, whereas the risk for undergoing surgery was higher in patients undergoing diagnostic colonoscopy. Colonoscopy indication (diagnostic vs. therapeutic), physical signs, the location of the sigmoid perforation, and delayed recognition were independent risk factors for poor clinical outcomes in colonoscopy-related perforation.