Description of an anaerobic actinobacterium, Kribbibacterium absianum gen. nov., sp. nov., a new member of the novel family Kribbibacteriaceae fam. nov., and reclassification of the genera Granulimonas and Leptogranulimonas

Two rod-shaped, obligate anaerobic, Gram-stain-positive bacteria isolated from the pig faeces were designated YH-ols2216 and YH-ols2217T. Analysis of 16S rRNA gene sequences revealed that these isolates were most related to the members of the family Atopobiaceae, within the order Coriobacteriales, and Granulimonas faecalis KCTC 25474T with 92.0 and 92.5% similarities, respectively. The 16S rRNA gene sequence similarity within isolates was 99.9 %; and those between isolates YH-ols2216 and YH-ols2217T, and Atopobium minutum DSM 20586T, the type species of the type genus Atopobium within the family Atopobiaceae, were 88.5 and 88.7 %, respectively. Those between isolates and Coriobacterium glomerans PW2T, the type species of the type genus Coriobacterium within the family Coriobacteriaceae, were 88.7 and 89.1 %, respectively. The multi-locus sequence tree revealed that the isolates, alongside the genera Granulimonas and Leptogranulimonas, formed a distinct cluster between the families Atopobiaceae and Coriobacteriaceae. The average nucleotide identities and digital DNA-DNA hybridization values for the isolates and their most closely related strains ranged from 67.7 to 76.2 % and from 18.4 to 23.3 %, respectively. The main cellular fatty acids of the isolates were C18 : 0 DMA, C18 : 1  ω9c, C18 : 0 12OH, C18 : 0, and C16 : 0. The cell wall contained the peptidoglycan meso-diaminopimelic acid. Lactate was the main end-product of the isolates. The major polar lipids of isolate YH-ols2217T were aminophospholipid, aminolipids, and lipids. Menaquinones were not identified in the cells of the isolates. The DNA G+C contents of isolates YH-ols2216 and YH-ols2217T were 67.5 and 67.6 mol%, respectively. Considering these chemotaxonomic, phenotypic, and phylogenetic properties, Kribbibacteriaceae fam. nov. is proposed within the order Coriobacteriales. YH-ols2216 (=KCTC 25708=NBRC 116429) and YH-ols2217T (=KCTC 25709T=NBRC 116430T) represent a novel taxon within this new family and the name Kribbibacterium absianum gen. nov., sp. nov. is proposed. In addition, the genera Granulimonas and Leptogranulimonas are transferred to the family Kribbibacteriaceae fam. nov.

Aerococcus kribbianus sp. nov., a facultatively anaerobic bacterium isolated from pig faeces

Two cocci-shaped, facultatively anaerobic, Gram-positive bacteria isolated from the faeces of a pig were designated as strains YH-aer221T and YH-aer222. Analysis of the 16S rRNA gene sequences revealed that the isolates were most closely related to Aerococcus suis JCM 18035T with 96.6 % similarity. The multi-locus sequence tree revealed that the isolates formed a sub-cluster adjacent to A. suis JCM 18035T. The average nucleotide identity values for the isolates and their most closely related strains were 71.8 and 71.7 %, respectively; and the digital DNA-DNA hybridization values for the isolates and their most closely related strains were 25.6 and 25.5 %, respectively. The main fatty acids were C18 : 1ω9c, C16 : 0 and C18 : 0. The cell wall contained the meso-diaminopimelic acid-based peptidoglycan. The two isolates shared the same metabolic pathways. Isolates YH-aer221T and YH-aer222 harboured the same CRISPR array with 33 and 46 spacers, respectively. Single-genome vs. metagenome analysis showed that the genomes of the isolates were not found in the available metagenome database. Given their chemotaxonomic, phenotypic and phylogenetic properties, YH-aer221T (= KCTC 25571T=JCM 35699T) and YH-aer222 (=KCTC 25573=JCM 35700) represent a novel taxon. The name Aerococcus kribbianus sp. nov. is proposed.

Description of Fusibacillus kribbianus gen. nov., sp. nov., a fusiform anaerobe isolated from pig feces

OBJECTIVE

The family Lachnospiraceae is affiliated with the order Clostridiales and was originally contained within Clostridial cluster XIVa. The members of Lachnospiraceae inhabiting the gut comprise the chemoorganotrophic genera, generating sundry short-chain fatty acids to supply energy to the host, and are considered to be related to obesity and gut health.

METHODS

The polyphasic taxonomic approach was used to characterize the isolate YH-rum2234T. A detailed metabolic analysis was conducted to compare the novel isolate with related strains within the family Lachnospiraceae.

RESULTS

A fusiform, obligately anaerobic, Gram-stain-negative bacterium, YH-rum2234T, was isolated from pig feces. Analysis of the 16S rRNA gene sequence revealed that the similarities between the isolate and the familiarly interrelated strain Lientehia hominis KCTC 25345T was 94.3%. The average nucleotide identities and genome-to-genome distances of YH-rum2234T and its closely related strains were below 85.5% and 32.5%, respectively. The G + C content of the genomic DNA was 49.2 mol%. The main fatty acids were C16:0, C14:0, and C14:0 DMA. The major polar lipids were aminophospholipids. The cell wall did not contain the peptidoglycan meso-diaminopimelic acid.

CONCLUSION

Given the chemotaxonomic, phenotypic, and phylogenetic properties, YH-rum2234T (=KCTC 25710T = DSMZ 116041T) represents a new genus and species in the family Lachnospiraceae. Fusibacillus kribbianus gen. nov., sp. nov. is the proposed name.

The novel immunobiotic Clostridium butyricum S-45-5 displays broad-spectrum antiviral activity in vitro and in vivo by inducing immune modulation

Clostridium butyricum is known as a probiotic butyric acid bacterium that can improve the intestinal environment. In this study, we isolated a new strain of C. butyricum from infant feces and evaluated its physiological characteristics and antiviral efficacy by modulating the innate immune responses in vitro and in vivo. The isolated C. butyricum S-45-5 showed typical characteristics of C. butyricum including bile acid resistance, antibacterial ability, and growth promotion of various lactic acid bacteria. As an antiviral effect, C. butyricum S-45-5 markedly reduced the replication of influenza A virus (PR8), Newcastle Disease Virus (NDV), and Herpes Simplex Virus (HSV) in RAW264.7 cells in vitro. This suppression can be explained by the induction of antiviral state in cells by the induction of antiviral, IFN-related genes and secretion of IFNs and pro-inflammatory cytokines. In vivo, oral administration of C. butyricum S-45-5 exhibited prophylactic effects on BALB/c mice against fatal doses of highly pathogenic mouse-adapted influenza A subtypes (H1N1, H3N2, and H9N2). Before challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed increased levels of IFN-β, IFN-γ, IL-6, and IL-12 in serum, the small intestine, and bronchoalveolar lavage fluid (BALF), which correlated with observed prophylactic effects. Interestingly, after challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed reduced levels of pro-inflammatory cytokines and relatively higher levels of anti-inflammatory cytokines at day 7 post-infection. Taken together, these findings suggest that C. butyricum S-45-5 plays an antiviral role in vitro and in vivo by inducing an antiviral state and affects immune modulation to alleviate local and systemic inflammatory responses caused by influenza virus infection. Our study provides the beneficial effects of the new C. butyricum S-45-5 with antiviral effects as a probiotic.

APSIC dental infection prevention and control (IPC) guidelines

BACKGROUND

The Asia Pacific Society of Infection Control launched the Infection Prevention and Control Guidelines in July 2022. This document describes the guidelines and recommendations for safe practices in dental setting. It aims to highlight practical recommendations in a concise format designed to assist dental facilities at Asia Pacific region in achieving high standards in infection prevention and control practices, staff and patient safety.

METHOD

The guidelines were developed by an appointed workgroup comprising experts in the Asia Pacific region, following reviews of previously published international guidelines and recommendations relevant to each section.

RESULTS

It recommends standard precautions as a minimal set of preventive measures to protect staff and prevent cross transmission. Surgical aseptic technique is recommended when procedures are technically complex and longer in duration. Only trained staff are eligible to conduct reprocessing of dental instruments. The design, layout of the dental facility are important factors for successful infection prevention. The facility should also have a Pandemic Preparedness Plan.

CONCLUSIONS

Dental facilities should aim for excellence in infection prevention and control practices as this is part of patient safety. The guidelines that come with a checklist help dental facilities to identify gaps for improvement to reach this goal.

Lacticaseibacillus parakribbianus sp. nov., isolated from a pig farm faeces dump

A lactic acid bacterium isolated from pig faeces was characterized using a polyphasic approach. The strain was Gram-stain-positive, rod-shaped, and facultative anaerobic. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the isolate belonged to the genus Lacticaseibacillus. The multi-locus sequence tree revealed that the strain formed a sub-cluster adjacent to Lacticaseibacillus kribbianus. The main fatty acids were C_16 : 0 and C_18 : 1ω9c. The average nucleotide identity value, average amino acid identity, and genome-to-genome distance for YH-lacS6^T and its most closely related strain, L. kribbianus, were 85.4, 85.2 and 29.2 %, respectively. The G+C content of the genomic DNA was 61.6 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, aminophospholipids and phospholipids. The cell-wall peptidoglycan did not contain meso-diaminopimelic acid. Thus, YH-lacS6^T (=KCTC 21186^T=JCM 34954^T) represents a novel species. The name Lacticaseibacillus parakribbianus sp. nov. is proposed.

Lacticaseibacillus kribbianus sp. nov., isolated from pig farm faeces dump

A lactic acid bacteria isolated from pig faeces was characterized using a polyphasic approach. Cells of the strain were Gram-stain-positive, rod-shaped and facultative anaerobic. Phylogenetic analysis of 16S rRNA gene sequence indicated that the isolate belonged to the genus Lacticaseibacillus; however, the similarity to other homologues within the genus was <98 %. Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster adjacent to Lacticaseibacillus absianus and Lacticaseibacillus daqingensis. The main fatty acids of the strain is the C_18 : 1ω9c and C_16 : 0. The G+C content of the genomic DNA was 62.8 mol %. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, aminophospholipids and phospholipids. The cell-wall peptidoglycan did not contain meso-diaminopimelic acid. Thus, YH-lac21^T (=KCTC 21185=JCM 34953) represents a novel species. The name Lacticaseibacillus kribbianus sp. nov. is proposed.

P02.01.B The telomere maintenance mechanism spectrum and its dynamics in gliomas

The activation of the telomere maintenance mechanism (TMM) is one of the critical drivers of cancer cell immortality. In gliomas, TERT expression and TERT promoter mutation are considered to reliably indicate telomerase activation, while ATRX mutation indicates alternative lengthening of telomeres (ALT). However, these relationships have not been extensively validated in tumor tissues. Here, we show through the direct measurement of telomerase activity and ALT in a large set of glioma samples that the TMM in glioma cannot be defined in the dichotomy of telomerase activity and ALT, regardless of TERT expression, TERT promoter mutation and ATRX mutation. Moreover, we observed that a considerable proportion of gliomas lack both telomerase activity and ALT (Neither group). And this Neither group exhibited evidence of slow growth potential. From a set of longitudinal samples from a separate cohort of glioma patients, we discovered that the TMM is not fixed but changes with glioma progression. Collectively, these results suggest that the TMM is a dynamic entity and that reflects the plasticity of the oncogenic biological status of tumor cells and that the TMM should be defined by the direct measurement of telomerase enzyme activity and evidence of ALT.

Characterization of rhodanine derivatives as potential disease-modifying drugs for experimental mouse osteoarthritis

OBJECTIVE

This study was performed to characterize selected rhodanine derivatives as potential preclinical disease-modifying drugs for experimental osteoarthritis (OA) in mice.

METHODS

Three rhodanine derivatives, designated rhodanine (R)-501, R-502, and R-503, were selected as candidate OA disease-modifying drugs. Their effects were evaluated by intra-articular (IA) injection in OA mouse models induced by DMM (destabilization of the medial meniscus) or adenoviral overexpression in joint tissues of hypoxia-inducible factor (HIF)-2α or zinc importer ZIP8. The regulatory mechanisms impacted by the rhodanine derivatives were examined in primary-culture chondrocytes and fibroblast-like synoviocytes (FLS).

RESULTS

All three rhodanine derivatives inhibited OA development caused by DMM or overexpression of HIF-2α or ZIP8. Compared to vehicle-treated group, for example, IA injection of R-501 in DMM-operated mice reduced median OARSI grade from 3.78 (IQR 3.00-5.00) to 1.89 (IQR 0.94-2.00, P = 0.0001). R-502 and R-503 also reduced from 3.67 (IQR 2.11-4.56) to 2.00 (IQR 1.00-2.00, P = 0.0030) and 2.00 (IQR 1.83-2.67, P = 0.0378), respectively. Mechanistically, the rhodanine derivatives inhibited the nuclear localization and transcriptional activity of HIF-2α in chondrocytes and FLS. They did not bind to Zn²⁺ or modulate Zn²⁺ homeostasis in chondrocytes or FLS; instead, they inhibited the nuclear localization and transcriptional activity of the Zn²⁺-dependent transcription factor, MTF1. HIF-2α, ZIP8, and interleukin-1β could upregulate matrix-degrading enzymes in chondrocytes and FLS, and the rhodanine derivatives inhibited these effects.

CONCLUSION

IA administration of rhodanine derivatives significantly reduced OA pathogenesis in various mouse models, demonstrating that these derivatives have disease-modifying therapeutic potential against OA pathogenesis.

Universal Early Coarsening of Quenched Bose Gases

We investigate the early coarsening dynamics of an atomic Bose gas quenched into a superfluid phase. Using a two-step quench protocol, we independently control the two cooling rates during and after passing through the critical region, respectively, and measure the number of quantum vortices spontaneously created in the system. The latter cooling rate regulates the temperature during the condensate growth, consequently controlling the early coarsening dynamics in the defect formation. We find that the defect number shows a scaling behavior with the latter cooling rate regardless of the initial cooling rate, indicating universal coarsening dynamics in the early stage of condensate growth. Our results demonstrate that early coarsening not only reduces the defect density, but also affects its scaling with the quench rate, which is beyond the Kibble-Zurek mechanism.

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).

Defect Saturation in a Rapidly Quenched Bose Gas

We investigate the saturation of defect density in an atomic Bose gas rapidly cooled into a superfluid phase. The number of quantum vortices, which are spontaneously created in the quenched gas, exhibits a Poissonian distribution not only for a slow quench in the Kibble-Zurek (KZ) scaling regime but also for a fast quench, in which case the mean vortex number is saturated. This shows that the saturation is not caused by destructive vortex collisions, but by the early-time coarsening in an emerging condensate, which is further supported by the observation that the condensate growth lags the quenching in the saturation regime. Our results demonstrate that the defect saturation is an effect beyond the KZ mechanism, opening a path for studying critical phase transition dynamics using the defect number distribution.

Critical Energy Dissipation in a Binary Superfluid Gas by a Moving Magnetic Obstacle

We study the critical energy dissipation in an atomic superfluid gas with two symmetric spin components by an oscillating magnetic obstacle. Above a certain critical oscillation frequency, spin-wave excitations are generated by the magnetic obstacle, demonstrating the spin superfluid behavior of the system. When the obstacle is strong enough to cause density perturbations via local saturation of spin polarization, half-quantum vortices (HQVs) are created for higher oscillation frequencies, which reveals the characteristic evolution of critical dissipative dynamics from spin-wave emission to HQV shedding. Critical HQV shedding is further investigated using a pulsed linear motion of the obstacle, and we identify two critical velocities to create HQVs with different core magnetization.

Masking of High-Translucency Zirconia for Various Cores

CLINICAL RELEVANCE

Various core materials with different shades affect the final color of high-translucency monolithic zirconia restorations. The blue core shows the greatest color difference in final zirconia restorations followed by metal, A3 dentin-shade resin core, and white core.

SUMMARY

The purpose of this study was to evaluate the masking ability of high-translucency monolithic zirconia for various core materials. A computer-aided design-computer-aided manufacturing system was used to design a zirconia disc with a diameter of 10 mm and a thickness of 1.0 mm. Four groups of cores (n=15 each) were fabricated with blue-colored dual-cure resin, white-colored dual-cure resin, A3 dentin-shade composite resin, and titanium block with 10-mm diameter and 5-mm thickness.Dual-cure, self-adhesive resin cement discs with a thickness of 25.0 ± 0.02 μm were fabricated. The color was measured using a handheld spectrophotometer. Color measurements of all specimens were performed on a white background. To assess the masking ability of zirconia, the difference between the values measured with zirconia on a white background and the values measured with zirconia on each of the four types of core material as a background with the cement specimens interposed (zirconia + cement + core) was determined. To enhance the optical connection between the specimens, distilled water was applied between each layer during each measurement.The results showed that the value of ΔE was highest for the blue core followed by metal, A3 dentin-shade resin core, and white-resin core. No significant differences were observed between the metal core and the A3 dentin-shade resin core or between the A3 dentin-shade resin core and the white core. The blue core had the significantly highest ΔE value based on Tukey's honest significant difference test.Different core materials affect the final color of high-translucency monolithic zirconia restorations. Thus, our study showed that the final color of high-translucency monolithic zirconia restorations could be affected by the type of core material used.

Antimicrobial activity of ClO2 gas against Salmonella Enteritidis on almonds

Nuts, including almonds, are occasionally contaminated with Salmonella spp. In this study, we used chlorine dioxide (ClO₂) gas to inactivate S. enterica subsp. Enterica serovar Enteritidis on almonds. Almonds inoculated with a single strain of S. Enteritidis (8.95 log cfu/mL) were exposed to ClO₂ gas generated from 1.0 or 1.5 mL ClO₂ solution in a sealed container at 50 or 60 °C (43% relative humidity) for up to 10 h. The concentration of ClO₂ gas peaked at 354-510 and 750-786 ppm within 0.5 h upon deposition of 1.0 and 1.5 mL of aqueous ClO₂, respectively, and gradually decreased thereafter. Population of S. Enteritidis on almonds treated at 50 °C decreased to 1.70-2.32 log cfu/sample within 1 h of exposure to ClO₂ gas and decreased to below the detection limit (1.7 log cfu/sample) at all ClO₂ concentrations after 8 h. At 60 °C, the microbial population fell below the detection limit within 1 h, regardless of the volume of ClO₂ solution supplied. Microbial survival on almonds treated with ClO₂ gas and stored at 12 or 25 °C was observed for up to 8 weeks and the organism was not recovered from the almonds treated for 10 h and stored at 12 °C for 2-8 weeks. The lightness (L value) and redness (a value) of almonds treated for 10 h were not changed by ClO₂ gas treatment, but yellowness (b value) increased. Results showed that Salmonella on almonds was successfully inactivated by ClO₂ gas treatment and the microbial survival did not occur during storage.

Parental concerns during COVID-19-related school closures: Children’s behaviors and media usage

Introduction

While coronavirus disease 2019 (COVID-19) spreads across the globe, many countries have closed schools to ensure physical distancing to slow transmission and ease the burden on health systems. Concerns regarding Coronavirus Disease 2019 (COVID-19) school closures often increase stress levels in parents.

Objectives

This study examined whether higher levels of parental concerns were associated with children’s problematic behaviors and other factors during COVID-19-related primary school closures.

Methods

Participants were 217 parents who responded to a web-based questionnaire covering parental concerns, subjective stress, and depression; children’s sleep patterns, behavioral problems, and changes in activity level after COVID-19; previously received mental health services; and media usage during the online-only class period from community center in Suwon city.

Results

The number of parental concerns was associated with children’s behavioral problem index (BPI) score (Pearson correlation 0.211, p < 0.01), sleep problems (0.183, p < 0.01), increased smartphone usage (0.166, p < 0.05), increased TV usage (0.187, p < 0.01), parents’ subjective stress levels (0.168, p < 0.05), and parental depression (0.200, p < 0.01). In families with children who previously received mental health services, the children reportedly suffered from more sleep and behavioral problems but not increased media usage, and parents noted more stress and depression. Parental concerns are related to family factors such as change of caregiver, no available caregiver, decreased household income, and recent adverse life events.

Conclusions

Ongoing monitoring of mental health at risky group and multiple support systems should be considered for parents having difficulty in caring their children.

Lacticaseibacillus absianus sp. nov., isolated from the cecum of a mini-pig

A rod-shaped, facultative anaerobic, Gram-stain-positive bacteria, isolated from the cecum of a mini-pig, was designated as strain YH-lac23^T. Analysis of 16S rRNA gene sequences revealed that the strain was closely related to Lacticaseibacillus daqingensis JCM 33273^T (97.9 %), Lacticaseibacillus porcinae KCTC 21027^T (96.2 %) and Lacticaseibacillus manihotivorans KCTC 21010^T (95.7 %). Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster with L. daqingensis. The average nucleotide identity value for YH-lac23^T and its most closely related strain (L. daqingensis) is 80.7 %. The main fatty acids are C_18 : 1ω9c and C_16 : 0. The cell wall contains the peptidoglycan of meso-diaminopimelic acid. The G+C content of the genomic DNA is 59.8 mol%. In view of the chemotaxonomic, phenotypic and phylogenetic properties, YH-lac23^T (=KCTC 25006=JCM 33998) represents a novel taxon. The name Lacticaseibacillus absianus sp. nov. is proposed.

Description of Paenibacillus dokdonensis sp. nov., a new bacterium isolated from soil

Two strains isolated from soil samples were designated as YH-JAE5^T and YH-JAE2. The isolates were facultative anaerobic, Gram-stain-variable, motile, rod-shaped bacteria. Phylogenetic analysis indicated that the isolates belonged to the genus Paenibacillus, but the 16S rRNA gene sequence similarities were <98 % when compared with other species within the genus. Analysis of rpoB gene revealed the isolates formed a sub-cluster with P. chibensis. The only menaquinone identified was MK-7. The two isolates contained meso-diaminopimelic acid within their cell wall peptidoglycan. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phospholipid, aminophospholipids, and lipids. The major fatty acids were C_15 : 0 anteiso and C_15 : 0 iso. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between isolate YH-JAE5^T and the most closely related reference strain (Paenibacillus chibensis KCTC 3758^T) were 81.7, 84.8 and 23.4 %, respectively. The G+C content of the genomic DNA was 47.4 mol%. Thus, the polyphasic data revealed that YH-JAE2 (=KCTC 43239=JCM 34435) and YH-JAE5^T (=KCTC 43059=JCM 33533) represent a new species. The name Paenibacillus dokdonensis sp. nov. is proposed.

Clostridium vitabionis sp. nov., isolated from the large intestine of a mini-pig

An obligately anaerobic, Gram-stain-negative, spore-forming, short rod-shaped bacterium, designated strain YH- T4B42^T, was isolated from the large intestine of a mini-pig. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Clostridium and is most closely related to Clostridium aminophilum KCTC 5424^T, Clostridium symbiosum KCTC 15329^T and Clostridium butyricum KCTC 1871^T, with 95.5, 92.4 and 83.0 % sequence similarity, respectively. The average nucleotide identity values for strain YH-T4B42^T and the closest related strains were lower than 72 %. The G+C content of the isolate was 55.8 mol%. The cell-wall peptidoglycan was A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C_16 : 0, C_18 : 1 cis 9, C_14 : 0 and C_18 : 0. The major end products of glucose fermentation were lactate, formate and acetate, with a minor amount of butyrate. Based on its phenotypic, phylogenetic and chemotaxonomic properties, a novel species, Clostridium vitabionis sp. nov., is proposed for strain YH-T4B42^T (=KCTC 25105^T=NBRC 114767^T).

Lentilactobacillus kribbianus sp. nov., isolated from the small intestine of a mini pig

A Gram-stain-positive, facultative anaerobic, rod-shaped bacteria isolated from the small intestine of a mini pig was designated as strain YH-lac9^T. 16S rRNA gene sequence analysis revealed that the strain belongs to the genus Lentilactobacillus and is closely related to Lentilactobacillus senioris JCM 17472^T, Lentilactobacillus rapi JCM 15042^T and Lentilactobacillus diolivorans JCM 13927^T, with 97.6, 96.2 and 95.7 % sequence similarity, respectively. Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster with L. senioris, supporting the results of 16S rRNA gene sequences analysis. The average nucleotide identity value for YH-lac9^T and the most closely related strain is 74.1 %. The main fatty acids are C_18 : 1ω9c, summed feature 7, C_16 : 0 and summed feature 8. The G+C content of the genomic DNA is 37.8 mol%. In view of its chemotaxonomic, phenotypic and phylogenetic properties, YH-lac9^T (=KCTC 25005=JCM 33997) represents a novel taxon. The name Lentilactobacillus kribbianus sp. nov. is proposed.

Paenibacillus oralis sp. nov., Isolated from Human Subgingival Dental Plaque of Gingivitis Lesion

A Gram-stain-negative, facultative anaerobic, spore-forming, motile, and rod-shaped bacterium, strain ChDC PVNT-B20^T, was isolated from the human subgingival dental plaque of a gingivitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) showed that the strain belonged to the genus Paenibacillus. BLAST analysis of 16S rDNA sequence of the strain displayed high identity to those of Paenibacillus faecis DSM 23593^T (97.7% similarity) and Paenibacillus macerans ATCC 8244^T (97.6% similarity). Draft genome of strain ChDC PVNT-B20^T was composed of 8,112,407 bp. The DNA G+C content of the strain was 51.3 mol%. Average nucleotide identity values between strain ChDC PVNT-B20^T and P. faecis DSM 23593^T or P. macerans ATCC 8244^T were 75.71% and 91.5%, respectively. Genome-to-genome distance values between strain ChDC PVNT-B20^T and P. faecis DSM 23593^T or P. macerans ATCC 8244^T were 21.6% (19.3-24.0%) and 44.9% (42.3-47.4%), respectively. Major cellular fatty acids of strain ChDC PVNT-B20^T were anteiso-C_15:0 (43.4%), C_16:0 (16.6%), iso-C_16:0 (14.4%), and anteiso-C_17:0 (12.4%). The sole respiratory quinone of the strain was menaqinone-7. Major polar lipids of the strain were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and one unidentified glycolipid (GL). Minor polar lipids were one unidentified aminolipid (AL), one unidentified phospholipid (PL), and three unidentified lipids (L1-L3). Based on these results, strain ChDC PVNT-B20^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus oralis sp. nov. is proposed. Type strain is ChDC PVNT-B20^T (= KCOM 3021^T = JCM 33462 ^T).

Streptococcus koreensis sp. nov., Isolated from Human Subgingival Dental Plaque of Periodontitis Lesion

A novel facultative anaerobic, Gram-stain-positive coccus, strain JS71^T, was isolated from the human subgingival dental plaque of a periodontitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) revealed that the strain belonged to the genus Streptococcus. The 16S rDNA sequence had high similarity with Streptococcus rubneri DSM 26920^T (98.6%), Streptococcus parasanguinis ATCC 15912^T (98.5%), and Streptococcus australis CCUG 45919^T (98.3%). The genome of strain JS71^T was 2,009,592 bp in length. The DNA G+C content of the strain was 42.1 mol%. Average nucleotide identity values between strain JS71^T and S. rubneri DSM 26920^T, S. parasanguinis ATCC 15912^T, and S. australis CCUG 45919^T were 88.9%, 80.8%, and 92.4%, respectively. Genome-to-genome distance values between strain JS71^TS. rubneri DSM 26920^T, S. parasanguinis ATCC 15912^T, and S. australis CCUG 45919^T were 36.5% (34-39%), 26.3% (23.9-28.7%), and 48.0% (45.4-50.6%), respectively. The major fatty acids of the strain were C_16:0 (39.7%), C_{18:1 ω6c}/C_{18:1 ω7c} (15.5%), and C_18:0 (10.4%). Based on these results, strain JS71^T (= KCOM 2890^T = JCM 33454^T) should be a novel species of the genus Streptococcus, for which the name Streptococcus koreensis sp. nov. is proposed.

Lautropia dentalis sp. nov., Isolated from Human Dental Plaque of a Gingivitis Lesion

A novel Gram-stain-negative, motile, and facultative anaerobic coccus, strain ChDC F240^T was isolated from human subgingival dental plaque of a gingivitis lesion. The phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) sequence showed that the strain belonged to the genus Lautropia. 16S rDNA of strain ChDC F240^T had the highest similarity to that of Lautropia mirabilis ATCC 51599^T (98.8%). Major cellular fatty acids of strain ChDC F240^T were C_16:0 (43.9%) and C_16:1ω6C/C_16:1ω7C (38.1%). Draft genome of the strain was 3,834,139 bp in length and the G+C content was 65.0 mol%. Average nucleotide identity and genome-to-genome distance values between strain ChDC F240^T and L. mirabilis ATCC 51599 ^T were 81.99% and 28.50% (26.1-30.9%), respectively. These results reveal that strain ChDC F240^T is a novel species within the genus Lautropia, for which the name Lautropia dentalis sp. nov. is proposed; type strain is ChDC F240^T (= KCOM 2505^T = JCM 33297^T).

Lachnoanaerobaculum gingivalis sp. nov., Isolated from Human Subgingival Dental Plaque of a Gingivitis Lesion

A novel Gram-stain-positive, obligately anaerobic, spore-forming rod, designated strain ChDC B114^T, was isolated from a human dental plaque of a gingivitis lesion. The strain was characterized by polyphasic taxonomic analysis to identify it at the species level. The 16S ribosomal RNA gene (16S rDNA) sequence analysis revealed that the strain belongs to the genus Lachnoanaerobaculum. The percent similarity of the 16S rDNA of the strain was closest to the homologous gene sequence of Lachnoanaerobaculum orale N1^T (98.5%) and Lachnoanaerobaculum saburreum CCUG 28089^T (97.6%). The major fatty acids of strain ChDC B114^T were C_16:0 (30.7%), C_14:0 (17.7%), iso-C_19:0 (14.9%), and C_17:0 2OH (12.0%). The draft genome of strain ChDC B114^T was 3,097,953 bp in length. The G+C content of the strain was 35.9 mol %. Average nucleotide identity values between strain ChDC B114^T and L. orale N1^T and L. saburreum CCUG 28089^T were 83.2% and 82.0%, respectively. Genome-to-genome distance values between strain ChDC B114^T and L. orale N1^T and L. saburreum CCUG 28089^T were 26.8% (24.5-29.3%) and 26.30% (24.0-28.8%), respectively. Based on these results, strain ChDC B114^T (= KCOM 2030^T = JCM 33452^T) should be classified as a novel species of genus Lachnoanaerobaculum, for which the name Lachnoanaerobaculum gingivalis sp. nov. is proposed.

Streptococcus periodonticum sp. nov., Isolated from Human Subgingival Dental Plaque of Periodontitis Lesion

A novel facultative anaerobic and Gram-stain-positive coccus, designated strain ChDC F135^T, was isolated from human subgingival dental plaque of periodontitis lesion and was characterized by polyphasic taxonomic analysis. The 16S rRNA gene (16S rDNA) sequence of strain ChDC F135^T was closest to that of Streptococcus sinensis HKU4^T (98.2%), followed by Streptococcus intermedia SK54^T (97.0%), Streptococcus constellatus NCTC11325^T (96.0%), and Streptococcus anginosus NCTC 10713^T (95.7%). In contrast, phylogenetic analysis based on the superoxide dismutase gene (sodA) and the RNA polymerase beta-subunit gene (rpoB) showed that the nucleotide sequence similarities of strain ChDC F135^T were highly similar to the corresponding genes of S. anginosus NCTC 10713^T (99.2% and 97.6%, respectively), S. constellatus NCTC11325^T (87.8% and 91.4%, respectively), and S. intermedia SK54^T (85.8% and 91.2%, respectively) rather than those of S. sinensis HKU4^T (80.5% and 82.6%). The complete genome of strain ChDC F135^T consisted of 1,901,251 bp and the G+C content was 38.9 mol %. Average nucleotide identity value between strain ChDC F135^T and S. sinensis HKU4^T or S. anginosus NCTC 10713^T were 75.7% and 95.6%, respectively. The C_14:0 composition of the cellular fatty acids of strain ChDC F135^T (32.8%) was different from that of S. intermedia (6-8%), S. constellatus (6-13%), and S. anginosus (13-20%). Based on the results of phylogenetic and phenotypic analysis, strain ChDC F135^T (= KCOM 2412^T = JCM 33300^T) was classified as a type strain of a novel species of the genus Streptococcus, for which we proposed the name Streptococcus periodonticum sp. nov.

Fusobacterium pseudoperiodonticum sp. nov., Isolated from the Human Oral Cavity

In the present study, three strains (ChDC F213^T, ChDC F251, and ChDC F267) were classified as novel species of genus Fusobacterium based on average nucleotide identity (ANI) and genome-to-genome distance (GGD) analysis and chemotaxonomic characterization. 16S rDNA sequences of strains ChDC F213^T, ChDC F251, and ChDC F267 were highly similar to that of F. periodonticum ATCC 33693^T (99.6, 99.4, and 99.4%, respectively). ANI and GGD values of the three isolates with F. periodonticum ATCC 33693^T ranged from 92.5 to 92.6% and 47.7 to 48.2%, respectively. Considering that threshold of ANI and GGD values for bacterial species discrimination are 95-96% and 70%, respectively, these results indicate that the three isolates represent a novel Fusobacterium species. DNA G + C contents of the three isolates were 28.0 mol% each. Cellular fatty acid analysis of these strains revealed that C_14:0, C_16:0, and C_16:1 ω6c/C_16:1 ω7c were major fatty acids. Therefore, these three strains are novel species belonging to genus Fusobacterium. Strain ChDC F213^T (= KCOM 1259^T = KCTC 5677^T = JCM 33009^T) is the type strain of a novel species of genus Fusobacterium, for which a name of Fusobacterium pseudoperiodonticum sp. nov. is proposed.

Observation of Wall-Vortex Composite Defects in a Spinor Bose-Einstein Condensate

We report the observation of spin domain walls bounded by half-quantum vortices (HQVs) in a spin-1 Bose-Einstein condensate with antiferromagnetic interactions. A spinor condensate is initially prepared in the easy-plane polar phase, and then, suddenly quenched into the easy-axis polar phase. Domain walls are created via the spontaneous Z_{2} symmetry breaking in the phase transition and the walls dynamically split into composite defects due to snake instability. The end points of the defects are identified as HQVs for the polar order parameter and the mass supercurrent in their proximity is demonstrated using Bragg scattering. In a strong quench regime, we observe that singly charged quantum vortices are formed with the relaxation of free wall-vortex composite defects. Our results demonstrate a nucleation mechanism for composite defects via phase transition dynamics.

Band Gap Closing in a Synthetic Hall Tube of Neutral Fermions

We report the experimental realization of a synthetic three-leg Hall tube with ultracold fermionic atoms in a one-dimensional optical lattice. The legs of the synthetic tube are composed of three hyperfine spin states of the atoms, and the cyclic interleg links are generated by two-photon Raman transitions between the spin states, resulting in a uniform gauge flux ϕ penetrating each side plaquette of the tube. Using quench dynamics, we investigate the band structure of the Hall tube system for a commensurate flux ϕ=2π/3. Momentum-resolved analysis of the quench dynamics reveals a critical point of band gap closing as one of the interleg coupling strengths is varied, which is consistent with a topological phase transition predicted for the Hall tube system.

Evaluation of the Microshear Bond Strength of MDP-containing and Non-MDP-containing Self-adhesive Resin Cement on Zirconia Restoration

OBJECTIVES

The purpose of this study was to measure the microshear bond strength (μSBS) of four different self-adhesive resin cements with/without 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primer to zirconium ceramics and to evaluate the effect of zirconia primers on these self-adhesive resin cements (SARCs).

METHODS AND MATERIALS

Zirconia blocks (20 × 20 × 8 mm³) were prepared and divided into eight groups (n=20). They were sandblasted (50 μm Al₂O₃) and treated as follows: no primer or primer (Z-Primer Plus). Four self-adhesive resin cements (MDP-containing: Permacem 2.0 [PC], Clearfil SA luting [CS]; non-MDP-containing: Rely-X U200 [RU], Maxcem Elite [ME]) were bonded to the zirconia surface. After thermocycling, a μSBS test was performed. The failure mode was analyzed using light microscopy. Statistical analysis of μSBS was performed using one-way analysis of variance and two-sample t-test with post hoc Tukey test. The loss rate was evaluated using the Fisher's exact test and χ² test with post hoc Tukey test (p<0.05).

RESULTS

Within the no primer groups, the PC and CS groups showed higher bond strength than the RU and ME groups. Comparing the μSBS of the no primer and primer groups in the same SARCs, the RU/P group was higher than the RU group, and the ME/P group was higher than the ME group. No significant difference was observed between the PC and PC/P groups and between the CS and CS/P groups.

CONCLUSIONS

Non-MDP-containing SARC showed the increased bonding value with MDP-containing primer to zirconia ceramics. The bond strength of MDP-containing SARCs was not affected significantly by the use of zirconia primer.

Critical Vortex Shedding in a Strongly Interacting Fermionic Superfluid

We study the critical vortex shedding in a strongly interacting fermionic superfluid of ^{6}Li across the BEC-BCS crossover. By moving an optical obstacle in the sample and directly imaging the vortices after the time of flight, the critical velocity u_{vor} for vortex shedding is measured as a function of the obstacle travel distance L. The observed u_{vor} increases with decreasing L, where the rate of increase is the highest in the unitary regime. In the deep Bose-Einstein condensation regime, an empirical dissipation model well captures the dependence of u_{vor} on L, characterized by a constant value of η=-[d(1/u_{vor})/d(1/L)]. However, as the system is tuned across the resonance, a step increase of η develops about a characteristic distance L_{c} as L is increased, where L_{c} is comparable to the obstacle size. This bimodal behavior is strengthened as the system is tuned towards the BCS regime. We attribute this evolution of u_{vor} to the emergence of the underlying fermionic degree of freedom in the vortex-shedding dynamics of a Fermi condensate.

Blautia argi sp. nov., a new anaerobic bacterium isolated from dog faeces

Two isolates of a Gram-positive, non-motile, coccoid or oval-shaped anaerobic bacterium, designated strains N6H1-15^T and YH1_16, were isolated from faecal samples obtained from a mature dog. Analysis of 16S rRNA gene sequences indicated that the isolates belonged to the Blautia coccoidesrRNA gene group (cluster XIVa) and were closely related to Blautia hansenii KCTC 5951^T, Blautia stercoris KCTC 5981^T, Blautia producta producta KCTC 3695^T and B. coccoides DSM 15327^T, with 96.7, 94.4, 94.2 and 93.9 % sequence similarity, respectively. The two isolates contained m-diaminopimelic acid within their peptidoglycans. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol, and the major fatty acids were C16 : 0 (18.5 %), C16 : 0 (18.0 %) and C18 : 1cis 9 (16.2 %). The predominant metabolic end products of glucose fermentation were acetic and lactic acids, and the G+C content was 44.2 mol%. Thus, the polyphasic data suggest that the two new isolates represent a new species, proposed as Blautia argi sp. nov. The type strain is N6H1-15^T (=KCTC 15426=JCM 31394).

Realization of a Cross-Linked Chiral Ladder with Neutral Fermions in a 1D Optical Lattice by Orbital-Momentum Coupling

We report the experimental realization of a cross-linked chiral ladder with ultracold fermionic atoms in a 1D optical lattice. In the ladder, the legs are formed by the orbital states of the optical lattice and the complex interleg links are generated by the orbital-changing Raman transitions that are driven by a moving lattice potential superimposed onto the optical lattice. The effective magnetic flux per ladder plaquette is tuned by the spatial periodicity of the moving lattice, and the chiral currents are observed from the asymmetric momentum distributions of the orbitals. The effect of the complex cross-links is demonstrated in quench dynamics by measuring the momentum dependence of the interorbital coupling strength. We discuss the topological phase transition of the chiral ladder system for the variations of the complex cross-links.

The roughening kinetics of hydrogenated graphene

The roughness is a common property of all growing surfaces – however, the way the roughness of a growing surface changes with time and space is uniquely related to the underlying growth process, i.e. to how the atoms stick to the surface during the first stage of nucleation. This concept allows getting insights on the nucleation process of a growing surface by measuring two scaling exponents, α and β, known as roughness and growth exponents, respectively. In this work, we studied hydrogenation of graphene using the roughening kinetics. The coverage of graphene will depend on how the H ions stick on the surface, giving rise to a unique roughness evolution in time and space. We measured a roughness exponent of ~0.5 (derived from a Fourier index of ~3), and a growth exponent of ~0.3. The values of the growth and roughness exponents are close to those reported for clustered carbon, suggesting a roughening mechanism by clustering, in good agreement with the theory. We also compared our coverage data with a different model, used to describe the dynamics of graphene coverage, during chemical vapour deposition. Our data are in agreement with a nucleation-dominated growth, further confirming that hydrogenation is happening by clustering.