CRISPR/Cas12a Collateral Cleavage-Driven Transcription Amplification for Direct Nucleic Acid Detection.

The clustered regularly interspaced short palindromic repeat/Cas (CRISPR/Cas) system is a powerful tool for nucleic acid detection owing to specific recognition as well as cis- and trans-cleavage capabilities. However, the sensitivity of CRISPR/Cas-based diagnostic approaches is determined by nucleic acid preamplification, which has several limitations. Here, we present a method for direct nucleic acid detection without preamplification, by combining the CRISPR/Cas12a system with signal enhancement based on light-up RNA aptamer transcription. We first designed two DNA templates to transcribe the light-up RNA aptamer and kleptamer (Kb) RNA: the first DNA template encodes a Broccoli RNA aptamer for fluorescence signal generation, and the Kb DNA template comprises a dsDNA T7 promoter sequence and an ssDNA sequence that encodes an antisense strand for the Broccoli RNA aptamer. Hepatitis B virus (HBV) target recognition activates a CRISPR/Cas12a complex, leading to the catalytic cleavage of the ssDNA sequence. Transcription of the added Broccoli DNA template can then produce several Broccoli RNA aptamer transcripts for fluorescence enhancement. The proposed strategy exhibited excellent sensitivity and specificity with 22.4 fM detection limit, good accuracy, and stability for determining the target HBV dsDNA in human serum samples. Overall, this newly designed signal enhancement strategy can be employed as a universal sensing platform for ultrasensitive nucleic acid detection.

Prevalence estimation of Tropheryma whipplei in duodenal biopsy tissues of Koreans.

Whipple's disease caused by Tropheryma whipplei is difficult to diagnose because of a broad spectrum of manifestations and non-specific clinical signs. In the current global era, the incidence of duodenal infection/inflammation caused by T. whipplei in Korea may has been underestimated. Here we estimated the prevalence of T. whipplei in duodenal biopsy tissues of Koreans using real-time PCRs (RT-PCRs). A total of 252 duodenal biopsy tissues were collected from Korean patients who underwent esophagogastroduodenoscopy and duodenal biopsy. DNA extracted from the duodenal biopsy tissues was analyzed using three RT-PCRs targeting T. whipplei-specific regions of the 16S-23S rRNA intergenic spacer, hsp65, and Dig15 in parallel. In the samples positive in RT-PCRs, direct sequencing was performed for each RT-PCR target. The prevalence of T. whipplei was estimated based on the RT-PCR and sequencing results. Among the analyzed samples, T. whipplei was not detected. The prevalence of T. whipplei in duodenal biopsy tissues of Koreans was estimated to be less than 0.4%. This is the first study to attempt to detect T. whipplei in duodenal biopsy tissues of Koreans and estimate its prevalence. Our findings infer that while T. whipplei carriers exist in Korea, the incidence of duodenal infection/inflammation caused by T. whipplei is extremely rare.

Development of a multidisciplinary medication management program in nursing homes: protocol for a randomized controlled trial : Multidisciplinary medication management in nursing homes.

BACKGROUND: Polypharmacy and the use of potentially inappropriate medications are common among nursing home residents and are associated with negative outcomes. Although deprescribing has been proposed as a way to curtail these problems, the best way to implement multidisciplinary comprehensive medication review and deprescribing and its real impact in specific high-risk populations, such as nursing home residents, is still unclear. This multicenter randomized controlled clinical trial aims to assess the effects of a multidisciplinary mediation management program on medication use and health problems. METHODS: A total of 1,672 residents aged ≥ 65 years from 22 nursing homes in South Korea who meet the targeted criteria, such as the use of ≥ 10 medications, are eligible to participate. The experimental group will receive a comprehensive medication review, deprescription, and multidisciplinary case conference with the help of platform. Outcomes will be measured at baseline, at the end of the intervention, as well as at 3, 6, 9, and 12 months after the end of the intervention. The primary endpoints will be the rate of adverse drug events, number of potentially inappropriate medications/potentially inappropriate medication users/two or more central nervous system drug/ central nervous system drug users, delirium, emergency department visits, hospitalization, and falls. The secondary endpoint will be the number of medications taken and polypharmacy users. DISCUSSION: Our trial design is unique in that it aims to introduce a structured operationalized clinical program focused on reducing polypharmacy and potentially inappropriate medications in a nursing home setting with large samples. TRIAL REGISTRATION: Ethical approval was granted by the public institutional review board of the Ministry of Health and Welfare (2022-1092-009). The study is also registered with the Clinical Research Information Service (Identifier: KCT0008157, Development and evaluation of a multidisciplinary medication management program in long-term care facility residents Status: Approved First Submitted Date: 2023/01/18 Registered Date: 2023/02/03 Last Updated Date: 2023/01/18 (nih.go.kr) https://cris.nih.go.kr/ ), which includes all items from the World Health Organization Trial Registration Dataset.

Collinsella urealyticum sp. nov., a urease-positive bacterial strain isolated from swine faeces.

A novel actinobacterial strain, designated AGMB00827T, was isolated from swine faeces. Strain AGMB00827T was obligately anaerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped bacterium. Comparative analyses based on the 16S rRNA gene and whole genome sequence revealed that strain AGMB00827T was affiliated to the genus Collinsella, and was most closely related to Collinsella vaginalis Marseille-P2666T (= KCTC 25056T). Biochemical analysis showed strain AGMB00827T was negative for catalase and oxidase. Interestingly, strain AGMB00827T possessed urease activity, which was determined by traditional methods (API test and Christensen's urea medium), unlike related strains. Furthermore, the major cellular fatty acids (> 10%) of the isolate were C18:1 ω9c, C16:0, C16:0 DMA and C18:2 ω9,12c DMA. Based on the whole genome sequence analysis, the DNA G + C content of strain AGMB00827T was 52.3%, and the genome size and numbers of rRNA and tRNA genes were 1,945,251 bp, 3 and 46, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain AGMB00827T and C. vaginalis KCTC 25056 T were 71.0 and 23.2%, respectively. Additionally, the genome analysis revealed that strain AGMB00827T possesses urease gene cluster including ureABC and ureDEFG while the related strains do not have those genes, which is consistent with the urease activity. On the basis of polyphasic taxonomic approach, strain AGMB00827T represents a novel species within the genus Collinsella, for which the name Collinsella urealyticum sp. nov. is proposed. The type strain is AGMB00827T (= KCTC 25287T = GDMCC 1.2724T).

Leisingera thetidis sp. nov., isolated from coastal water.

A Gram-strain-negative, strictly aerobic, rod-shaped, catalase-positive, oxidase-positive and pinkish beige colony-forming bacterial strain designated as BMJM1T was isolated from a marine sample collected from coastal water near Tongyeong, Republic of Korea. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that BMJM1T represents a member of the genus Leisingera as it is closely related to Leisingera daeponensis KCTC 12794T (98.27%), Leisingera caerulea DSM 24564T (97.98%), Leisingera aquaemixtae KCTC 32538T (97.91%), Leisingera methylohalidivorans DSM 14336T (97.26%) and Leisingera aquimarina DSM 24565T (97.25%). Optimal growth occurred at 25-30°C, pH 7.0 and with 2% NaCl. Digital DNA-DNA hybridisation (dDDH) and average nucleotide identity (ANI) values between strain BMJM1T and the closely related species of the genus Leisingera were below 40 and 90%, respectively, which are far below the thresholds to delineate a novel species. The predominant fatty acids (>10%) are summed feature 8 (C18:1ω7c and/or C18:1ω6c) (68.4%) and C14:1iso E (11.6%). The major polar lipids were phosphatidylethanolamine and phospholipid. The major isoprenoid quinone was ubiquinone-10. The DNA G+C content was 64.0%. On the basis of the results of the polyphasic taxonomic characterisation, BMJM1T represents a novel species of the genus Leisingera, for which the name is Leisingera thetidis sp. nov. is proposed, with that type strain BMJM1T (= KCTC 92110T = GDMCC 1.2992T).

Evaluation of ichroma™ COVID-19 interferon gamma release assay for detection of vaccine-induced immunity in healthcare workers.

OBJECTIVES: We compared the performance of a new interferon gamma release assay (IGRA) format assay, the ichroma™ COVID-19 IGRA (IGRA-SARS), with that of the widely used QuantiFERON SARS-CoV-2 ELISA kit (QFN-SARS) in vaccinated healthcare workers (HCWs). Additionally, we analyzed the long-term changes in IGRA results after the final vaccine dose. METHODS: A total of 383 specimens from 281 HCWs were enrolled in this study, and the results of SARS-IGRA and QFN-SARS assays were compared. In addition, we performed the receive operator curve analysis to estimate the optimal cut-off value for IGRA-SARS. RESULTS: For all specimens, IGRA-SARS and QFN-SARS showed 75.7% and 64.2% of the positive results, respectively. The absolute agreement between IGRA-SARS and QFN-SARS was 80.0%, and the Fleiss' κ value was 0.525, indicating moderate agreement. ROC curve analysis of the IGRA-SARS results showed a cut-off value of >0.254 IU/mL, which was consistent with the manufacturer's specifications. The positive rates of both IGRA assays decreased significantly after a postvaccination period of 6 months. CONCLUSIONS: IGRA-SARS showed acceptable performance in the detection of vaccine-induced immunity against COVID-19; however, harmonization of IGRA assays has not yet been achieved. Additionally, the significant decline of positive rates of IGRA after the last vaccination would support the necessity of booster vaccination after a postvaccination period of 6 months.

Prognostic value of resting heart rate in predicting undiagnosed diabetes in adults: Korean National Health and Nutrition Examination Survey 2008-2018.

BACKGROUND AND AIM: Although resting heart rate (RHR) is associated with prevalence and incidence of diabetes, whether it is associated with undiagnosed diabetes is still unclear. We aimed to investigate whether the RHR is associated with the prevalence of undiagnosed diabetes in a large Korean national dataset. METHODS AND RESULTS: The Korean National Health and Nutrition Examination Survey data from 2008 to 2018 were used. After screening, 51,637 participants were included in this study. The odds ratios and 95% confidence intervals (CIs) for undiagnosed diabetes were calculated using multivariable-adjusted logistic regression analyses. Analyses showed that participants with a RHR of ≥90 bpm showed a 4.00- (95% CI: 2.77-5.77) and 3.21-times (95% CI: 2.01-5.14) higher prevalence of undiagnosed diabetes for men and women, respectively, than those with a RHR of <60 bpm. The linear dose-response analyses showed that each 10-bpm increment in RHR was associated with a 1.39- (95% CI: 1.32-1.48) and 1.28-times (95% CI: 1.19-1.37) higher prevalence of undiagnosed diabetes for men and women, respectively. In the stratified analyses, the positive association between RHR and the prevalence of undiagnosed diabetes was tended to be stronger among those who were younger (age: <40 years) and lean (BMI: <23 kg/m2). CONCLUSIONS: Elevated RHR was significantly associated with a higher prevalence of undiagnosed diabetes in Korean men and women, independent of demographic, lifestyle, and medical factors. Accordingly, the value of RHR as a clinical indicator and health marker, especially in reducing the prevalence of undiagnosed diabetes, is suggestible.

Emticicia fluvialis sp. nov., a potential hormone-degrading bacterium isolated from Nakdong River, Republic of Korea.

A novel species of the genus Emticicia, designated BHSR1T, was isolated from a water sample that was collected from the Nakdong River, Republic of Korea, and its taxonomic affiliation was studied using a polyphasic approach. This bacterium was Gram-stain-negative, non-motile, aerobic, curved, rod-shaped, and oxidase- and catalase-negative. The bacterium grew optimally at 37 °C, pH 7.5 and 0% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain BHSR1T should be affiliated with the genus Emticicia, with a high similarity to Emticicia fontis KCTC 52248T (98.10%). Phylogenomic analysis also suggested that the strain represents a novel species in the genus Emticicia. The genomic G + C content was 41.9%. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization between strain BHSR1T and its closely related relatives in the genus Emticicia were in ranges of 71.1-75.8%, 69.4-77.5% and 18.6-19.9%, respectively. The gene cluster within BHSR1T contained genes encoding enzymes that could be involved in hormone degradation. The major cellular fatty acids (> 10%) were summed feature 3 (comprising C16:1ω6c and/or C16:1ω7c) and iso-C15:0. With regards to the polar lipid profile, phosphatidylethanolamine (PE), two unidentified aminolipids and three unidentified lipids were identified as the major compounds. The major respiratory quinone was menaquinone (MK)-7. Based on its phylogenetic, phenotypic, chemotaxonomic, and genomic features, strain BHSR1T should be considered a novel species in the genus Emticicia of the family Spirosomaceae, for which the name Emticicia fluvialis sp. nov. is proposed. The type strain was considered BHSR1T (= KCTC 92622T = GDMCC 1.3740T).

Caproiciproducens faecalis sp. nov., Isolated from Cow Faeces.

The bacterial strain AGMB10547T was isolated from cow faeces deposited by the National Institute of Animal Science in Cheonan, Republic of Korea. The strain AGMB10547T possessed the phenotypic, biochemical and chemotaxonomic characteristics of the bacteria of the family Oscillospiraceae. The isolate was obligately anaerobic, non-motile, Gram-positive and rod-shaped bacteria. The growth of strain AGMB10547T occurred within 35-40 °C (optimum at 37 °C), at pH 6-7 (optimum of 7) and in the presence of 0.5-2.0% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, strain AGMB10547T belonged to the genus Caproiciproducens and was most closely related to Caproiciproducens galactitolivorans BS-1T (96.9%). The DNA G+C content was 49.0 mol%. The major cellular fatty acids (> 10%) of the isolate were C14:0, C14:0 DMA, C16:1 ω9c and C16:0. The average nucleotide identity (ANI) and digital DNA-DNA Hybridization (dDDH) values between strain AGMB10547T and C. galactitolivorans BS-1T were 75.5% and 19.2%. Based on the phenotypic, genotypic, biochemical and chemotaxonomic analyses, strain AGMB10547T represents a novel species of the genus Caproiciproducens, for which the name Caproiciproducens faecalis sp. nov. is proposed. The type strain AGMB10547T (=KCTC 25200T=NBRC 115006T=GDMCC 1.2575T).

Parabacteroides faecalis sp. nov. Isolated from Swine Faeces.

A Gram-negative, obligate anaerobic, non-motile, non-spore-forming, rod-shaped bacterial strain designated AGMB00274T was isolated from swine faeces. An 16S rRNA gene analysis indicated that strain AGMB00274T belonged to the genus Parabacteroides, with the highest similarity to Parabacteroides johnsonii (P. johnsonii) DSM 18315T (sequence similarity of 94.9%). The genome size of strain AGMB00274T was 4,308,683 bp, with a DNA G+C content of 42.5 mol%. The biochemical analysis of strain AGMB00274T showed that it was positive for gelatin hydrolysis and α-fucosidase, but negative for the acid production from D-glucose, D-mannitol, D-maltose, salicin, glycerol, D-cellobiose, D-mannose, D-melezitose, D-sorbitol, D-trehalose, and negative for α-arabinosidase, glutamic acid decarboxylase, and pyroglutamic acid arylamidase. The dominant cellular fatty acids (> 10%) of the isolate were anteiso-C15: 0 (23.2%), iso-C15: 0 (16.6%), C18: 1 ω9c (16.4%), summed feature 11 (iso-C17: 0 3-OH and/or C18: 2 DMA) (12.5%), and C16: 0 (11.3%). The major respiratory quinones of strain AGMB00274T were MK-9 (55.4%) and MK-10 (44.6%). The major polar lipid was phosphatidylethanolamine. Based on phylogenetic, genetic, physiological, and chemotaxonomic analyses, as a novel species of the genus Parabacteroides, strain AGMB00274T was proposed with the name Parabacteroides faecalis sp. nov. The type strain used was AGMB00274T (= KCTC 25286T = GDMCC 1.2742T).

Risk factors associated with the incidence and prevalence of hypertension in Ghana: an integrated review (2016-2021).

This study synthesized the risk factors associated with hypertension among adolescents and adults in Ghana. A systematic search in four databases between 2016 and 2021 retrieved 119 Ghanaian studies, and through screening, 16 were selected. Thematic analysis was used to synthesize extracted data. Prevalence of hypertension ranged from 13.0% to 28.4% and prehypertension 22.0% to 51.4%. The non-modifiable hypertension risk factors were age, marital status, gender, and residence. The modifiable risk factors were consuming additional table salt, salted meat, alcohol, canned meats, smoking, and psychological factors, including stress and anxiety. Also, higher education and socio-economic status, employment, access to medical insurance, overweight, and higher BMI were risk factors. Targeted, sustained, systematic, and effective intervention programs should target high-risk people.

Single-Molecule Sensing of an Anticancer Therapeutic Protein-Protein Interaction Using the Chemically Modified OmpG Nanopore.

Nanopore sensors are a highly attractive platform for single-molecule sensing for sequencing, disease diagnostics, and drug screening. Outer membrane protein G (OmpG) nanopores have advantages for single-molecule sensing owing to their rigid monomeric structure, which comprises seven flexible loops, providing distinct gating patterns upon analyte binding. Blocking of the protein-protein interaction between B-cell lymphoma-extra-large (Bcl-xL) and the BH3 domain of Bcl-2 homologous antagonist/killer (Bak-BH3) has been reported as a promising strategy for anticancer therapy. Here, we characterized the interaction between Bcl-xL and Bak-BH3 as well as its inhibition by a small-molecule inhibitor using click chemistry-based Bak-BH3 peptide-conjugated OmpG nanopores. The binding of Bcl-xL to Bak-BH3 generated characteristic gating signals involving significant changes in the amplitudes of noise and gating parameters such as gating frequency, open probability, and durations of open and closed states. Notably, specific inhibition of Bcl-xL by the small-molecule antagonist, ABT-737, led to the recovery of the noise and gating parameters. Collectively, these results revealed that the chemically modified OmpG nanopore can serve as a valuable sensor platform for ultrasensitive, rapid, and single-molecule-based drug screening against protein-protein interactions, which are therapeutic targets for various diseases.

Performance Evaluation of Bruker Biotyper, ASTA MicroIDSys, and VITEK-MS and Three Extraction Methods for Filamentous Fungal Identification in Clinical Laboratories.

Filamentous fungi are a major cause of life-threatening infections in immunocompromised patients; thus, rapid and accurate identification is critical. Filamentous fungal identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been demonstrated with high sensitivity and reproducibility; however, its wider application has been limited in clinical laboratories because of practical challenges such as database availability or lack of standardization. In this study, we compared the performance of the Bruker Biotyper, ASTA MicroIDSys, and Vitek MS for 84 clinical filamentous fungal isolates. Moreover, the sensitivity of three independent sample preparation methods (direct, on plate, in tube) was compared. Bruker Biotyper identified 71.43% (60/84) of isolates correctly (species, genus, or complex/group level). ASTA MicroIDSys and Vitek MS showed accuracy rates of 70.24% (59/84) and 55.95% (47/84), respectively. We found that any difference in sensitivity may be attributed to the database of the systems. In addition, the "in tube" method showed the highest sensitivity among the three methods; however, there was no statistical difference among them. For the broader application of MALDI-TOF MS for filamentous fungal identification, further studies from multiple perspectives are required.

Olsenella intestinalis sp. nov., isolated from cow feces.

A Gram-stain-negative, anaerobic, non-motile, rod-shaped bacterium, designated as BGYT1T, was isolated from the feces of a cow in Andong, Republic of Korea. It was studied using a polyphasic method to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BGYT1T formed a lineage within the genus Olsenella and was most closely related to O. umbonate KCTC 15140T (98.2%). The complete genome sequence of strain BGYT1T was 2,476,083 bp long with a G + C content of 66.9 mol% and contained 1835 genes and 8 contigs. The N50 value was 604,117 bp. There were 50 tRNAs, 6 rRNAs (5S, 16S, 23S), 1778 CDSs and 2 BGCs and 1 tmRNA. The values for ANI (76.8%), AAI (67.3%), and dDDH (22.2%) compared to the closest related species were all below the threshold for bacterial species delineation. In addition, genes encoding the cell wall degrading enzymes such as chitinases, ß-1,3 glucanases, and proteases were also detected. The strain was able to grow at pH 6.0-8.0 (optimum, pH 7.0), in the presence of 0.5-1.5% NaCl (optimum, 0.5%, w/v) and at the temperature range of 35-40 °C (optimum, 35 °C). The predominant fatty acids were C16:0 DMA (20.2%), C16:0 (20.2%), C18:0 (10.5%) and C18:1 cis 9 (17.0%). The polar lipids consisted of an unidentified phospholipid, four unidentified glycolipids and three unidentified lipids. Based on its phenotypic analyses, phylogenetic and physiological characteristics, strain BGYT1T represented a novel species within the genus Olsenella, for which the name Olsenella intestinalis sp. nov. is proposed. The type strain is BGYT1T (= KCTC 25379T = GDMCC 1.3011T).

Pseudophaeobacter flagellatus sp. nov., isolated from coastal water.

A Gram-stain-negative, aerobic, motile, rod-shaped novel bacterial strain, designated as MA21411-1T, was isolated from the Korean coast. The colonies were white-yellow-coloured, smooth, convex and entire, spherical and 1.0-1.8 mm in diameter. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain MA21411-1T is closely related to species of the genus Pseudophaeobacter. The 16S rRNA gene sequence similarities between strain MA21411-1T and Pseudophaeobacter arcticus DSM 23566T, Phaeobacter porticola DSM 103148T and Pseudophaeobacter leonis DSM 25627T were 98.31, 97.80 and 97.28 %, respectively. Strain MA21411-1T has a draft genome size of 4 294 042 bp, annotated with 4125 protein-coding genes, and 53 tRNA, three rRNA and one tmRNA genes. The genomic DNA G+C content was 59.2 mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain MA21411-1T and other related species were below the cut-off levels of 95, 70 and 95.5 %, respectively. The growth temperature range for growth was 15-28 °C (optimum, 25 °C), pH range was 6.0-9.0 (optimum, pH 6.0), and salt tolerance range was 0.5-4 % (optimum 0.5 %). Ubiquinone-10 was the sole quinone present in MA21411-1T and all three closely related strains. The major cellular fatty acid (>10 %) of the strain was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and four unidentified polar lipids. Based on the phylogenetic tree, as well as phenotypic, chemotaxonomic and genomic features, strain MA21411-1T represents a novel species of the genus Pseudophaeobacter, for which the name Pseudophaeobacter flagellatus sp. nov. is proposed. The type strain is MA21411-1T (=KCTC 92095T=GDMCC 1.2988T).

Arsenicicoccus cauae sp. nov., isolated from the blood of a pediatric gastroenteritis patient.

A Gram-stain-positive coccus was isolated from the blood of a paediatric patient suffering from gastroenteritis. The taxonomic position of this catalase-positive, non-motile, non-spore-forming facultative anaerobe designated as strain MKL-02T was investigated using a polyphasic approach. Colonies grown on tryptic soy agar with 10 % sheep blood were circular, creamy yellow, and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that this strain was most closely related to Arsenicicoccus bolidensis CCUG 47306T within the cluster of the genus Arsenicicoccus. Average nucleotide identity and digital DNA-DNA hybridization values between strain MKL-02T and A. bolidensis DSM 15745T, A. dermatophillus DSM 25571T and A. piscis DSM 22760T were 89.5 and 37.0 %, 79.6 and 22.4 %, and 75.9 and 21.0 %, respectively. The genomic size of strain MKL-02T was 3 423 857 bp with a 72.7 mol% G+C content. Growth was observed at 10-45 °C (optimum, 37-40 °C) and pH 6.0-10.0 (optimum, pH 7.0), in the presence of 0-10 % (w/v) NaCl (optimum, 0.5 %). Cells of strain MKL-02T were non-motile cocci and 0.50-0.60 µm long, as determined by transmission electron microscopy. The strain was catalase-positive and oxidase-negative. The major fatty acid type (>10 % of total) was C15 : 0. The polar lipid profile consisted of two unidentified phospholipids, three unidentified lipids and an unidentified aminophospholipid. The strain contained MK-8 (H4) as the predominant menaquinone. Based on phylogenetic and phenotypic considerations, it is proposed that strain MKL-02T be classified as a new species, named Arsenicicoccus cauae sp. nov. The type strain is MKL-02T (=NCCP 16967T=JCM 34624T).

Associations among the TREM-1 Pathway, Tau Hyperphosphorylation, Prolactin Expression, and Metformin in Diabetes Mice.

INTRODUCTION: Diabetes mellitus (DM) is a risk factor for Alzheimer's disease (AD). Increasing evidence indicates that the triggering receptor expressed on myeloid cells (TREM)-1 amplifies chronic inflammation, as well as the roles of prolactin (PRL) and metformin (MET) in tau hyperphosphorylation. However, the associations among TREM-1, tau hyperphosphorylation, PRL expression, and MET in DM remain unclear. METHODS: Streptozotocin was used to induce experimental DM in C57BL/6N mice. MET was orally administered at a dose of 400 mg/kg body weight for 6 weeks prior to hippocampal collection in DM mice. Various parameters pertaining to the TREM-1 pathway, tau hyperphosphorylation, PRL, and related factors were analyzed. RESULTS: Quantitative polymerase chain reaction and Western blot analysis demonstrated that the expression levels of TREM-1, DAP12, casp1, interleukin-1ß, Cox2, inducible nitric oxide synthase, pituitary transcriptional factor-1 (Pit-1), and PRL were significantly increased in the hippocampus of DM mice; the expression levels of these pro-inflammatory mediators, PRL receptor (PRLR) short or long (PRLR-S and PRLR-L), and PRL regulatory element-binding (Preb) protein in DM mice treated with MET (DM + MET) were significantly decreased compared with those in control (CON) mice. The levels of p-Tau and glycogen synthase kinase-3 in the DM group were significantly higher than those in the CON group and significantly lower than those in the DM + MET group. CONCLUSION: We confirmed the therapeutic potential of MET for both DM and neurodegeneration. Our findings shed new light on the effects of DM on the pathophysiology of AD via the TREM-1 pathway and PRL expression. Thus, an improved understanding of the TREM-1 pathway in hyperglycemic conditions, as well as PRL, Preb, Pit-1, PRLR-L, and PRLR-S gene expression in the liver, brain, and other sites, may help unravel the pathogenesis of insulin resistance and neurodegeneration.

Prevalence and detection of Tropheryma whipplei in the stools of Korean patients with diarrhea using real-time PCRs.

BACKGROUND: The prevalence of Tropheryma whipplei varies depending on age, region, and underlying disease. We estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea using real-time PCR (RT-PCR) and compared three RT-PCR targets, rpoB, hsp65, and Dig15. METHODS: A total of 1404 nucleic acid samples extracted from the stools of Korean patients with diarrhea were tested using an initial RT-PCR targeting T. whipplei-specific regions of 16S-23S rRNA intergenic spacer. Subsequently, the samples positive for the initial RT-PCR were tested using the follow-up RT-PCRs targeting rpoB, hsp65, and Dig15 and analyzed by sequencing to confirm the presence of T. whipplei. We estimated the prevalence of T. whipplei and compared them according to gender and age. We also compared the performance of three targets in the follow-up RT-PCRs. RESULTS: T. whipplei was detected in 1.4% of all samples (20 of 1404), and there were no differences according to gender and age. In pediatric samples (≤ 19 years), T. whipplei was detected higher in children aged 6-19 than in those aged 1-5 (2.7% vs. 0.7%, P = 0.01). Sensitivities of the rpoB, hsp65, and Dig15 RT-PCR were 50.0%, 85.0%, and 95.0%, respectively; specificities were 100.0%, 100.0%, and 84.6%, respectively. CONCLUSIONS: This is the first study that estimated the prevalence of T. whipplei in the stools of Korean patients with diarrhea. This study demonstrated the presence of T. whipplei in stools of Koreans, even though the bacterium was detected low. The RT-PCRs targeting hsp65 and Dig15 showed reliable performance, and a multiplex PCR including these targets is expected to be useful for T. whipplei detection.

Seasonal trends of mercury bioaccumulation and assessment of toxic effects in Asian clams and microbial community from field study of estuarine sediment.

This study investigated seasonal trends in bioaccumulation potential and toxic effects of mercury (Hg) in Asian clams (Corbicula fluminea) and microbial community. For this, a clam-exposure experiment was performed during summer, fall, and winter seasons in four different sites (HS1: control/clean site; HS2, HS3, and HS4: contaminated sites) of Hyeongsan River estuary, South Korea. Total mercury (THg) and methylmercury (MeHg) in whole sediments were highest at HS4 site during fall, sustained similar levels during winter, but decreased during summer. Unlike whole sediment, pore water reported higher levels in summer, and gradually declined during fall and winter. Asian clams from HS4 site collected during summer presented highest bioaccumulations of THg (521.52 µg/kg, dry weight) and MeHg (161.04 µg/kg, dry weight), which also correlated with the higher levels of Hg present in pore water in the same season. Moreover, biota-sediment-pore water accumulation factor (BSpAF) were comparatively greater in clams collected from HS2∼HS4 compared to HS1 sites, suggesting that porewater was a better indicator of accumulation of Hg. Upregulation of biomarker genes responsible for detoxifying process (gsts1), scavenging oxidative stress (cat), and protein reparation (hsp70 and hsp90) were observed in clams collected from HS2∼HS4. The overexpression of these biomarkers implied that Asian clams can be considered as promising warning tools for Hg-contamination. Both bacterial and metabolic diversities were negatively affected by higher levels of THg and MeHg. Phylum Proteobacteria was enriched in HS2∼HS4 compared to HS1. In contrast, phylum Bacteroidetes showed a reverse trend. The metabolic profile was highest in HS1 and lowest in HS4, revealing higher stress of Hg in HS4 site. Overall, the outcomes of this field study broaden the information on seasonal trends of bioaccumulation of Hg and its toxic effects. These findings may be helpful in Hg monitoring and management programs in other river systems.

SERS-based dual-mode DNA aptasensors for rapid classification of SARS-CoV-2 and influenza A/H1N1 infection.

We developed a dual-mode surface-enhanced Raman scattering (SERS)-based aptasensor that can accurately diagnose and distinguish severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/H1N1 at the same time. Herein, DNA aptamers that selectively bind to SARS-CoV-2 and influenza A/H1N1 were immobilized together on Au nanopopcorn substrate. Raman reporters (Cy3 and RRX), attached to the terminal of DNA aptamers, could generate strong SERS signals in the nanogap of the Au nanopopcorn substrate. Additionally, the internal standard Raman reporter (4-MBA) was immobilized on the Au nanopopcorn substrate along with aptamer DNAs to reduce errors caused by changes in the measurement environment. When SARS-CoV-2 or influenza A virus approaches the Au nanopopcorn substrate, the corresponding DNA aptamer selectively detaches from the substrate due to the significant binding affinity between the corresponding DNA aptamer and the virus. As a result, the related SERS intensity decreases with increasing target virus concentration. Thus, it is possible to determine whether a suspected patient is infected with SARS-CoV-2 or influenza A using this SERS-based DNA aptasensor. Furthermore, this sensor enables a quantitative evaluation of the target virus concentration with high sensitivity without being affected by cross-reactivity. Therefore, this SERS-based diagnostic platform is considered a conceptually new diagnostic tool that rapidly discriminates against these two respiratory diseases to prevent their spread.