Hip Fracture Management during the COVID-19 Pandemic in South Korea

Background

The purpose of this study was to introduce a screening system for coronavirus disease 2019 (COVID-19), to evaluate the overall orthopedic management in hip fracture patients during the COVID-19 pandemic in South Korea, and to compare the surgical results in hip fracture patients during the COVID-19 pandemic with those of the previous year.

Methods

Hip fracture patients who visited emergency rooms were screened at the screening clinics before admission. The medical management was carried out with the medical staff wearing surgical masks, meticulous hand hygiene observed, and a minimum distance of 2 m between patients maintained. The demographics, operative parameters, and surgical results of patients treated during the pandemic were compared with those from the previous year.

Results

From January 2020 to July 21, 2020, 119 patients with hip fractures (33 men and 86 women) were admitted to our institution for surgical treatment. Five patients showed symptoms of pneumonia, but no patient was positive for COVID-19. The mortality rate during the study period was 4.2%, and none of the patients died due to COVID-19. The interval between admission and surgery and the length of hospital stay were significantly shorter (p = 0.008, p = 0.002) and the proportion of spinal anesthesia was greater in hip fracture patients during the COVID-19 pandemic compared to those from the previous year (p = 0.011).

Conclusions

The COVID-19 screening system for hip fracture patients has proven to be effective in preventing intrahospital spread of the disease. Hip fracture surgery performed during the COVID-19 pandemic has shown comparable results without any COVID-19 infection and COVID-19-related mortality.

Estimation of Measurement Uncertainty of Factor Assays Using the Monte Carlo Simulation

OBJECTIVES

We aimed to quantify the measurement uncertainty (MU) for factor activities using the Monte Carlo simulation (MCS), which is a computational algorithm that simulates statistical sampling to obtain numerical results through complex mathematical calculations.

METHODS

The uncertainties of factor V (FV), factor VIII (FVIII), and factor X (FX) were simulated with two coagulation testing systems: ACL TOP 750 CTS (Instrumentation Laboratory) and STA Compact (Diagnostica Stago).

RESULTS

When the factor activities were 74% (FV), 68% (FVIII), and 89% (FX), the MUs were 3.5% (FV), 9.3% (VIII), and 2.8% (FX) for ACL TOP and 8.5% (FV), 18.2% (FVII), and 6.5% (FX) for STA Compact. MCS MUs were compared with MUs obtained from running actual samples (not simulated) using a method called the top-down approach. The MCS MU results were interchangeable with MUs from the top-down approach, except for FVIII from STA Compact.

CONCLUSIONS

The MCS procedure is well suited for the quantification of MUs for factor assays over the entire measurement range.

Anaerosporobacter faecicola sp. nov. isolated from faeces of Korean cow

A novel bacterial isolate designated as strain AGMB01083^T was isolated from Korean cow faeces deposited in the National Institute of Animal Science (Wanju, Republic of Korea). The bacterium is obligate anaerobic, Gram-strain-positive, and motile. Cells are straight or curved rod-shaped, flagella and spores are observed. Growth occurs between 20-40 °C (temperature optimum of 35 °C), at pH 7-9 (pH optimum of 7), and in the presence of 0.5-1.0 % (w/v) NaCl. Based on the 16S rRNA gene sequence analysis, the strain belongs to the genus Anaerosporobacter and is most closely related to A. mobilis HY-37-4^T (=KCTC5027^T, similarity, 95.7 %). The DNA G+C content is 36.2 mol%, determined by the whole-genome sequence. The average nucleotide identity value between strain AGMB01083^T and strain A. mobilis HY-37-4^T is 75.5 %, below the interspecies identity threshold value. The major cellular fatty acids (>10 %) of strain AGMB01083^T are C_16 : 0, C_16 : 0 dimethyl acetal (DMA), and C_16 : 0 3-OH. Based on the phylogenetic, phenotypic, biochemical, chemotaxonomic, and genomic characterization, strain AGMB01083^T is proposed to be a novel species, named Anaerosporobacter faecicola, in the genus Anaerosporobacter. The type strain is AGMB01083^T (=KCTC 15857^T=NBRC 114517^T).

Phocaeicola faecicola sp. nov., isolated from porcine faeces

An obligately anaerobic, non-motile, Gram-negative and rod-shaped strain (AGMB03916^T) was isolated from faeces of a 2-week-old piglet raised at the National Institute of Animal Science in Wanju, Republic of Korea. Growth of strain AGMB03916^T occurred at 30-45 °C (optimum, 37 °C), at pH 6-9 (optimum, pH 8) and in the presence of 0.5-1.0 % (w/v) NaCl. Based on the results of 16S rRNA gene sequence analyses, strain AGMB03916^T was closely related to two validly published species of the genus Phocaeicola, Phocaeicola plebeius and Phocaeicola coprocola. The 16S rRNA gene sequence similarity of strain AGMB03916^T compared to P. plebeius M12^T (=KCTC 5793^T) and P. coprocola M16^T (=KCTC 5443^T) were 96.3 and 95.0 %, respectively. The genomic DNA G+C content of strain AGMB03916^T was 46.4 mol%. The average nucleotide identity values between strain AGMB03916^T and the reference strains were 74.9-78.5 %. Cells were able to utilize d-glucose, lactose, sucrose, maltose, salicin, aesculin hydrolysis, cellobiose and raffinose. The major end product of metabolism was acetate. The major cellular fatty acids (>10 %) of the isolate were iso-C_15 : 0, anteiso-C_15 : 0, C_16 : 0, C_16 : 0 3-OH and summed feature 11 (iso-C_17 : 0 3-OH and/or C_18 : 2 DMA). On the basis of the genotypic, biochemical, chemotaxonomic, phenotypic and phylogenetic data, strain AGMB03916^T represents a novel species of the genus Phocaeicola, for which the name Phocaeicola faecicola sp. nov. is proposed. The type strain is AGMB03916^T (=KCTC 25014^T=GDMCC 1.2574^T).

A Novel Species of the Genus Arsenicicoccus Isolated From Human Blood Using Whole-Genome Sequencing

Whole-genome sequencing (WGS) is an easily accessible and valuable tool in clinical microbiology, which can be used for identifying novel and rare species. We isolated gram-positive cocci from the blood of a pediatric patient, which could not be phenotypically identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) (BioMérieux, Marcy-l'Étoile, France). We could not identify the isolate to the species level using 16S ribosomal RNA (rRNA) sequencing. WGS was performed using the Illumina MiSeq platform (Illumina, San Diego, CA, USA); however, the subsequent genomic sequence database search using the TrueBac ID-Genome system (ChunLab, Inc., Seoul, Korea) did not yield any hits with an average nucleotide identity value >95.0%, which is the cut-off for species-level identification. Phylogenetic analysis suggested that the isolate belonged to a new Arsenicicoccus species, forming a subcluster with Arsenicicoccus bolidensis. Our data demonstrate that WGS allows a more accurate annotation of microbial genomes than other clinical microbiology tools, such as MALDI-TOF MS and 16S rRNA sequencing. This is the first report of the isolation of a novel Arsenicicoccus species from a clinical sample.

Ten-Year Prevalence Trends of Phenotypically Identified Community-Associated Methicillin-Resistant Staphylococcus aureus Strains in Clinical Specimens

Background

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains were first detected in hospitals in Korea between the late 2000s and early 2010s. However, there is limited information regarding the prevalence of CA-MRSA strains among hospital isolates and their phenotypic changes over the last decade. We investigated the prevalence trend of CA-MRSA strains isolated from different clinical specimens and their phenotypic changes between September 2009 and September 2019.

Methods

CA-MRSA strains were phenotypically identified by confirming their resistance to penicillin (PCN) and oxacillin (OXA) and evaluating their susceptibility to trimethoprim-sulfamethoxazole, rifampin, fusidic acid, tetracycline, and at least one of the following four antimicrobials: clindamycin (CLI), erythromycin (ERY), ciprofloxacin (CIP), and gentamicin (GEN). A CA-MRSA strain that exhibited resistance to ERY, CLI, CIP, or GEN was classified as having resistance pattern I, II, III, or IV, respectively, regardless of its resistance to other antimicrobial agents.

Results

Of the 8,278 MRSA isolates identified in specimens obtained two days after admission, 1,385 (16.73%) were CA-MRSA strains. The prevalence of CA-MRSA strains increased from 12.2% to 26.6% (3.21% per period, P=0.05). Resistance type analysis revealed an increasing trend in the prevalence of PCN/OXA-resistant (1.84%; P=0.049) and PCN/OXA/ERY/CLI/CIP-resistant (0.98%; P=0.04) CA-MRSA strains and in resistance pattern III strains (2.08%; P=0.004).

Conclusions

The prevalence of CA-MRSA strains in Korea has increased significantly over the last decade, and CA-MRSA strains have gained phenotypic diversity beyond PCN/OXA-resistance, including antimicrobial resistance to non-β-lactams, especially CIP.

Clinical and epidemiologic characteristics of inconclusive results in SARS-CoV-2 RT-PCR assays

Background

Inconclusive results in SARS-CoV-2 molecular assays cause confusion among clinicians and delay appropriate infection prevention and control. In this study, we aimed to characterize the respiratory specimens associated with inconclusive SARS-CoV-2 molecular assay results.

Methods

We re-evaluated inconclusive specimens by 3 additional RT-PCR assays and attempted to detect subgenomic RNA (sgRNA) in these specimens.

Results

Among follow-up tests from confirmed SARS-CoV-2 cases, 36.3% of the inconclusive results were classified as presumptive positive results (45/124). However, none of the specimens from 36 screening cases was classified as a presumptive positive result. Among 160 inconclusive specimens, sgRNAs were detected in 78 samples (48.8%): 58 were confirmed cases (58/124, 46.8%) and 20 were screening cases (20/36, 55.6%).

Conclusions

The results of our study suggest the recommendation of considering inconclusive results as positive results for confirmed SARS-CoV-2 cases. In screening cases, viral remnants could be partially amplified in PCR assays, and these inconclusive results could be related to previous infections. In addition, sgRNAs were detected in about half of the inconclusive specimens; however, the clinical significance of sgRNA is not yet clear.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06534-5.

Polygonum multiflorum Thunb. Hot Water Extract Reverses High-Fat Diet-Induced Lipid Metabolism of White and Brown Adipose Tissues in Obese Mice

The purpose of the present study was to determine whether an anti-obesity effect of a Polygonum multiflorum Thunb. hot water extract (PW) was involved in the lipid metabolism of white adipose tissue (WAT) and brown adipose tissue (BAT) in high-fat diet (HFD)-induced C57BL/6N obese mice. Mice freely received a normal diet (NCD) or an HFD for 12 weeks; HFD-fed mice were orally given PW (100 or 300 mg/kg) or garcinia cambogia (GC, 200 mg/kg) once a day. After 12 weeks, PW (300 mg/kg) or GC significantly alleviated adiposity by reducing body weight, WAT weights, and food efficiency ratio. PW (300 mg/kg) improved hyperinsulinemia and enhanced insulin sensitivity. In addition, PW (300 mg/kg) significantly down-regulated expression of carbohydrate-responsive element-binding protein (ChREBP) and diacylglycerol O-acyltransferase 2 (DGAT2) genes in WAT compared with the untreated HFD group. HFD increased BAT gene levels such as adrenoceptor beta 3 (ADRB3), peroxisome proliferator-activated receptor γ (PPARγ), hormone-sensitive lipase (HSL), cluster of differentiation 36 (CD36), fatty acid-binding protein 4 (FABP4), PPARγ coactivator 1-α (PGC-1α), PPARα, and carnitine palmitoyltransferase 1B (CPT1B) compared with the NCD group; however, PW or GC effectively reversed those levels. These findings suggest that the anti-obesity activity of PW was mediated via suppression of lipogenesis in WAT, leading to the normalization of lipid metabolism in BAT.

Characterization of the novel HLA-B*15:598 allele identified in a Korean individual by sequence-based typing

One nucleotide substitution in codon 169 of B*15:01:01:01 results in a novel allele, HLA-B*15:598.

The putative sensor histidine kinase VadJ coordinates development and sterigmatocystin production in Aspergillus nidulans

The VosA-VelB heterocomplex governs expression of several genes associated with fungal development and secondary metabolism. In this study, we have investigated the functions of one of the VosA-VelB-activated developmental genes vadJ in development and production of the mycotoxin sterigmatocystin in the model fungus Aspergillus nidulans. The vadJ gene is predicted to encode a 957-amino acid length protein containing a highly conserved sensor histidine kinase domain. The deletion of vosA or velB resulted in decreased mRNA levels of vadJ throughout the life cycle, suggesting that VosA and VelB are necessary for proper expression of vadJ. Nullifying vadJ led to highly restricted colony growth, lowered formation of asexual spores, and about two-fold reduction in conidial viability. Conversely, the deletion of vadJ resulted in elevated production of sexual fruiting bodies and sterigmatocystin. These suggest that VadJ is necessary for proper coordination of asexual and sexual development, and sterigmatocystin production. In accordance with this idea, the deletion of vadJ led to elevated mRNA levels of the two key sexual developmental activators esdC and nsdD. In summary, the putative sensor histidine kinase VadJ represses sexual development and sterigmatocystin production, but activates asexual development in A. nidulans.

Peptoniphilus faecalis sp. nov., isolated from swine faeces

An obligately anaerobic, Gram-positive, non-motile, coccus-shaped bacterial strain designated AGMB00490^T was isolated from swine faeces. 16S rRNA gene sequence-based phylogenetic analysis indicated that the isolate belongs to the genus Peptoniphilus and that the most closely related species is Peptoniphilus gorbachii WAL 10418^T (=KCTC 5947^T, 97.22 % 16S rRNA gene sequence similarity). Whole genome sequence analysis determined that the DNA G+C content of strain AGMB00490^T was 31.2 mol% and moreover that the genome size and numbers of tRNA and rRNA genes were 2 129 517 bp, 34 and 10, respectively. Strain AGMB00490^T was negative for oxidase and urease; positive for catalase, indole production, arginine arylamidase, leucine arylamidase, tyrosine arylamidase and histidine arylamidase; and weakly positive for phenylalanine arylamidase and glycine arylamidase. The major cellular fatty acids (>10 %) of the isolate were determined to be C_16 : 0 and C_18 : 1 ω9c. Strain AGMB00490^T produced acetic acid as a major end product of metabolism. Accordingly, phylogenetic, physiologic and chemotaxonomic analyses revealed that strain AGMB00490^T represents a novel species for which the name Peptoniphilus faecalis sp. nov. is proposed. The type strain is AGMB00490^T (=KCTC 15944^T=NBRC 114159^T).

Sensitive Detection of SARS-CoV-2 Using a SERS-Based Aptasensor

We developed a new surface-enhanced Raman scattering (SERS)-based aptasensor platform capable of quantifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lysates with a high sensitivity. In this study, a spike protein deoxyribonucleic acid (DNA) aptamer was used as a receptor, and a self-grown Au nanopopcorn surface was used as a SERS detection substrate for the sensible detection of SARS-CoV-2. A quantitative analysis of the SARS-CoV-2 lysate was performed by monitoring the change in the SERS peak intensity caused by the new binding between the aptamer DNA released from the Au nanopopcorn surface and the spike protein in the SARS-CoV-2 virion. This technique enables detecting SARS-CoV-2 with a limit of detection (LoD) of less than 10 PFU/mL within 15 min. The results of this study demonstrate the possibility of a clinical application that can dramatically improve the detection limit and accuracy of the currently commercialized SARS-CoV-2 immunodiagnostic kit.

Performance evaluation of EuDx™ ufPCR Flu & RSV detection kit for detection of influenza A/B and respiratory syncytial virus

EuDx™ ufPCR Flu & RSV Detection Kit (EUDIPIA, Chungcheongbuk-do, Republic of Korea) is a recently developed molecular assay for simultaneously detecting influenza A/B and respiratory syncytial virus (RSV). We evaluated this assay in a clinical setting and demonstrated its excellent performance for diagnosing influenza A/B and RSV infections.

Performance evaluation of newly developed fluorescence immunoassay-based interferon-gamma release assay for the diagnosis of latent tuberculosis infection in healthcare workers

The ichroma™ IGRA-TB (Boditech Med Inc., Chuncheon, Republic of Korea) is an automated fluorescent immunoassay-based point-of-care interferon-gamma release assay for detecting latent tuberculosis infection. We evaluated this assay with 408 health care workers, and demonstrated its acceptable performances comparing to QuantiFERON-TB Gold-Plus (QFT-Plus; Qiagen, Germantown, MD).

Cupriavidus cauae sp. nov., isolated from blood of an immunocompromised patient

A novel Gram-stain-negative, facultative aerobic and rod-shaped bacterium, designated as MKL-01^T and isolated from the blood of immunocompromised patient, was genotypically and phenotypically characterized. The colonies were found to be creamy yellow and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that strain MKL-01^T was most closely related to Cupriavidus gilardii LMG 5886^T, present within a large cluster in the genus Cupriavidus. The genome sequence of strain MKL-01^T showed the highest average nucleotide identity value of 92.1 % and digital DNA-DNA hybridization value of 44.8 % with the closely related species C. gilardii LMG 5886^T. The genome size of the isolate was 5 750 268 bp, with a G+C content of 67.87 mol%. The strain could grow at 10-45 °C (optimum, 37-40 °C), in the presence of 0-10 % (w/v) NaCl (optimum, 0.5%) and at pH 6.0-10.0 (optimum, pH 7.0). Strain MKL-01^T was positive for catalase and negative for oxidase. The major fatty acids were C_16 : 0, summed feature 3 (C_16 : 1  ω7c/C_16 : 1  ω6c and/or C_16 : 1  ω6c/C_16 : 1  ω7c) and summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c). The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified polar lipid. Moreover, strain MKL-01^T contained ubiquinone Q-8 as the sole respiratory quinone. Based on its molecular, phenotypic and chemotaxonomic properties, strain MKL-01^T represents a novel species of the genus Cupriavidus; the name Cupriavidus cauae sp. nov. is proposed for this strain. The type strain is MKL-01^T.

Single-molecule analysis of interaction between p53TAD and MDM2 using aerolysin nanopores

Protein-protein interactions (PPIs) are regarded as important, but undruggable targets. Intrinsically disordered p53 transactivation domain (p53TAD) mediates PPI with mouse double minute 2 (MDM2), which is an attractive anticancer target for therapeutic intervention. Here, using aerolysin nanopores, we probed the p53TAD peptide/MDM2 interaction and its modulation by small-molecule PPI inhibitors or p53TAD phosphorylation. Although the p53TAD peptide showed short-lived (<100 ms) translocation, the protein complex induced the characteristic extraordinarily long-lived (0.1 s ∼ tens of min) current blockage, indicating that the MDM2 recruitment by p53TAD peptide almost fully occludes the pore. Simultaneously, the protein complex formation substantially reduced the event frequency of short-lived peptide translocation. Notably, the addition of small-molecule PPI inhibitors, Nutlin-3 and AMG232, or Thr18 phosphorylation of p53TAD peptide, were able to diminish the extraordinarily long-lived events and restore the short-lived translocation of the peptide rescued from the complex. Taken together, our results elucidate a novel mechanism of single-molecule sensing for analyzing PPIs and their inhibitors using aerolysin nanopores. This novel methodology may contribute to remarkable improvements in drug discovery targeted against undruggable PPIs.

The impact of environmental variables on the spread of COVID-19 in the Republic of Korea

Corona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.

Negative Air Ions Alleviate Particulate Matter-Induced Inflammation and Oxidative Stress in the Human Keratinocyte Cell Line HaCaT

Background

Recent studies have revealed that particulate matter induces inflammation, oxidative stress, and several skin diseases. Experimental results have also shown that negative air ions are highly effective in removing particulate matter-induced inflammation.

Objective

The present study aimed to investigate whether negative air ions can inhibit inflammatory responses and reduce oxidative stress in HaCaT cells exposed to particulate matters.

Methods

HaCaT cells were treated with particulate matter in the presence or absence of negative air ions and the viability was evaluated by the MTT assay. Reactive oxygen species (ROS) generation was quantified by the dichlorodihydrofluorescein diacetate assay. The expression of genes and proteins was analyzed by real-time polymerase chain reaction and Western blot. Levels of inflammatory cytokines were quantified by enzyme-linked immunosorbent assay.

Results

Negative air ions were observed to downregulate the mRNA and protein levels of particulate matter-induced pro-inflammatory cytokines in HaCaT cells. In addition, negative air ion treatment suppressed particulate matter-induced intracellular ROS generation, p38 mitogen-activated protein kinase activation, and activator protein 1 (c-Fos and c-Jun) activation.

Conclusion

Our findings indicate that negative air ions exert anti-inflammatory and antioxidant effects in HaCaT cells exposed to particulate matter. Therefore, negative air ions can be used for the prevention and treatment of particulate matter-related inflammatory skin diseases.

Peribacillus faecalis sp. nov., a moderately halophilic bacterium isolated from the faeces of a cow

A Gram-stain-positive, facultatively anaerobic, endospore-forming, rod-shaped strain, AGMB 02131^T, which grew at 20-40 °C (optimum 30 °C), pH 3.0-11.0 (optimum pH 4.0) and in the presence of 0-18 % (w/v) NaCl (optimum 10 %), was isolated from a cow faecal sample and identified as a novel strain using a polyphasic taxonomic approach. The phylogenetic analysis based on 16S rRNA gene sequences along with the whole genome (92 core gene sets) revealed that AGMB 02131^T formed a group within the genus Peribacillus, and showed the highest sequence similarity with Peribacillus endoradicis DSM 28131^T (96.9 %), following by Peribacillus butanolivorans DSM 18926^T (96.6 %). The genome of AGMB 02131^T comprised 70 contigs, the chromosome length was 4 038 965 bp and it had a 38.5 % DNA G+C content. Digital DNA-DNA hybridization revealed that AGMB 02131^T displayed 21.4 % genomic DNA relatedness with the most closely related strain, P. butanolivorans DSM 18926^T. AGMB 02131^T contains all of the conserved signature indels that are specific for members of the genus Peribacillus. The major cellular fatty acids (>10 %) of AGMB 02131^T were C_18 : 1ω9c, C_18:0 and C_16 : 0. The major polar lipids present were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. On the basis of the phenotypic, phylogenetic, genomic and chemotaxonomic features, AGMB 02131^T represents a novel species of the genus Peribacillus, for which the name Peribacillus faecalis sp. nov. is proposed. The type strain is AGMB 02131^T (=KCTC 43221^T=CCTCC AB 2020077^T).

Risk factors for the delayed diagnosis of extrapulmonary TB

BACKGROUND: Extrapulmonary TB (EPTB) is more difficult to diagnose than pulmonary TB. The delayed management of EPTB can lead to complications and increase the socio-economic burden.METHODS: Patients newly diagnosed with EPTB were retrospectively enrolled from 11 general hospitals in South Korea from January 2017 to December 2018. The basic characteristics of patients were described. Univariable and multivariable analyses were performed between early and delayed diagnosis groups to identify risk factors for delayed diagnosis and treatment in EPTB.RESULTS: In total, 594 patients were enrolled. Lymph node TB (28.3%) was the predominant form, followed by abdominal (18.4%) and disseminated TB (14.5%). Concurrent lung involvement was 17.8%. The positivity of diagnostic tests showed no significant difference between the two groups. Acute clinical manifestations in disseminated, pericardial and meningeal TB, and immunosuppression were associated with early diagnosis. Delayed diagnosis was associated with outpatient clinic visits, delayed sample acquisition and diagnostic departments other than infection or pulmonology.CONCLUSION: The delay in diagnosis and treatment of EPTB was not related to differences in microbiological characteristics of Mycobacterium tuberculosis itself; rather, it was due to the indolent clinical manifestations that cause referral to non-TB-specialised departments in the outpatient clinic and delay the suspicion of TB and diagnostic testing.

Tertiary RNA Folding-Targeted Drug Screening Strategy Using a Protein Nanopore

Bacterial riboswitch RNAs are attractive targets for novel antibiotics against antibiotic-resistant superbacteria. Their binding to cognate metabolites is essential for the regulation of bacterial gene expression. Despite the importance of RNAs as therapeutic targets, the development of RNA-targeted, small-molecule drugs is limited by current biophysical methods. Here, we monitored the specific interaction between the adenine-sensing riboswitch aptamer domain (ARS) and adenine at the single-molecule level using α-hemolysin (αHL) nanopores. During adenine-induced tertiary folding, adenine-bound ARS intermediates exhibited characteristic nanopore events, including a two-level ionic current blockade and a ∼ 5.6-fold longer dwell time than that of free RNA. In a proof-of-concept experiment, tertiary RNA folding-targeted drug screening was performed using a protein nanopore, which resulted in the discovery of three new ARS-targeting hit compounds from a natural compound library. Taken together, these results reveal that αHL nanopores are a valuable platform for ultrasensitive, label-free, and single-molecule-based drug screening against therapeutic RNA targets.