Search

IntroductionCoronavirus disease 2019 (COVID-19) alters the gut microbiome. This study aimed to assess the association between the disease severity of COVID-19 and changes in stool microbes through a seven-month follow-up of stool collection.MethodsWe conducted a multicentre, prospective longitudinal study of 58 COVID-19 patients and 116 uninfected controls. Differences in the gut microbiota were analysed using 16S ribosomal RNA sequencing. The first stool samples were collected at an early convalescent phase of COVID-19, and the second sample was collected at least seven months after COVID-19 infection.Results and discussionAt the order level, Eubacteriales and Bifidobacteriales decreased, while Bacteroidales and Burkholderiales increased in the COVID-19 group compared to the controls. Alpha diversity also decreased in COVID-19 patients compared to controls, with imperfect recovery of the gut microbiome after seven months. The compositional change in the gut microbiome between the early and late convalescent phases was largest in the moderate and severe groups. The severity of COVID-19 was the most influential clinical variable for microbiome composition (Sum of Sqs = 0.686, P = 0.006), and its effect persisted even after partialling out other effects such as antibiotic use and age. Thus, our study indicates a possible interaction between respiratory viral infection and the composition of the gut microbiota community, warranting future mechanistic and prospective longitudinal studies. Additionally, we were able to detect microbiome changes in patients who were re-infected with SARS-CoV-2. Notably, the dominant bacteria in the re-infected group were Lachnospiraceae and Faecalimonas umbilicata, compared to the one-time infected group.

Background: As the group at high risk for sepsis is increasing with the aging of the population, physical activity (PA), which has beneficial effects on various diseases, needs to be considered as a personalized prevention strategy for sepsis without direct anti-sepsis drug. Purpose: To examine the association between the amount of PA (based on intensity, duration, and frequency) and the incidence rates of sepsis and mortality after sepsis. Methods: This was a large-scale, retrospective, longitudinal cohort study using data from the Korean National Health Insurance Service and the biennial general health screening program. The amount of PA self-reported at the time of the health screening was categorized as non-PA, mild (

Abstract Background Sepsis remains a growing global health concern with soaring mortality and no direct anti-sepsis drug. Although smoking has distinct deleterious effects on chronic inflammatory illnesses and can impair immune function, a comprehensive analysis of the connection between sepsis and smoking is lacking. Methods This large-scale longitudinal cohort study retrospectively assessed adults aged ≥ 20 years who underwent national health checkups under the Korean National Health Insurance Service between January and December 2009 (N = 4,234,415) and were followed up for 10 years. Sepsis was identified based on the International Classification of Diseases, 10th Revision codes, and smoking status, including accumulated amount, was collected through a self-administered questionnaire. The Cox proportional hazard regression model was used, adjusting for age, sex, household income, body mass index, drinking, exercise, diabetes, hypertension, dyslipidemia, and chronic renal disease. Results After excluding cases with sepsis occurring before follow-up or after ≤ 1 year of follow-up, 3,881,958 participants, including non-smokers (N = 2,342,841), former smokers (N = 539,850), and active smokers (N = 999,267), were included. Compared to non-smokers, all active smokers (adjust hazard ratio: 1.41, 95% confidence interval 1.38–1.44) and former smokers (1.10, 1.07–1.14) with ≥ 20 pack-years exhibited a significantly higher risk of sepsis (p

Background: Carbapenemase-producing Enterobacterales (CPE) are global concerns in infection control, and the number of CPE outbreaks in hospitals is increasing despite the strengthening of contact precautions. This study aimed to confirm the prevalence and transition rate of CPE infection from stool surveillance culture and to identify the acquisition pathway of CPE. Methods: This is a longitudinal review of patients with stool surveillance cultures at a tertiary center in Seoul, South Korea, from July 2018 to June 2020. Pulsed-field gel electrophoresis, multi-locus sequence typing, and whole genome sequencing were performed for carbapenemase-producing Klebsiella pneumoniae and Escherichia coli strains. Results: Among 1620 patients who had undergone stool CPE surveillance cultures, only 7.1% of active surveillance at the Emergency Room (ER) and 4.4% of universal surveillance in the Intensive Care Unit (ICU) were stool CPE positive. The transition rates from stool carriers to clinical CPE infections were 29.4% in the ER and 31.3% in the ICU. However, it was significantly high (55.0%) in the initial stool CPE-negative ICU patients. Among the initial stool CPE-positive patients, hypertension (61% vs. 92.3%, P = 0.004), malignancy (28.8% vs. 53.8%, P = 0.027), and mechanical ventilation (25.4% vs. 53.8%, P = 0.011) were significant risk factors for clinical CPE infection. Molecular typing revealed that sequence type (ST) 307 and ST 395 were dominant in K. pneumoniae, and ST 410 was dominant in E. coli isolates. Conclusions: Active surveillance showed a higher detection rate than universal stool CPE screening, and one-third of positive stool CPE specimens ultimately developed subsquent clinical CPE infection. According to the molecular typing of the identified CPE strains, in-hospital spread prevailed over external inflow, and the transition rate to clinical CPE was particularly high in the ICU. Therefore, in order to control CPE propagation, not only active surveillance to block inflow from outside, but also continuous ICU monitoring within the hospital is necessary.

Background: Recent studies disputed the effectiveness of efforts to comply with contact precautions and isolation (CPI) considering relatively low intra-hospital transmission rate of healthcare facility-associated Clostridioides difficile infection (HCFA-CDI). We evaluated the potential causal effect of CPI on HCFA-CDI occurrence by comparing the incidence rate (IR) for different time periods with and without CPI implementation. Methods: Long-term observational time-series data were separated into three periods (pre-CPI: January 2012–March 2016, CPI: April 2016–April 2021, post-CPI: May 2021–December 2022). CPI was suspended owing to the restriction of isolation rooms during the COVID-19 pandemic. We inferred potential causal outcomes by comparing predicted and observed IRs of HCFA-CDI using interrupted time-series analyses, including the Bayesian structural time-series or autoregressive integrated moving average (ARIMA) model in the R-language or SAS software. Results: The monthly observed IR (44.9/100,000 inpatient-days) during the CPI period was significantly lower than the predicted IR (90.8) (−50.6% relative effect, P = 0.001). However, the observed IR (52.3) during the post-CPI period was significantly higher than the predicted IR (39.1) (33.6%, P = 0.001). The HCFA-CDI IR decreased during CPI (−14.3, P

[This corrects the article DOI: 10.1371/journal.pone.0266610.].

Abstract Extracorporeal membrane oxygenation (ECMO) provides hemodynamic and oxygenation support to critically ill patients. Due to multiple catheter cannulations, patients on ECMO are vulnerable to bloodstream infections (BSIs). We aimed to investigate the incidence, clinical characteristics, risk factors, and microorganisms associated with BSIs during ECMO. This single-center retrospective cohort study was conducted between January 2015 and May 2021. Patients aged 18 years or older with an ECMO duration of > 48 h for cardiogenic or respiratory support were included in the study. Patients who developed bacteremia or candidemia from 12 h after ECMO cannulation to 7 days after de-cannulation were included. The clinical factors between non-BSI and BSI were compared, along with an analysis of the risk factors associated with BSI during ECMO. A total of 480 patients underwent ECMO for cardiogenic shock (n = 267, 55.6%) or respiratory failure (n = 213, 44.4%) during the study period. The incidence was 20.0 episodes per 1000 ECMO-days. Approximately 20.2% (97/480) and 5.4% (26/480) of the patients developed bacteremia and candidemia, respectively. The median numbers of days of BSI development were 8.00 days for bacteremia and 11.0 days for candidemia. The most common pathogens were methicillin-resistant coagulase-negative staphylococci (n = 24), followed by vancomycin-resistant Enterococcus (n = 21). Multivariable logistic analysis demonstrated that hemodialysis (odds ratio [OR] 2.647, p

Helicobacter pylori is the primary causative agent of gastritis, gastric ulcers, duodenal ulcers, gastric cancer, and peripheral B-cell lymphoma. H. pylori eradication often fails due to elevated antibiotic resistance. However, no previous studies have thoroughly examined amoxicillin resistance. Here, the objective was to identify clinical strains of H. pylori with amoxicillin resistance and to analyze single-nucleotide polymorphisms (SNPs) associated with amoxicillin resistance. From March 2015 to June 2019, genotypic and phenotypic amoxicillin resistance was analyzed using an E-test and whole-genome sequencing (WGS). Analysis of 368 clinical strains confirmed amoxicillin resistance in 31 strains (resistance rate of 8.7%). The genomes were extracted from nine resistant (pbp1a, pbp2, nhaC, hofH, hofC, and hefC in all nine isolates. Some of these genes may be related to amoxicillin resistance. A total of six SNPs (A69V, V374L, S414R, T503I, A592D, and R435Q) were identified in PBP2 of H-8, the most resistant strain. We predict that these six SNPs are associated with high amoxicillin resistance. Amoxicillin resistance should be considered in the clinical setting for the treatment failure of H. pylori eradication.

Infections caused by Fusobacterium species are rare; however serious infections with complications or mortality may occur occasionally. We conducted a retrospective study to investigate the clinical features of patients with Fusobacterium infections and the differences between infections caused by the species F. necrophorum, F. nucleatum, and F. varium. Additionally, we attempted to identify risk factors for Fusobacterium-associated mortality. This study included all patients at a large tertiary care teaching hospital in South Korea with Fusobacterium infections from January 2006 to April 2021. Demographic, clinical, laboratory, and outcome data were analyzed. Multiple logistic regression analysis was performed to assess the risk factors for in-hospital mortality associated with F. nucleatum and F. varium infections. We identified 272 patients with Fusobacterium infections during the study period. The number of Fusobacterium cases has increased recently, with F. varium infections markedly increasing since 2016 and causing a significant proportion of infections. Patients with F. varium infections were older and had a higher proportion of nosocomial infections than the other groups. The F. nucleatum and F. varium groups showed higher in-hospital mortality than the F. necrophorum group. Through logistic regression analysis, APACHE II score and serum albumin level were considered risk factors for in-hospital mortality. APACHE II score was positively correlated with age, red cell distribution width, and serum blood urea nitrogen, and negatively correlated with serum albumin level. Infections caused by Fusobacterium species are increasing. F. varium causes a significant proportion of severe infections.

Selection of proper antibiotics for blood culture-negative infective endocarditis (BCNIE) is difficult due to limited data on antibiotic regimens for BCNIE in existing literature. The aim of this study was to compare ampicillin-sulbactam, other β-lactams antibiotics, and vancomycin among patients with BCNIE to determine the proper antibiotic regimens. This retrospective study included adult patients with BCNIE admitted to Severance Hospital from November 2005 to August 2017. Patients were classified into three groups as, treated with ampicillin-sulbactam, other β-lactams, and vancomycin. The primary outcome was 1-year all-cause mortality. A total of 74 cases with BCNIE were enrolled in this study. There were no statistically significant differences in clinical characteristics between the three groups. One-year mortality did not significantly differ between the study groups either. Further, in-hospital mortality, 28-day mortality and overall mortality showed no difference. However, Cox-regression analysis showed nosocomial infective endocarditis as an independent risk factor and a protective effect of surgery on 1-year mortality. This study showed no clear difference in the outcomes of BCNIE as per the antibiotic therapy but suggested the beneficial effect of surgical treatment. With increasing global concern of antimicrobial resistance, it might be reasonable to select ampicillin-sulbactam-based antibiotic therapy while actively considering surgical treatment in BCNIE.

A new species of arbuscular mycorrhizal fungi (Glomeromycota), Acaulospora koreana, was isolated from forest soils in South Korea. This novel fungus was collected from the rhizosphere of Lindera obtusiloba and Styrax obassia in forest and propagated with Sorghum bicolor in pot. Morphological characteristics of spores of A. koreana are rarely distinguished from Acaulospora mellea, which is reported as one of the most abundant mycorrhizal species in Korea. However, molecular evidence of rDNA sequence using improved primers for glomeromycotan fungal identification strongly supported that A. koreana is different from A. mellea but also any other species belonging to the genus Acaulospora. This is the first novel glomeromycatan fungus introduced in South Korea, but it suggests that there is a high possibility for discovering new arbuscular mycorrhizal fungi considering the abundance of plant species and advanced phylogenetic analysis technique.

배경 Patients with cancer are at greater risk of severe COVID-19 and have been prioritized for COVID-19 vaccination including booster doses. We aimed to assess the immunogenicity and safety of COVID-19 vaccination and analyze factors associated with the immunogenicity of the vaccine among actively treat- ed solid cancer patients (CPs) in Korea. 방법 A prospective cohort was established among CPs undergoing anticancer treatment in a tertiary hospital in Korea. Patients in this cohort had no history of previous SARS-CoV-2 infection confirmed by baseline serological testing and received at least one dose of COVID-19 vaccine in accordance with the vaccine strategy. Blood samples were collected before prime vaccination, and beyond 2 weeks for each dose of vaccine administration. Spike (S)- specific IgG antibodies were analyzed on each sample. Adverse events (AEs) within 7 days following each vaccine dose were collected. Data from age-matched healthcare workers (HCWs) recruited into a separate study are included as a comparison cohort. 결과 Between April 2021 to November 2021, we enrolled 134 CPs; 118 were eligible for analysis. The demographics of CPs and HCWs are described in Table 1. CPs were treated with cytotoxic agents (78.8%), immunotherapy (16.9%), target therapy (18.6%), and others (5.9%), that were given either alone or in combinations. The rate of seroconversion after 1st vaccination in CPs was significantly lower than in HCWs (p value=0.001), however, all CPs and HCWs revealed seroconversion after 2nd vaccination (Figure 1). Antibody response was significantly increased following each dose of vaccination in both CPs and HCWs (Figure 2A). The geometric mean titer (GMT) of S-specific IgG antibodies after 2nd vaccination in CPs who received a primary set of adenovirus vector vaccine were significantly lower than that in HCWs, whereas CPs who received a primary set of mRNA vaccines showed comparable GMT with HCWs after 2nd vaccination (Figure 2B). After the 3rd vaccination, there was no statistical difference in GMT of S-specific antibodies between CPs and HCWs regardless of the type of primary vaccine. In age-matched analysis between good responders (defined as those with higher antibody titers after 2nd vaccination than the mean of age-stratified HCW cohort) and poor responders (defined as those with lower titers) among CPs, there was no significant difference in other factors including the type of vaccine, cancer or anticancer treatment except lower leukocyte counts in poor responders treated with cytotoxic agents. The incidence and severity of AEs were similar between CPs and HCWs without any severe vaccine-related AEs. 결론 Patients with solid cancer had delayed antibody response compared to HCWs after the 1st vaccination but all CPs showed seroconversion after 2nd vaccination. Antibody responses similar to that of HCWs were achieved after the 3rd dose of vaccination in actively treated CPs in this study. [ABSTRACT FROM AUTHOR]

Residential treatment centers (RTCs) are successful in isolating and closely monitoring adults confirmed with coronavirus disease 2019 (COVID-19), but there are concerns for children who need care. This study was conducted as a retrospective analysis of the surveillance of guardians who entered an RTC with infected pediatric patients to identify the secondary attack rate of COVID-19 to close contacts in a single RTC and to provide directions for developing guidelines for caregivers who co-isolate with infected children. When caregivers were admitted to this RTC, aside from negative confirmation before discharge, tests were additionally performed one or two times. There were 57 index children and adolescent patients who entered the RTC with their parents as caregivers. The secondary attack rate by pediatric patients to close contacts outside their households was 25% (95% confidence interval, 10.0 to 40.0) (8 out of 32 contacts). The transmissibility of SARS-CoV-2 in children was close to zero at 6 days after the confirmation tests. It is reasonable to test the close contacts of pediatric patients after 7 days of isolation to identify infections among caregivers. [ABSTRACT FROM AUTHOR]

배경: Many researchers have worked to discover biomarkers to aid the early detection of critically-ill infectious diseases and guide antimicrobial therapy. In this study, we analyzed how often the simultaneous test for CRP, PCT, and IL-6 on the same day has a large diversity, which may lead to erroneous clinical judgments about infection, and the characteristics of patients with normal CRP and PCT and high IL-6 levels at admission. 방법: We retrospectively retrieved total 7,149 simultaneous results of CRP, PCT, and IL-6 within 24 hours of admission between January 2015 and August 2021. All data were transformed through the normalization process (between 0 and 1) by the scikit-learn library. The data were plotted in three-dimensional space, and the dimensionality reduction was made into two dimensions for clustering through t-distributed stochastic neighbor embedding algorithms. We pulled out the group with clinically meaningful discrepancies of CRP, PCT, and IL-6 (normal CRP [<10 mg/L] and PCT [<0.5 ng/mL] but high IL-6 [>100 pg/mL], N=102). 결과: Among high IL-6 (4.9%, 349 of 7,149), 38.7% and 17.8% of PCT and CRP were included in the range of ≤ 0.01. With normal CRP values, 9.2% and 13.4% of results had high PCT (≥ 0.5 ng/mL) and IL-6 (≥ 100 pg/mL) values, respectively. Among low PCT values (≤ 0.5 ng/mL) (n=4,785), 19.8% had high IL-6 levels (≥ 100 pg/mL). Infection and bacteremia or fungemia occurred in 36 (35.3%) and 9 (8.8%), respectively with normal CRP and PCT but high IL-6. Patients with infection had significantly higher IL-6 levels (1450 ± 791 vs. 674 ± 149 pg/mL, P=0.007) and frequency of fever (77.8% vs. 51.5%, P=0.011). 결론: Our study revealed that CRP, PCT, and IL-6 in a simultaneous test were considerably different, which may be clinically misinterpreted if only one or two tests were performed. An IL-6 test may also be helpful to differentiate infection, especially in this situation where CRP is normal. [ABSTRACT FROM AUTHOR]

배경 The superinfection of multidrug-resistant bacteria is an important complication in critically ill COVID-19 patients. An outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) occurred in an isolation ward for COVID-19. We performed an outbreak investigation, and successfully controlled the outbreak with the enhanced environmental cleaning and additional gowning and gloving. 방법 This study analyzed all COVID-19 patients with CRAB in any specimen, who admitted to an isolation ward for COVID-19 of a tertiary hospital in South Korea from October to November 2021. 결과 During the outbreak period, a total of 23 patients with COVID-19 and CRAB were identified. Index case was 85-year old female patient who was referred from a long-term care facility. The mean age of cases was 72.9 and 14 (60.9%) patients were male. In most patients (91.3%), CRAB were identified in sputum culture, two were identified in blood culture at initial, and four patients were identified in sputum and blood culture at the same time. Most of the patients were applying high flow nasal cannula (26.1%) or mechanical ventilation (60.9%)(Table1). As shown in figure2, CRAB outbreak occurred mainly in the wards around the index case, and in particular, environmental culture was carried out in the area marked with a rectangle. CRAB was cultured on the floor, air inlet, air outlet, and window frame of the ward except for wards 3305 and 3319. Phenotypic antimicrobial resistance patterns of CRAB isolates from patients and environment were identical, and additional whole genome sequencing analyses are ongoing to find the clonality of isolates. We applied the infection control measures with the en- hanced environmental cleaning using sodium hypochlorite (NaClO) 1000ppm and phenolic compounds more than twice a day, enhanced hand hygiene, and additional gowning and gloving over personal protective equipment (PPE) mandatory for COVID-19 on 29th October. No additional CRAB cases occurred since 2nd November 2021 for two weeks. 결론 Even when PPEs and precautions for COVID-19 are applied to isolation wards for COVID-19, it is helpful for preventing transmission of multidrug-resistant bacteria to apply additional contact precautions and environmental cleaning [ABSTRACT FROM AUTHOR]

배경: Clostridium difficile infection (CDI) is one of the common causes of healthcare-associated infection. Previous research suggested contact precautions with cohort isolation, but recent studies refuted that standard precautions are sufficient in managing hospital-wide transmission. We evaluated the efficacy of the two by comparing two time periods when CDI was managed with contact precautions or only standard precautions. 방법: This retrospective observational study was conducted between April 2016 and July 2022 in Gangnam Severance Hospital. During the intervention period (April 2016 through April 2021), contact precautions, including cohort isolation for CDI, were incorporated, and only standard precautions were applied during the post-intervention period (May 2021 to July 2022). We predicted CDI cases for the post-intervention period and obtained the difference between the predicted and observed number of cases using Bayesian structural time-series (BSTS) and autoregressive integrated moving average (ARIMA) to evaluate the efficacy of different infection precautions. 결과: The average of observed CDI in the intervention and post-intervention period were 9.9 and 9.3 cases per month, respectively. According to the BSTS model, predicted CDI cases in the post-intervention period were 8.3 cases per month. There was no difference in the observed and predicted CDI cases during the post-intervention period (relative effect [95% credible intervals]; 13 [-12 – 37], p=0.145). ARIMA model also confirms that the numbers in the total CDI cases in the two periods were not different both in the univariable (p=0.792) and the multivariable model adjusted by the number of C. difficile toxin tests (estimate [standard error]; -0.57 [3.4], p=0.867). 결론: Contact precautions for CDI control may be less beneficial considering the effort and resources. Infection control measures should be determined according to the clinical situations of each institution. [ABSTRACT FROM AUTHOR]

배경: There exists alteration of diversity in gut microbiota in Coronavirus disease 2019 (COVID-19) comparing with healthy controls. This study aimed to verify the association between diseases severity and stool microbiota change, and identify the recovery of gut dysbiosis through long term follow-up stool collection. 방법: We conducted a prospective longitudinal study with 58 patients with COVID-19 and 116 age, and sex matched (1:2 ratio) non-infected controls. The difference of gut microbiota between two group was analyzed using 16S ribosomal RNA sequencing. First Stool samples were collected at early phase of COVID-19, and second were collected at completely recovery from diseases (six months later). 결과: At the phylum level, Firmicutes decreased and Bacteroidetes increased in COVID-19 compared to control, and these trends tend to recover in late phase. The alpha diversity also decreased in COVID-19 compared to the control, and it recovered after six months. As the severity of COVID-19 increased, the microbiome dissimilarity between control and disease groups increased. There were significant differences in beta diversity between the various severity groups by the PCoA analysis. After adjusting age, gender, body mass index, and antibiotic use, two biomarkers (positively coefficient: Bacteroides clarus, negatively co- efficient: Blautia massiliensis) were associated with COVID-19. Among the study populations, five patients were later re-infected with SARS-CoV-2 Omicron (B.1.1.529) variant, and Faecalimonas umbilicata was confirmed as relative abundance species compared to the SARS-CoV2 delta (B.1.617.2) variant only-infected group. 결론: The composition of gut microbiota was initially different from that of control in early phase, especially in severe diseases group. In late phase, the gut dysbiosis was almostly recovered to its baseline composition. The predominant opportunistic pathogens can be used as a biomarker of severity prediction. [ABSTRACT FROM AUTHOR]

Arbuscular myconhizal fungi (AMF) are ubiquitous in the rhizosphere and form symbiotic relationships with most terrestrial plant roots. In this study, four strains of Rhizophagus clarus were cultured and variations in their growth characteristics owing to functional diversity and resultant effects on host plant were investigated. Growth characteristics of the studied R. clarus strains varied significantly, suggesting that AMF retain high genetic variability at the intraspecies level despite asexual lineage. Furthermore, host plant growth response to the R. clarus strains showed that genetic variability in AMF could cause significant differences in the growth of the host plant, which prefers particular genetic types of fungal strains. These results suggest that the intraspecific genetic diversity of AMF could be result of similar selective pressure and may be expressed at a functional level. [ABSTRACT FROM AUTHOR]

In this study, we examined arbuscular mycorrhizal fungal (AMF) community structure colonizing field-cultivated ginseng roots according of different ages, such as 1- to 5-year-old plant, collected from Geumsan-gun, Korea. A total of seven AMF species namely, Funnelliformis caledonium, F. moseae, Gigaspora margarita, Paraglomus laccatum, P. occultum, Rhizophagus irregularis, and Scutellospora heterogama were identified from the roots using cloning, PCR-restriction fragment length polymorphism and sequence analysis of the large subunit region in rDNA. AMF species diversity in the ginseng roots decreased with the increase in root age because of the decreased species evenness. In addition, the community structures of AMF in the roots became more uniform. These results suggest that the age of ginseng affects mycorrhizal colonization and its community structure. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) have mutualistic relationships with more than 80% of terrestrial plant species. This symbiotic relationship is ancient and would have had important roles in establishment of plants on land. Despite their abundance and wide range of relationship with plant species, AMF have shown low species diversity. However, molecular studies have suggested that diversity of these fungi may be much higher, and genetic variation of AMF is very high within a species and even within a single spore. Despite low diversity and lack of host specificity, various functions have been associated with plant growth responses to arbuscular mycorrhizal fungal colonization. In addition, different community composition of AMF affects plants differently, and plays a potential role in ecosystem variability and productivity. AMF have high functional diversity because different combinations of host plants and AMF have different effects on the various aspects of symbiosis. Consequently, recent studies have focused on the different functions of AMF according to their genetic resource and their roles in ecosystem functioning. This review summarizes taxonomic, genetic, and functional diversities of AMF and their roles in natural ecosystems. [ABSTRACT FROM AUTHOR]

This study aimed to investigate differences in ectomycorrhizal (ECM) fungal communities between disturbed sites and undisturbed old forest sites. ECM root tips of Pinus densiflora were collected from 4 sites disturbed by human activities and 3 undisturbed old forest sites adjacent to the disturbed sites. Results in this study showed that the number of ECM root tips, species diversity and number of species were significantly higher in the disturbed sites than in the undisturbed sites, suggesting that the ECM fungal community structure was affected by the degree of disturbance. [ABSTRACT FROM AUTHOR]

In this study, the effect of soil ameliorators on ectomycorrhizal (ECM) fungal communities in coal mine spoils was investigated. Organic fertilizers and slaked lime were applied as soil ameliorators in 3 abandoned coal mine spoils. One year after the initial treatment, roots of Pinus densiflora seedlings were collected and the number of ECM species, colonization rate, and species diversity were assessed. The results showed that the soil ameliorators significantly increased ECM colonization on the roots of P. densiflora. The results suggest that soil ameliorators can have a positive effect on ECM fungi in terms of growth of host plants and show the potential use of soil ameliorator treatment for revegetation with ECM-colonized pine seedlings in the coal mine spoils. [ABSTRACT FROM AUTHOR]

Abstract Mounting evidence suggests that probiotics are beneficial for treating Alzheimer’s disease (AD). However, the mechanisms by which specific probiotics modify AD pathophysiology are not clearly understood. In this study, we investigated whether Lactobacillus paracasei-derived extracellular vesicles (Lpc-EV) can directly act on neuronal cells to modify amyloid-beta (Aβ)-induced transcriptional changes and Aβ pathology in the brains of Tg-APP/PS1 mice. Lpc-EV treatment in HT22 neuronal cells counteracts Aβ-induced downregulation of Brain-derived neurotrophic factor (Bdnf), Neurotrophin 3 (Nt3), Nt4/5, and TrkB receptor, and reverses Aβ-induced altered expression of diverse nuclear factors, including the downregulation of Methyl-CpG binding protein 2 (Mecp2) and Sirtuin 1 (Sirt1). Systematic siRNA-mediated knockdown experiments indicate that the upregulation of Bdnf, Nt3, Nt4/5, and TrkB by Lpc-EV is mediated via multiple epigenetic factors whose activation converges on Mecp2 and Sirt1. In addition, Lpc-EV reverses Aβ-induced downregulation of the Aβ-degrading proteases Matrix metalloproteinase 2 (Mmp-2), Mmp-9, and Neprilysin (Nep), whose upregulation is also controlled by MeCP2 and Sirt1. Lpc-EV treatment restores the downregulated expression of Bdnf, Nt4/5, TrkB, Mmp-2, Mmp-9, and Nep; induces the upregulation of MeCP2 and Sirt1 in the hippocampus; alleviates Aβ accumulation and neuroinflammatory responses in the brain; and mitigates cognitive decline in Tg-APP/PS1 mice. These results suggest that Lpc-EV cargo contains a neuroactive component that upregulates the expression of neurotrophic factors and Aβ-degrading proteases (Mmp-2, Mmp-9, and Nep) through the upregulation of MeCP2 and Sirt1, and ameliorates Aβ pathology and cognitive deficits in Tg-APP/PS1 mice.

The number of international students in South Korea, which dropped sharply during the COVID-19 pandemic, reached its highest level in 2023. It is predicted that the number of international students will continue to increase with the active growth in international exchange and due to diverse government support. This study introduces Padlet’s canvas layout in a class for international students to organize the course and boost engagement and interactions among the students and with the instructors. A survey and interviews with 22 undergraduate students from eight different countries, studying in Korea, were conducted to comprehend how they benefited from using the Padlet platform and their experience with it. The results indicate that Padlet enhances the students’ sense of belonging, expands their thinking processes through collaborative interactions and feedback from professors and colleagues, and increases their knowledge, leading to positive effects on class participation. Moreover, the use of Padlet accommodates diversity among different cultures and has a positive impact on cooperative learning in an international context. Based on these findings, several strategies for the implementation of Padlet in an educational setting can be suggested. To stimulate the participation of international students in learning, professors should consider offering the option of staying anonymous versus using real names when posting on Padlet. To improve the effectiveness of feedback, instructors should visualize their feedback. In addition, it is critical to institute guidelines to evaluate the relevance of the information in order to provide information that meets the students’ level of understanding and to establish a healthy level of information exchange. However, due to the limited sample size, the findings from this study cannot be generalized. Thus, we recommend expanding the sample in future studies to enable the use of inferential statistics, such as investigating differences in student attitudes by demographics.

HMGB1 is a prototypical danger-associated molecular pattern (DAMP) molecule that co-localizes with amyloid beta (Aβ) in the brains of patients with Alzheimer’s disease. HMGB1 levels are significantly higher in the cerebrospinal fluid of patients. However, the cellular and subcellular distribution of HMGB1 in relation to the pathology of Alzheimer’s disease has not yet been studied in detail. Here, we investigated whether HMGB1 protein levels in brain tissue homogenates (frontal cortex and striatum) and sera from Tg-APP/PS1 mice, along with its cellular and subcellular localization in those regions, differed. Total HMGB1 levels were increased in the frontal cortices of aged wildtype (7.5 M) mice compared to young (3.5 M) mice, whereas total HMGB1 levels in the frontal cortices of Tg-APP/PS1 mice (7.5 M) were significantly lower than those in age-matched wildtype mice. In contrast, total serum HMGB1 levels were enhanced in aged wildtype (7.5 M) mice and Tg-APP/PS1 mice (7.5 M). Further analysis indicated that nuclear HMGB1 levels in the frontal cortices of Tg-APP/PS1 mice were significantly reduced compared to those in age-matched wildtype controls, and cytosolic HMGB1 levels were also significantly decreased. Triple-fluorescence immunohistochemical analysis indicated that HMGB1 appeared as a ring shape in the cytoplasm of most neurons and microglia in the frontal cortices of 9.5 M Tg-APP/PS1 mice, indicating that nuclear HMGB1 is reduced by aging and in Tg-APP/PS1 mice. Consistent with these observations, Aβ treatment of both primary cortical neuron and primary microglial cultures increased HMGB1 secretion in the media, in an Aβ-dose-dependent manner. Our results indicate that nuclear HMGB1 might be translocated from the nucleus to the cytoplasm in both neurons and microglia in the brains of Tg-APP/PS1 mice, and that it may subsequently be secreted extracellularly.

Chronic stress induces maladaptive changes in the neural networks and it’s associated with mood disorders. Here, the authors show that repeated exposure to short-term stress can resolve pre-existing chronic stress induced depressive-like behaviour in mice.

We developed sociability tests based on use of a U-shaped two-choice field to read out behavioral states of sociability in rodents. The U-shaped two-choice field is a modified open field that is partially partitioned with a wall projecting to the central point, resulting in two symmetrical rectangular fields, each containing closed and open square zones that together form a ‘U-shaped field’. The U-shaped two-choice field can be used to measure animal’s behavioral responses to two contrasting or similar options, such as (i) a social target versus an inanimate object, (ii) a new stranger versus an earlier stranger, and (iii) a novel animal (a non-mate) versus a cage-mate (a familiar animal). We describe detailed procedures for sociability tests for the above three behavioral test paradigms based on the U-shaped two-choice field.