Cytokine and Chemokine Profiles in Acute Severe Fever with Thrombocytopenia Syndrome and Scrub Typhus in South Korea

In East Asia, severe fever with thrombocytopenia syndrome (SFTS) and scrub typhus, which are common endemic tick- and mite-mediated diseases sharing common clinical manifestations, are becoming public health concerns. However, there are limited data on the comparative immunopathogenesis between the two diseases. We compared the cytokine profiles of SFTS and scrub typhus to further elucidate immune responses that occur during the disease courses. We prospectively enrolled 44 patients with confirmed SFTS and 49 patients with scrub typhus from July 2015 to December 2020. In addition, 10 healthy volunteers were enrolled as healthy controls. A cytometric bead array was used to analyze plasma samples for 16 cytokines. A total of 68 plasma samples, including 31 (45.6%) from patients with SFTS and 37 (54.4%) from patients with scrub typhus, were available for cytokine measurement. There were three cytokine expression patterns: increased levels in both SFTS and scrub typhus (interleukin 6 [IL-6], IL-10, interferon gamma induced protein 10 [IP-10], and granulocyte-macrophage colony-stimulating factor [GM-CSF]), highest levels in SFTS (interferon alpha [IFN-α], IFN-γ, granulocyte-CSF [G-CSF], monocyte chemotactic protein 1 [MCP-1], macrophage inflammatory protein 1α [MIP-1α], and IL-8), and distinct levels in scrub typhus (IL-12p40, tumor necrosis factor alpha [TNFα], IL-1β, regulated on activation and normally T-cell expressed and secreted [RANTES], IL-17A, and vascular endothelial growth factor [VEGF]). Although patients with acute SFTS and scrub typhus exhibited partly shared expression patterns of cytokines related to disease severity, the different profiles of cytokines and chemokines might contribute to higher mortality in SFTS than in scrub typhus. Discrete patterns of helper T cell-related cytokines and VEGF might reflect differences in CD4 T-cell responses and vascular damage between these diseases.

Clinical characteristics and outcomes of Clostridioides difficile infection in the intensive care unit: a KASID multi-centre study

BACKGROUND

Despite the growing clinical and economic burden of Clostridioides difficile infection (CDI), data on CDI in the intensive care unit (ICU) in the Asia-Pacific region are lacking.

METHODS

This retrospective study analysed 191 patients who were treated with CDI in the ICUs of three hospitals in South Korea from January 2017 to May 2021. Backward-stepwise multiple logistic regression was used to identify factors influencing the treatment response and mortality.

RESULTS

Fifty-eight patients (30.4%) were considered immunocompromised. The mean Charlson comorbidity index was 5.65 ± 2.39 (10-year survival rate: 21%), the APACHE II score was 20.86 ± 7.78 (mortality rate: 40%), the ATLAS score was 5.45 ± 1.59 (cure rate: 75%), and the SOFA score was 7.97 ± 4.03 (mortality rate: 21.5%). Fifty-eight (30.4%) of the CDI cases were severe and 40 (20.9%) were fulminant. Oral vancomycin or oral metronidazole was the most frequently first-line treatments (N = 57; 32.6%). The 10-day response rate was 59.7% and the eight-week overall mortality rate was 41.4%. Fulminant CDI (OR 0.230; 95% CI 0.085-0.623) and each one-unit increment in the SOFA score (OR 0.848; 95% CI 0.759-0.947) were associated with treatment failure. High APACHE II (OR 0.355; 95% CI 0.143-0.880) and SOFA (OR 0.164; 95% CI 0.061-0.441) scores were associated with higher mortality.

CONCLUSIONS

High-risk patients in the ICU had a higher mortality rate and a lower cure rate of CDI. Further research is required to provide more accurate prediction scoring systems and better clinical outcomes.

Growth Increase in the Herbaceous Plant Centella asiatica by the Plant Growth-Promoting Rhizobacteria Priestia megaterium HyangYak-01

Centella asiatica is a traditional herbaceous plant with numerous beneficial effects, widely known for its medicinal and cosmetic applications. Maximizing its growth can lead to beneficial effects, by focusing on the use of its active compounds. The use of plant growth-promoting rhizobacteria (PGPR) is known to be an alternative to chemical fertilizers. In this study, we used the PGPR Priestia megaterium HY-01 to increase the yield of C. asiatica. In vitro assays showed that HY-01 exhibited plant growth-promoting activities (IAA production, denitrification, phosphate solubilization, and urease activity). Genomic analyses also showed that the strain has plant growth-promoting-related genes that corroborate with the different PGP activities found in the assays. This strain was subsequently used in field experiments to test its effectiveness on the growth of C. asiatica. After four months of application, leaf and root samples were collected to measure the plant growth rate. Moreover, we checked the rhizosphere microbiome between the treated and non-treated plots. Our results suggest that treatment with Hyang-yak-01 not only improved the growth of C. asiatica (leaf length, leaf weight, leaf width, root length, root width, and chlorophyll content) but also influenced the rhizosphere microbiome. Biodiversity was higher in the treated group, and the bacterial composition was also different from the control group.

Ecoinformatic Analysis of the Gut Ecological Diversity of Wild and Captive Long-Tailed Gorals Using Improved ITS2 Region Primers to Support Their Conservation

Ex situ conservation is used to protect endangered wildlife. As captive and wild long-tailed gorals are known to be similar, individuals under ex situ conservation can be reintroduced into nature. However, there is no appropriate indicator to evaluate them. Here, we amplified the internal transcribed spacer 2 (ITS2) region and compared the gut ecological information (eco-information) of captive and wild long-tailed gorals. We validated the existing ITS86F and ITS4 universal primers using reference sequences of the National Center for Biotechnology Information (NCBI) and improved their matching rates. We compared the gut eco-information of captive and wild long-tailed gorals obtained through experiments using the improved primer pair and found that the gut ecological diversity of captive gorals was low. Based on this, we suggested that the gut eco-information can be used as an evaluation index before reintroducing captive long-tailed gorals. Furthermore, we identified four plant types from the gut eco-information of wild long-tailed gorals, which can be the additional food sources to enhance the reduced intestinal ecological diversity of the captive animals.

Immune Responses After Vaccination With Primary 2-Dose ChAdOx1 Plus a Booster of BNT162b2 or Vaccination With Primary 2-Dose BNT162b2 Plus a Booster of BNT162b2 and the Occurrence of Omicron Breakthrough Infection

BACKGROUND

Before the omicron era, health care workers were usually vaccinated with either the primary 2-dose ChAdOx1 nCoV-19 (Oxford-AstraZeneca) series plus a booster dose of BNT162b2 (Pfizer-BioNTech) (CCB group) or the primary 2-dose BNT162b2 series plus a booster dose of BNT162b2 (BBB group) in Korea.

METHODS

The two groups were compared using quantification of the surrogate virus neutralization test for wild type severe acute respiratory syndrome coronavirus 2 (SVNT-WT), the omicron variant (SVNT-O), spike-specific IgG, and interferon-gamma (IFN-γ), as well as the omicron breakthrough infection cases.

RESULTS

There were 113 participants enrolled in the CCB group and 51 enrolled in the BBB group. Before and after booster vaccination, the median SVNT-WT and SVNT-O values were lower in the CCB (SVNT-WT [before-after]: 72.02-97.61%, SVNT-O: 15.18-42.29%) group than in the BBB group (SVNT-WT: 89.19-98.11%, SVNT-O: 23.58-68.56%; all P < 0.001). Although the median IgG concentrations were different between the CCB and BBB groups after the primary series (2.677 vs. 4.700 AU/mL, respectively, P < 0.001), they were not different between the two groups after the booster vaccination (7.246 vs. 7.979 AU/mL, respectively, P = 0.108). In addition, the median IFN-γ concentration was higher in the BBB group than in the CCB group (550.5 and 387.5 mIU/mL, respectively, P = 0.014). There was also a difference in the cumulative incidence curves over time (CCB group 50.0% vs. BBB group 41.8%; P = 0.045), indicating that breakthrough infection occurred faster in the CCB group.

CONCLUSION

The cellular and humoral immune responses were low in the CCB group so that the breakthrough infection occurred faster in the CCB group than in the BBB group.

Hypoalbuminemia and Albumin Replacement during Extracorporeal Membrane Oxygenation in Patients with Cardiogenic Shock

Background

Extracorporeal membrane oxygenation (ECMO) has been widely used in patients with cardiorespiratory failure. The serum albumin level is an important prognostic marker in critically ill patients. We evaluated the efficacy of using pre-ECMO serum albumin levels to predict 30-day mortality in patients with cardiogenic shock (CS) who underwent venoarterial (VA) ECMO.

Methods

We reviewed the medical records of 114 adult patients who underwent VA-ECMO between March 2021 and September 2022. The patients were divided into survivors and non-survivors. Clinical data before and during ECMO were compared.

Results

Patients' mean age was 67.8±13.6 years, and 36 (31.6%) were female. The proportion of survival to discharge was 48.6% (n=56). Cox regression analysis showed that the pre-ECMO albumin level independently predicted 30-day mortality (hazard ratio, 0.25; 95% confidence interval [CI], 0.11-0.59; p=0.002). The area under the receiver operating characteristic curve of albumin levels (pre-ECMO) was 0.73 (standard error [SE], 0.05; 95% CI, 0.63-0.81; p<0.001; cut-off value=3.4 g/dL). Kaplan-Meier survival analysis showed that the cumulative 30-day mortality was significantly higher in patients with a pre-ECMO albumin level ≤3.4 g/dL than in those with a level >3.4 g/dL (68.9% vs. 23.8%, p<0.001). As the adjusted amount of albumin infused increased, the possibility of 30-day mortality also increased (coefficient=0.140; SE, 0.037; p<0.001).

Conclusion

Hypoalbuminemia during ECMO was associated with higher mortality, even with higher amounts of albumin replacement, in patients with CS who underwent VA-ECMO. Further studies are needed to predict the timing of albumin replacement during ECMO.

A study on changes in lung function, neutralizing antibodies, and symptoms of adult patients hospitalized with COVID-19

BACKGROUND/AIMS

To identify changes in symptoms and pulmonary sequelae in patients with coronavirus disease 2019 (COVID-19).

METHODS

Patients with COVID-19 hospitalized at seven university hospitals in Korea between February 2020 and February 2021 were enrolled, provided they had ≥ 1 outpatient follow-up visit. Between January 11 and March 9, 2021 (study period), residual symptom investigations, chest computed tomography (CT) scans, pulmonary function tests (PFT), and neutralizing antibody tests (NAb) were performed at the outpatient visit (cross-sectional design). Additionally, data from patients who already had follow-up outpatient visits before the study period were collected retrospectively.

RESULTS

Investigation of residual symptoms, chest CT scans, PFT, and NAb were performed in 84, 35, 31, and 27 patients, respectively. After 6 months, chest discomfort and dyspnea persisted in 26.7% (4/15) and 33.3% (5/15) patients, respectively, and 40.0% (6/15) and 26.7% (4/15) patients experienced financial loss and emotional distress, respectively. When the ratio of later CT score to previous ones was calculated for each patient between three different time intervals (1-14, 15-60, and 61-365 days), the median values were 0.65 (the second interval to the first), 0.39 (the third to the second), and 0.20 (the third to the first), indicating that CT score decreases with time. In the high-severity group, the ratio was lower than in the low-severity group.

CONCLUSION

In COVID-19 survivors, chest CT score recovers over time, but recovery is slower in severely ill patients. Subjects complained of various ongoing symptoms and socioeconomic problems for several months after recovery.

Relationship between SARS-CoV-2 antibody titer and the severity of COVID-19

BACKGROUND

It remains unclear whether high titers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies aggravate clinical manifestations in patients or whether severe clinical manifestations result in high antibody titers. Thus, we investigated the cause-effect relationship between SARS-CoV-2 antibody titers and disease severity.

METHODS

We prospectively enrolled patients admitted with the diagnosis of coronavirus disease-19 (COVID-19) from February 2020 to August 2020. We measured SARS-CoV-2 antibody titers, namely anti-receptor-binding domain (RBD) antibody and neutralizing antibody (NAb), from blood samples and calculated the chest radiograph (CXR) scores of the patients to evaluate the severity of COVID-19.

RESULTS

Overall, 40 patients with COVID-19 were enrolled. Pneumonia was observed in more than half of the patients (25/40, 60%). SARS-CoV-2 antibody titers were higher in patients who were aged >60 years (anti-RBD antibodies, P = 0.003 and NAb, P = 0.009), presented with pneumonia (P = 0.006 and 0.007, respectively), and required oxygen therapy (P = 0.003 and 0.004, respectively) than in those who were not. CXR scores peaked (at 15-21 days after the onset of symptoms) statistically significantly earlier than SARS-CoV-2 antibody titers (at 22-30 days for NAb and at 31-70 days for anti-RBD antibody). There was a close correlation between the maximum CXR score and the maximum SAR-CoV-2 antibody titer.

CONCLUSIONS

Based on the comparison of the peak time of SARS-CoV-2 antibody titers with the CXR score after symptom onset, we suggest that severe clinical manifestations result in high titers of SARS-CoV-2 antibodies.

Development of mixed starter culture for the fermentation of Ethiopian honey wine, Tej

Ethiopian honey wine is one of the country's most popular spontaneously fermented traditional alcoholic beverages. However, the final product of this natural fermentation system is frequently of poor and inconsistent quality. Furthermore, it makes the process difficult to predict, control, and correct. Thus, the main aim of this study was to develop a direct fermentation system for Ethiopian honey wine, Tej. After isolating fermentative microbial strains from Tej samples, they were subjected to intensive screening to fit to its purpose. Later, phenotypic and genotypic characterization, and inoculation of isolates to honey-must were performed sequentially. Finally, microbial interaction and physicochemical analysis, including volatile compounds profiling, were done for the inoculated samples. The identified isolates were strains of Saccharomycetaceae and Lactobacillaceae families. These strains showed a good ability to tolerate osmotic stress and a lower pH environment. Tej sample produced by mixed culture inoculation of Saccharomyces and Lactobacillus species showed similar physicochemical, volatile compounds, and sensory attributes values with that of the control sample. Thus, a mixture of Saccharomyces and Lactobacillus strains could be used as a starter culture to produce Ethiopian honey, Tej, without scarifying of its major quality attributes.

Risk Factors for Coronavirus Disease 2019 (COVID-19)-Associated Pulmonary Aspergillosis in Critically Ill Patients: A Nationwide, Multicenter, Retrospective Cohort Study

BACKGROUND

Coronavirus disease 2019 (COVID-19) is often accompanied by secondary infections, such as invasive aspergillosis. In this study, risk factors for developing COVID-19-associated pulmonary aspergillosis (CAPA) and their clinical outcomes were evaluated.

METHODS

This multicenter retrospective cohort study included critically ill COVID-19 patients from July 2020 through March 2021. Critically ill patients were defined as patients requiring high-flow respiratory support or mechanical ventilation. CAPA was defined based on the 2020 European Confederation of Medical Mycology and the International Society for Human and Animal Mycology consensus criteria. Factors associated with CAPA were analyzed, and their clinical outcomes were adjusted by a propensity score-matched model.

RESULTS

Among 187 eligible patients, 17 (9.1%) developed CAPA, which is equal to 33.10 per 10,000 patient-days. Sixteen patients received voriconazole-based antifungal treatment. In addition, 82.4% and 53.5% of patients with CAPA and without CAPA, respectively, received early high-dose corticosteroids (P = 0.022). In multivariable analysis, initial 10-day cumulative steroid dose > 60 mg of dexamethasone or dexamethasone equivalent dose) (adjusted odds ratio [OR], 3.77; 95% confidence interval [CI], 1.03-13.79) and chronic pulmonary disease (adjusted OR, 4.20; 95% CI, 1.26-14.02) were independently associated with CAPA. Tendencies of higher 90-day overall mortality (54.3% vs. 35.2%, P = 0.346) and lower respiratory support-free rate were observed in patients with CAPA (76.3% vs. 54.9%, P = 0.089).

CONCLUSION

Our study showed that the dose of corticosteroid use might be a risk factor for CAPA development and the possibility of CAPA contributing to adverse outcomes in critically ill COVID-19 patients.

Development of a Chimeric Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-2 Vaccine Candidate Expressing Hypo-Glycosylated Glycoprotein-5 Ectodomain of Korean Lineage-1 Strain

Vaccination is a practical method to provide protection against porcine reproductive and respiratory syndrome virus (PRRSV), but current PRRSV vaccines show limited efficacy against divergent field strains. Lineage 1 PRRSV includes virulent strains such as NADC30 and MN184 and now has become one of the most prevalent viruses in Korea. Accordingly, there is an urgent need to develop a new vaccine for Korean lineage-1 strains. In this study, a vaccine candidate against Korean lineage-1 PRRSV, vCSL1-GP5-N33D, was developed by reverse genetics technology. vCSL1-GP5-N33D was designed as a hypo-glycosylated chimeric virus containing the glycoprotein 5 ectodomain region of the Korean lineage-1 wild-type strain. An inactivated vaccine of vCSL1-GP5-N33D was applied to a PRRS-endemic farm and elicited high serum virus neutralization (SVN) antibody titers. The vaccinated group induced SVN antibody titers of 4.40 (log₂) ± 2.46, which were approximately 2-fold higher than those of the negative control at 8-weeks post-vaccination. Moreover, 60% of pigs in the vaccinated group displayed SVN antibody titers of ≥5 (log₂), while none of the pigs in the negative control exhibited SVN antibody titers of ≥5 (log₂). The overall results of the animal experiment suggest that the vCSL1-GP5-N33D inactivated vaccine is a promising vaccine candidate.

Prediction of 6-Month Mortality Using Pre-Extracorporeal Membrane Oxygenation Lactate in Patients with Acute Coronary Syndrome Undergoing Veno-Arterial-Extracorporeal Membrane Oxygenation

Background

The effectiveness of extracorporeal membrane oxygenation (ECMO) for patients with refractory cardiogenic shock or cardiac arrest is being established, and serum lactate is well known as a biomarker of end-organ perfusion. We evaluated the efficacy of pre-ECMO lactate for predicting 6-month survival in patients with acute coronary syndrome (ACS) undergoing ECMO.

Methods

We reviewed the medical records of 148 patients who underwent veno-arterial (VA) ECMO for ACS between January 2015 and June 2020. These patients were divided into survivors and non-survivors based on 6-month survival. All clinical data before and during ECMO were compared between the 2 groups.

Results

Patients’ mean age was 66.0±10.5 years, and 116 (78.4%) were men. The total survival rate was 45.9% (n=68). Cox regression analysis showed that the pre-ECMO lactate level was an independent predictor of 6-month mortality (hazard ratio, 1.210; 95% confidence interval [CI], 1.064–1.376; p=0.004). The area under the receiver operating characteristic curve of pre-ECMO lactate was 0.64 (95% CI, 0.56–0.72; p=0.002; cut-off value=9.8 mmol/L). Kaplan-Meier survival analysis showed that the cumulative survival rate at 6 months was significantly higher among patients with a pre-ECMO lactate level of 9.8 mmol/L or less than among those with a level exceeding 9.8 mmol/L (57.3% vs. 31.8%, p=0.0008).

Conclusion

A pre-ECMO lactate of 9.8 mmol/L or less may predict a favorable outcome at 6 months in ACS patients undergoing VA-ECMO. Further research aiming to improve the accuracy of predictions of reversibility in patients with high pre-ECMO lactate levels is essential.

Rhinovirus Incidence Rates Indicate We Are Tired of Non-pharmacological Interventions Against Coronavirus Disease 2019

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, the incidence of rhinovirus (RV) is inversely related to the intensity of non-pharmacological interventions (NPIs), such as universal mask wearing and physical distancing.

METHODS

Using RV surveillance data, changes in the effect of NPIs were investigated in South Korea during the pandemic. The time to the first visible effect of NPIs after the onset of NPIs (T1), time to the maximum effect (T2), and duration of the maximum effect (T3) were measured for each surge. For each week, the RVdiff [(RV incidence during the pandemic) - (RV incidence within 5 years before the pandemic)] was calculated, and number of weeks for RVdiff to be below zero after NPIs (time to RVdiff ≤ 0) and number of weeks RVdiff remains below zero after NPIs (duration of RVdiff ≤ 0) were measured for each surge.

RESULTS

During the study period, four surges of COVID-19 were reported. As the pandemic progressed, T1 and T2 increased, but T3 decreased. Additionally, the "time to RVdiff of ≤ 0" increased and "duration of RVdiff of ≤ 0" decreased. These changes became more pronounced during the third surge (mid-November 2020), before the introduction of the COVID-19 vaccine, and from the emergence of the delta variant.

CONCLUSION

The effect of NPIs appears slower, the duration of the effect becomes shorter, and the intensity also decreases less than a year after the onset of the pandemic owing to people's exhaustion in implementing NPIs. These findings suggest that the COVID-19 response strategy must be completely overhauled.

Enhanced cross protection by hetero prime-boost vaccination with recombinant influenza viruses containing chimeric hemagglutinin-M2e epitopes

Annual repeat influenza vaccination raises concerns about protective efficacy against mismatched viruses. We investigated the impact of heterologous prime-boost vaccination on inducing cross protection by designing recombinant influenza viruses with chimeric hemagglutinin (HA) carrying M2 extracellular domains (M2e-HA). Heterologous prime-boost vaccination of C57BL/6 mice with M2e-HA chimeric virus more effectively induced M2e and HA stalk specific IgG antibodies correlating with cross protection than homologous prime-boost vaccination. Induction of M2e and HA stalk specific IgG antibodies was compromised in 1-year old mice, indicating significant aging effects on priming subdominant M2e and HA stalk IgG antibody responses. This study demonstrates that a heterologous prime-boost strategy with recombinant influenza virus expressing extra M2e epitopes provides more effective cross protection than homologous vaccination.

Viral and Immunologic Factors Associated with Fatal Outcome of Patients with Severe Fever with Thrombocytopenia Syndrome in Korea

Significant progress has been made on the molecular biology of the severe fever with thrombopenia virus (SFTSV); however, many parts of the pathophysiological mechanisms of mortality in SFTS remain unclear. In this study, we investigated virologic and immunologic factors for fatal outcomes of patients with SFTS. We prospectively enrolled SFTS patients admitted from July 2015 to October 2020. Plasma samples were subjected to SFTSV RNA RT-PCR, multiplex microbead immunoassay for 17 cytokines, and IFA assay. A total of 44 SFTS patients were enrolled, including 37 (84.1%) survivors and 7 (15.9%) non-survivors. Non-survivors had a 2.5 times higher plasma SFTSV load than survivors at admission (p < 0.001), and the viral load in non-survivors increased progressively during hospitalization. In addition, non-survivors did not develop adequate anti-SFTSV IgG, whereas survivors exhibited anti-SFTSV IgG during hospitalization. IFN-α, IL-10, IP-10, IFN-γ, IL-6, IL-8, MCP-1, MIP-1α, and G-CSF were significantly elevated in non-survivors compared to survivors and did not revert to normal ranges during hospitalization (p < 0.05). Severe signs of inflammation such as a high plasma concentration of IFN-α, IL-10, IP-10, IFN-γ, IL-6, IL-8, MCP-1, MIP-1α, and G-CSF, poor viral control, and inadequate antibody response during the disease course were associated with mortality in SFTS patients.

Risk factors for isolation of multi-drug resistant organisms in coronavirus disease 2019 pneumonia: A multicenter study

Objectives

Superimposed multi-drug resistant organisms (MDROs) co-infection can be associated with worse outcomes in patients with severe coronavirus disease 2019 (COVID-19), even if these patients were managed with strict airborne and contact precautions. Identifying risk factors for isolation of MDROs is critical to COVID-19 treatment.

Methods

All eligible adult patients with confirmed COVID-19 pneumonia from 10 hospitals in the Republic of Korea between February 2020 and May 2020 were retrospectively enrolled. Using this cohort, epidemiology and risk factors for isolation of MDROs were evaluated.

Results

Of 152 patients, 47 with microbial culture results were included. Twenty isolates of MDROs from 13 (28%) patients were cultured. Stenotrophomonas maltophilia (5 isolates) was the most common MDRO, followed by methicillin-resistant staphylococcus aureus (4 isolates). MDROs were mostly isolated from sputum samples (80%, 16/20). The median time from hospitalization to MDRO isolation was 28 days (interquartile range, 18-38 days). In-hospital mortality was higher in patients with MDRO isolation (62% vs 15%; P = .001). Use of systemic corticosteroids after diagnosis of COVID-19 (adjusted odds ratio [aOR]: 15.07; 95% confidence interval [CI]: 2.34-97.01; P = .004) and long-term care facility (LTCF) stay before diagnosis of COVID-19 (aOR: 6.09; 95% CI: 1.02-36.49; P = .048) were associated with MDRO isolation.

Conclusions

MDROs were isolated from 28% of COVID-19 pneumonia patients with culture data and 8.6% of the entire cohort. Previous LTCF stay and adjunctive corticosteroid use were risk factors for the isolation of MDROs. Strict infection prevention strategies may be needed in these COVID-19 patients with risk factors.

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.

Alteration of the Soil Microbiota in Ginseng Rusty Roots: Application of Machine Learning Algorithm to Explore Potential Biomarkers for Diagnostic and Predictive Analytics

Conceptualization to utilize microbial composition as a prediction tool has been widely applied in human cohorts, yet the potential capacity of soil microbiota as a diagnostic tool to predict plant phenotype remains unknown. Here, we collected 130 soil samples which are 54 healthy controls and 76 ginseng rusty roots (GRRs). Alpha diversities including Shannon, Simpson, Chao1, and phylogenetic diversity were significantly decreased in GRR (P < 0.05). Moreover, we identified 30 potential biomarkers. The optimized markers were obtained through fivefold cross-validation on a support vector machine and yielded a robust area under the curve of 0.856. Notably, evaluation of multi-index classification performance including accuracy, F1-score, and Kappa coefficient also showed robust discriminative capability (90.99%, 0.903, and 0.808). Taken together, our results suggest that the disease affects the microbial community and offers the potential ability of soil microbiota to identifying farms at the risk of GRR.

Single dose of multi-clade virus-like particle vaccine protects chickens against clade 2.3.2.1 and clade 2.3.4.4 highly pathogenic avian influenza viruses

Virus-like particles (VLPs) are recognized as an alternative vaccine platform that provide effective protection against various highly pathogenic avian influenza viruses (HPAIVs). Here, we developed multi-clade VLPs expressing two HAs (a chimera of clade 2.3.2.1c and clade 2.3.4.4c HA) within a single vector. We then compared its protective efficacy with that of a monovalent VLP and evaluated its potency against each homologous strain. Chickens vaccinated with the multi-clade VLP shed less virus and were better protected against challenge than birds receiving monovalent vaccines. Single vaccination with a multi-clade VLP resulted in 100% survival, with no clinical symptoms and high levels of pre-challenge protective immunity (7.6–8.5 log₂). Moreover, the multi-clade VLP showed high productivity (128–256 HAU) both in the laboratory and on a large scale, making it cheaper than whole inactivated vaccines produced in eggs. However, the PD₅₀ (protective dose 50%) of the multi-clade VLP against clades 2.3.2.1c and 2.3.4.4c was < 50 PD₅₀ (28 and 42 PD₅₀, respectively), and effective antibody response was maintained for 2–3 months. This multi-clade VLP protects against both clades of HPAI viruses and can be produced in high amounts at low cost. Thus, the vaccine has potential as a pandemic preparedness vaccine.

Systemic Adverse Events and Use of Antipyretics Predict the Neutralizing Antibody Positivity Early after the First Dose of ChAdOx1 Coronavirus Disease Vaccine

Vaccination is considered crucial for the eradication of the coronavirus disease (COVID-19). In our medical center in Korea, most health care workers (HCWs) were vaccinated with the ChAdOx1 COVID-19 vaccine. After vaccination, many HCWs complained of adverse events (AEs). However, it remains unclear whether the production of neutralizing antibodies (NAb) was affected. Therefore, here, we aimed to evaluate AEs and early NAb production in relatively healthy Asians who received the ChAdOx1 vaccine and determine the effect of AEs and antipyretics on early NAb production against COVID-19. Of the 182 Korean HCWs who received the first dose of ChAdOx1 vaccine, 172 (94.5%) experienced ≥1 adverse events and 148 (81.3%) tested positive for NAb 33–40 days after the vaccination. NAb-positive vaccine recipients reported systemic AEs and consumed acetaminophen more frequently than NAb-negative recipients. We identified an association between antibody response and COVID-19 vaccine-related AEs. In conclusion, most ChAdOx1 vaccine recipients reported AEs in our medical center.

SARS-CoV-2-Specific Antibody and T Cell Response Kinetics According to Symptom Severity

Data on the longevity of humoral and cell-mediated immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with coronavirus disease 2019 (COVID-19) are limited. We evaluated the detailed kinetics of antibody and T-cell responses at the acute, convalescent, and post-convalescent phases in COVID-19 patients with a wide range of severity. We enrolled patients with COVID-19 prospectively from four hospitals and one community treatment center between February 2020 and January 2021. symptom severity was classified as mild, moderate, or severe/critical. Patient blood samples were collected at 1 week (acute), 1 month (convalescent), and 2 months after symptom onset (post-convalescent). Human SARS-CoV-2 IgG and IgM antibodies were measured using in-house-developed ELISA. The SARS-CoV-2-specific T-cell responses against overlapping peptides of spike proteins and nucleoprotein were measured by interferon-γ enzyme-linked immunospot assays. Twenty-five COVID-19 patients were analyzed (mild, n = 5; moderate, n = 9; severe/critical, n = 11). IgM and IgG antibody responses peaked at 1 month after symptom onset and decreased at 2 months. IgG response levels were significantly greater in the severe/critical group compared with other groups. Interferon-γ-producing T-cell responses increased between 1 week and 1 month after symptom onset, and had a trend toward decreasing at 2 months, but did not show significant differences according to severity. Our data indicate that SARS-CoV-2-specific antibody responses were greater in those with severe symptoms and waned after reaching a peak around 1 month after symptom onset. However, SARS-CoV-2-specific T-cell responses were not significantly different according to symptom severity, and decreased slowly during the post-convalescent phase.

Effect of a bioconverted product of Lotus corniculatus seed on the axillary microbiome and body odor

The skin microbiome, especially the axillary microbiome, consists of odor-causing bacteria that decompose odorless sweat into malodor compounds, which contributes to the formation of body odor. Plant-derived products are a cheap source of bioactive compounds that are common ingredients in cosmetics. Microbial bioconversion of natural products is an ecofriendly and economical method for production of new or improved biologically active compounds. Therefore, in this study, we tested the potential of a Lactobacillus acidophilus KNU-02-mediated bioconverted product (BLC) of Lotus corniculatus seed to reduce axillary malodor and its effect on the associated axillary microbiota. A chemical profile analysis revealed that benzoic acid was the most abundant chemical compound in BLC, which increased following bioconversion. Moreover, BLC treatment was found to reduce the intensity of axillary malodor. We tested the axillary microbiome of 18 study participants, divided equally into BLC and placebo groups, and revealed through 16S rRNA gene sequencing that Staphylococcus, Corynebacterium, and Anaerococcus were the dominant taxa, and some of these taxa were significantly associated with axillary malodor. After one week of BLC treatment, the abundance of Corynebacterium and Anaerococcus, which are associated with well-known odor-related genes that produce volatile fatty acids, had significantly reduced. Likewise, the identified odor-related genes decreased after the application of BLC. BLC treatment enhanced the richness and network density of the axillary microbial community. The placebo group, on the other hand, showed no difference in the microbial richness, odor associated taxa, and predicted functional genes after a week. The results demonstrated that BLC has the potential to reduce the axillary malodor and the associated odor-causing bacteria, which makes BLC a viable deodorant material in cosmetic products.

The 2019-2020 EURADOS WG10 and RENEB Field Test of Retrospective Dosimetry Methods in a Small-Scale Incident Involving Ionizing Radiation

With the use of ionizing radiation comes the risk of accidents and malevolent misuse. When unplanned exposures occur, there are several methods which can be used to retrospectively reconstruct individual radiation exposures; biological methods include analysis of aberrations and damage of chromosomes and DNA, while physical methods rely on luminescence (TL/OSL) or EPR signals. To ensure the quality and dependability of these methods, they should be evaluated under realistic exposure conditions. In 2019, EURADOS Working Group 10 and RENEB organized a field test with the purpose of evaluating retrospective dosimetry methods as carried out in potential real-life exposure scenarios. A 1.36 TBq 192Ir source was used to irradiate anthropomorphic phantoms in different geometries at doses of several Gy in an outdoor open-air geometry. Materials intended for accident dosimetry (including mobile phones and blood) were placed on the phantoms together with reference dosimeters (LiF, NaCl, glass). The objective was to estimate radiation exposures received by individuals as measured using blood and fortuitous materials, and to evaluate these methods by comparing the estimated doses to reference measurements and Monte Carlo simulations. Herein we describe the overall planning, goals, execution and preliminary outcomes of the 2019 field test. Such field tests are essential for the development of new and existing methods. The outputs from this field test include useful experience in terms of planning and execution of future exercises, with respect to time management, radiation protection, and reference dosimetry to be considered to obtain relevant data for analysis.

Long-term cardiac outcomes of depression screening, diagnosis and treatment in patients with acute coronary syndrome: the DEPACS study

BACKGROUND

To investigate the impacts of depression screening, diagnosis and treatment on major adverse cardiac events (MACEs) in acute coronary syndrome (ACS).

METHODS

Prospective cohort study including a nested 24-week randomised clinical trial for treating depression was performed with 5-12 years after the index ACS. A total of 1152 patients recently hospitalised with ACS were recruited from 2006 to 2012, and were divided by depression screening and diagnosis at baseline and 24-week treatment allocation into five groups: 651 screening negative (N), 55 screening positive but no depressive disorder (S), 149 depressive disorder randomised to escitalopram (E), 151 depressive disorder randomised to placebo (P) and 146 depressive disorder receiving medical treatment only (M).

RESULTS

Cumulative MACE incidences over a median 8.4-year follow-up period were 29.6% in N, 43.6% in S, 40.9% in E, 53.6% in P and 59.6% in M. Compared to N, screening positive was associated with higher incidence of MACE [adjusted hazards ratio 2.15 (95% confidence interval 1.63-2.83)]. No differences were found between screening positive with and without a formal depressive disorder diagnosis. Of those screening positive, E was associated with a lower incidence of MACE than P and M. M had the worst outcomes even compared to P, despite significantly milder depressive symptoms at baseline.

CONCLUSIONS

Routine depression screening in patients with recent ACS and subsequent appropriate treatment of depression could improve long-term cardiac outcomes.

A prospective, multicentre, randomised, open-label trial to compare the efficacy and safety of clopidogrel versus ticagrelor in stabilised patients with acute myocardial infarction after percutaneous coronary intervention: rationale and design of the TALOS-AMI trial

AIMS

In patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), the risk of ischaemic complications is highest in the early phase (during the first 30 days), while most bleeding events occur predominantly during the maintenance phase of treatment (after the first 30 days). Data on the de-escalation of dual antiplatelet therapy by switching from ticagrelor to clopidogrel in stabilised AMI patients are limited. The aim of this study is to investigate the efficacy and safety of switching from ticagrelor to clopidogrel in AMI patients with no adverse event during the first month after the index PCI with newer-generation DES.

METHODS AND RESULTS

TALOS-AMI is a multicentre, randomised, open-label study enrolling 2,590 AMI patients with no adverse events during the first month after the index PCI. One month after the index PCI, eligible patients are randomly assigned either to 1) aspirin 100 mg plus clopidogrel 75 mg daily, or to 2) aspirin 100 mg plus ticagrelor 90 mg twice daily, in a 1:1 ratio. The primary endpoint is a composite of cardiovascular death, MI, stroke, and bleeding type 2, 3 or 5 according to the Bleeding Academic Research Consortium (BARC) criteria from 1 to 12 months after the index PCI.

CONCLUSIONS

The TALOS-AMI trial is the first large-scale, multicentre, randomised study exploring the efficacy and safety of the de-escalation of antiplatelet therapy by switching from ticagrelor to clopidogrel in stabilised AMI patients undergoing PCI.

Broad cross protection by recombinant live attenuated influenza H3N2 seasonal virus expressing conserved M2 extracellular domain in a chimeric hemagglutinin

Hemagglutinin (HA)-based current vaccines provide suboptimum cross protection. Influenza A virus contains an ion channel protein M2 conserved extracellular domain (M2e), a target for developing universal vaccines. Here we generated reassortant influenza virus rgH3N2 4xM2e virus (HA and NA from A/Switzerland/9715293/2013/(H3N2)) expressing chimeric 4xM2e-HA fusion proteins with 4xM2e epitopes inserted into the H3 HA N-terminus. Recombinant rgH3N2 4xM2e virus was found to retain equivalent growth kinetics as rgH3N2 in egg substrates. Intranasal single inoculation of mice with live rgH3N2 4xM2e virus was effective in priming the induction of M2e specific IgG antibody responses in mucosal and systemic sites as well as T cell responses. The rgH3N2 4xM2e primed mice were protected against a broad range of different influenza A virus subtypes including H1N1, H3N2, H5N1, H7N9, and H9N2. The findings support a new approach to improve the efficacy of current vaccine platforms by recombinant influenza virus inducing immunity to HA and cross protective M2e antigens.

Covalent Linkage and Macrocylization Preserve and Enhance Synergistic Interactions in Catalytic Amyloids

The self-assembly of short peptides into catalytic amyloid-like nanomaterials has proven to be a powerful tool in both understanding the evolution of early proteins and identifying new catalysts for practically useful chemical reactions. Here we demonstrate that both parallel and antiparallel arrangements of β-sheets can accommodate metal ions in catalytically productive coordination environments. Moreover, synergistic relationships, identified in catalytic amyloid mixtures, can be captured in macrocyclic and sheet-loop-sheet species, that offer faster rates of assembly and provide more complex asymmetric arrangements of functional groups, thus paving the way for future designs of amyloid-like catalytic proteins. Our findings show how initial catalytic activity in amyloid assemblies can be propagated and improved in more-complex molecules, providing another link in a complex evolutionary chain between short, potentially abiotically produced peptides and modern-day enzymes.

A Strategy to Elicit M2e-Specific Antibodies Using a Recombinant H7N9 Live Attenuated Influenza Vaccine Expressing Multiple M2e Tandem Repeats

Influenza viruses remain a serious public health problem. Vaccination is the most effective way to prevent the disease; however, seasonal influenza vaccines demonstrate low or no effectiveness against antigenically drifted and newly emerged influenza viruses. Different strategies of eliciting immune responses against conserved parts of various influenza virus proteins are being developed worldwide. We constructed a universal live attenuated influenza vaccine (LAIV) candidate with enhanced breadth of protection by modifying H7N9 LAIV by incorporating four epitopes of M2 protein extracellular part into its hemagglutinin molecule. The new recombinant H7N9+4M2e vaccine induced anti-M2e antibody responses and demonstrated increased protection against heterosubtypic challenge viruses in direct and serum passive protection studies, compared to the classical H7N9 LAIV. The results of our study suggest that the H7N9+4M2e warrants further investigation in pre-clinical and phase 1 clinical trials.

Kinetics of Serological Response in Patients with Severe Fever with Thrombocytopenia Syndrome

Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV). We investigated the detailed kinetics of serologic response in patients with SFTS. Twenty-eight patients aged ≥18 years were enrolled between July 2015 and October 2018. SFTS was confirmed by detecting SFTSV RNA in their plasma using reverse transcription polymerase chain reaction. SFTSV-specific IgG and IgM were measured using immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA). We found that SFTSV-specific IgG was detected at days 5–9 after symptom onset, and its titer was rising during the course of disease. SFTSV-specific IgM titer peaked at around week 2–3 from symptom onset. The SFTSV-specific seropositive rates for days 5–9, 10–14, 15–19, and 20–24 from symptom onset using IFA and ELISA were 63%, 76%, 90%, and 100%, and 58%, 86%, 100%, and 100%, respectively, for IgG, whereas they were 32%, 62%, 80%, and 100%, and 53%, 62%, 70%, and 100%, respectively, for IgM. The delayed IgM response could be attributed to the low sensitivity of SFTSV-specific IgM IFA or ELISA and/or impaired immune responses. The IgM test using IFA or ELISA that we used in this study is, therefore, insufficient for the early diagnosis of SFTS.

Effect of hydroxychloroquine pre-exposure on infection with SARS-CoV-2 in rheumatic disease patients: a population-based cohort study

Objectives

Early in vitro studies have suggested that hydroxychloroquine (HCQ) is a potentially useful drug against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. This study was conducted to determine whether HCQ had a preventive effect on coronavirus disease 2019 (COVID-19) in rheumatic disease patients who were taking HCQ.

Methods

We conducted a population-based retrospective cohort study using the records of the Korean Health Insurance Review and Assessment (HIRA) claim records. The clinical data of patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) who were tested for SARS-CoV-2 were investigated. We compared the attack rate of COVID-19 between those who underwent HCQ therapy within 14 days before the test for SARS-CoV-2 (HCQ users) and HCQ non-users. Data were analysed using logistic regression models, χ², and Student's t-tests.

Results

As of 15th May 2020, 2066 patients with RA or SLE were tested for COVID-19. Among them, 31.4% (649/2066) were treated with HCQ. Most HCQ users (93.7%, 608/649) were taking 200–400 mg/day recommended for the treatment of rheumatic diseases. The attack rate of COVID-19 in the HCQ users (2.3%, 15/649) did not differ from that in the HCQ non-users (2.2%, 31/1417) (p 0.86).

Conclusions

HCQ prophylactic use at a usual dose did not prevent COVID-19 in patients with rheumatic disease.

Factors of Severity in Patients with COVID-19: Cytokine/Chemokine Concentrations, Viral Load, and Antibody Responses

The severity of COVID-19 ranges from mild to critical diseases. However, limited data have been published on the detailed kinetics of viral load and host immune response throughout the disease course depending on disease severity. In this study, we comprehensively analyzed viral load, antibody responses to SARS-CoV-2, and cytokines/chemokines during the disease course, and identified the factors related to severity. Nasopharyngeal (NP) and plasma specimens were obtained from 31 patients with COVID-19 during hospitalization. Viral RNA in NP specimens was quantified by reverse transcription-PCR. Anti-SARS-CoV-2 antibodies and cytokines/chemokines in plasma specimens were analyzed by ELISA and cytometric bead array. The viral load in patients with COVID-19 peaked at the early stage of the disease and continuously decreased. Severe and critical cases showed higher viral load and prolonged viral shedding than asymptomatic and mild cases. Whereas plasma IgG was gradually increased and maintained during hospitalization, plasma IgM peaked at 3 weeks after symptom onset and dissipated. The antibody response in severe and critical cases was slightly delayed but stronger than those in others. High levels of interferon (IFN)-α, IFN-γ-induced protein-10, monokine induced by IFN-γ, and interleukin-6 at 5-10 days from symptom onset were associated with the severity of COVID-19. Our data indicate that high viral load in the respiratory tract and excessive production of cytokines and chemokines between 1 and 2 weeks from the symptom onset were significantly associated with the severity of COVID-19.

Quorum Sensing System Affects the Plant Growth Promotion Traits of Serratia fonticola GS2

Quorum sensing (QS) enables bacteria to organize gene expression programs, thereby coordinating collective behaviors. It involves the production, release, and population-wide detection of extracellular signaling molecules. The cellular processes regulated by QS in bacteria are diverse and may be used in mutualistic coordination or in response to changing environmental conditions. Here, we focused on the influence of the QS-dependent genes of our model bacterial strain Serratia fonticola GS2 on potential plant growth promoting (PGP) activities including indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and biofilm formation. Based on genomic and phenotypic experimental data we identified and investigated the function of QS genes in the genome of the model strain. Our gene deletion study confirmed the biological functionality of the QS auto-inducer (gloI) and receptor (gloR) on potential PGP activities of GS2. A transcriptomic approach was also undertaken to understand the role of QS genes in regulation of genes primarily involved in PGP activities (IAA, ACC deaminase activity, and biofilm formation). Both transcriptomic and phenotypic data revealed that the QS-deletion mutants had considerably less PGP activities, as compared to the wild type. In addition, in vivo plant experiments showed that plants treated with GS2 had significantly higher growth rates than plants treated with the QS-deletion mutants. Overall, our results showed how QS-dependent genes regulate the potential PGP activities of GS2. This information may be helpful in understanding the relationship between QS-dependent genes and the PGP activity of bacteria, which aid in the production of practical bio-fertilizers for plant growth promotion.

The Mechanism of Bisdemethoxycurcumin Enhances Conventional Antibiotics against Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) infection has posed a serious threat to public health, therefore, the development of new antibacterial drugs is imperative. Bisdemethoxycurcumin (BDMC) is a curcumin analog that exists in nature and possesses extensive pharmacological actions. This review focuses on investigating the antibacterial activity of BDMC alone or in combination with three antibiotics against MRSA. We determined the minimal inhibitory concentration of BDMC, with a broth microdilution assay, and the value against all six strains was 7.8 μg/mL. The synergistic effect of BDMC combined with the antibiotics was determined using a checkerboard dilution test and a time–kill curve assay. The results showed that the antimicrobial effect of BDMC combined with antibiotics was superior to treatment with that of a single agent alone. We examined the antibacterial activity of BDMC in the presence of a membrane-permeabilizing agent and an ATPase-inhibiting agent, respectively. In addition, we analyzed the mecA transcription gene and the penicillin-binding protein 2a (PBP2a) level of MRSA treated with BDMC by quantitative RT-PCR or Western blot assay. The gene transcription and the protein level were significantly inhibited. This study demonstrated that BDMC has potent antibacterial activity, and proved that BDMC may be a potential natural modulator of antibiotics.

Antibody kinetics and serologic profiles of SARS-CoV-2 infection using two serologic assays

Background

Coronavirus disease 2019 (COVID-19) is an emerging threat worldwide. This study aims to assess the serologic profiles and time kinetics of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with COVID-19 using two immunoassays.

Methods

A total of 97 samples serially collected from 17 patients with COVID-19 and 137 negative control samples were analyzed for IgM and IgG against SARS-CoV-2 using the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI^™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA).

Results

With both assays, IgM and IgG rapidly increased after 7 days post symptom onset (PSO). IgM antibody levels reached a peak at 15–35 d PSO and gradually decreased. IgG levels gradually increased and remained at similar levels after 22–35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO were 21.4%/35.7~57.1% and increased to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI^™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 negative controls, 12 samples (8.8%) showed positive or indeterminate results.

Conclusions

The antibody kinetics against SARS-CoV-2 are similar to common findings of acute viral infectious diseases. Antibody testing is useful for ruling out SARS-CoV-2 infection after 14 d PSO, detecting past infection, and epidemiologic surveys.

Utility of Magnetic Resonance Imaging for Differentiating Necrotizing Fasciitis from Severe Cellulitis: A Magnetic Resonance Indicator for Necrotizing Fasciitis (MRINEC) Algorithm

We developed a new magnetic resonance indicator for necrotizing fasciitis (MRINEC) algorithm for differentiating necrotizing fasciitis (NF) from severe cellulitis (SC). All adults with suspected NF between 2010 and 2018 in a tertiary hospital in South Korea were enrolled. Sixty-one patients were diagnosed with NF and 28 with SC. Among them, 34 with NF and 15 with SC underwent magnetic resonance imaging (MRI). The MRINEC algorithm, a two-step decision tree including T2 hyperintensity of intermuscular deep fascia and diffuse T2 hyperintensity of deep peripheral fascia, diagnosed NF with 94% sensitivity (95% confidence interval (CI), 80–99%) and 60% specificity (95% CI, 32–84%). The algorithm accurately diagnosed all 15 NF patients with a high (≥8) laboratory risk indicator for necrotizing fasciitis (LRINEC) score. Among the five patients with an intermediate (6–7) LRINEC score, sensitivity and specificity were 100% (95% CI, 78–100%) and 0% (95% CI, 0–84%), respectively. Finally, among the 29 patients with a low (≤5) LRINEC score, the algorithm had a sensitivity and specificity of 88% (95% CI, 62–98%) and 69% (95% CI, 39–91%), respectively. The MRINEC algorithm may be a useful adjuvant method for diagnosing NF, especially when NF is suspected in patients with a low LRINEC score.

Synergistic Interactions Are Prevalent in Catalytic Amyloids

Interactions between multiple functional groups are key to catalysis. Previously, we reported synergistic interactions in catalytic amyloids formed by mixtures of heptameric peptides that lead to significant improvements in esterase activity. Herein, we describe the in-depth investigation of synergistic interactions within a family of amyloid fibrils, exploring the results of functional group interactions, the effects of chirality and the use of mixed enantiomers within fibrils. Remarkably, we find that synergistic interactions (either positive or negative) are found in the vast majority of binary mixtures of catalytic amyloid-forming peptides. The productive arrangements of functionalities rapidly identified by mixing different peptides will undoubtedly lead to the development of more active catalysts for a variety of different transformations.

Sleep problems associated with long-term mortality in acute coronary syndrome: Effects of depression comorbidity and treatment

OBJECTIVES

The effects of sleep disturbance and its treatment on the prognosis of patients with acute coronary syndrome (ACS) are not well understood. This study investigated the impact of sleep disturbance on long-term all-cause mortality, according to depression comorbidity and treatment, in patients with ACS.

METHODS

A cross-sectional baseline study and a nested 24-week double-blind escitalopram-placebo controlled trial were carried out from May 2007 to March 2013; 5-12-year follow-up for all-cause mortality was conducted. A total of 1152 patients with ACS were stratified by baseline depression comorbidity and treatment allocation into four groups: no depression (N = 706), depression on escitalopram (N = 149), depression on placebo (N = 151), and depression on medical care as usual (CAU; N = 146). Sleep disturbance was evaluated by the Leeds Sleep Evaluation Questionnaire. During the 5-12-year follow-up, Kaplan-Meyer event rates for all-cause mortality were calculated; hazard ratios (HRs) using Cox regression models were estimated after adjustment for a range of covariates.

RESULTS

Worse sleep states at baseline increased long-term all-cause mortality in all patients (HRs 1.08-1.59). The associations between worse sleep states and long-term all-cause mortality were significant in patients without depression and in patients with depression who received CAU, but not in patients with depression who participated in the 24-week trial.

CONCLUSIONS

Routine evaluations of sleep disturbance in ACS and further treatment allocation may contribute to reducing long-term mortality associated with the disease.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier for the 24 week drug trial, NCT00419471.

Mediation effect of herpes zoster derived by statin use on cardiovascular disease risk

BACKGROUND/AIMS

Although statins are widely used to reduce the risk of cardiovascular disease (CVD) including stroke and myocardial infarction (MI), it is reported that statin use increases the incidence of herpes zoster (HZ) that is associated with increased risk of CVD. So, we evaluated the mediation effect of HZ caused by statin use on CVD.

METHODS

We analyzed a prospective cohort from the National Health Insurance Service-database of South Korea. All individuals received a medical check-up and were followed-up from 2002 to 2013.

RESULTS

A total of 275,382 individuals > 40 years old were followed up for 11 years from 2003. Of these, 11,415 people (4%) were classified as statin users and 263,967 (96%) as non-statin users. Those who used statins had significantly lower risks of cardiovascular events, stroke, and MI compared with non-statin users; the adjusted hazard ratios in the multivariate analysis were 0.90 (95% confidence interval [CI], 0.82 to 0.98), 0.88 (95% CI, 0.80 to 0.98), and 0.91 (95% CI, 0.79 to 1.07), respectively. When we calculated the mediating effect of cardiovascular events by statin use through HZ, 11.6% of the total beneficial effect of cardiovascular events by statin use was mitigated through the occurrence of HZ caused by statin use. This mediating effect was higher in the younger age group (< 60 years).

CONCLUSION

This study showed that statin use reduced CVD by 10%, but the protective effect of statin use against CVD was mitigated by approximately 10% through the development of HZ caused by statin use.

Efficacy and Safety of Cystatin C-Guided Renal Dose Adjustment of Cefepime Treatment in Hospitalized Patients with Pneumonia

Cystatin C (CysC) may estimate renal function more accurately than serum creatinine (SCr). The clinical impact of renal dose adjustment of cefepime according to CysC rather than SCr has remained uncertain. We investigated the efficacy and safety of CysC-guided cefepime dosing compared with SCr-guided dosing in hospitalized patients with pneumonia. All adults hospitalized with pneumonia between July 2016 and December 2018 who used cefepime for at least 3 days were enrolled. Mortality, acute kidney injury (AKI), cefepime-induced encephalopathy (CIE), and Clostridium difficile infection were compared between the CysC-guided and SCr-guided groups. One hundred and ninety patients were divided into two groups: 129 and 61 received cefepime based on CysC and SCr, respectively. In-hospital mortality did not significantly differ between the groups (12% versus 31%; hazard ratio (HR) 0.74; 95% confidence interval (CI), 0.31-1.77; p = 0.50). CysC-guided cefepime dosing decreased the risk of AKI (13% versus 61%; HR 0.18; 95% CI, 0.07-0.44; p < 0.001) and CIE (2% versus 11%; HR 0.11; 95% CI, 0.03-0.47; p = 0.003) compared with SCr-guided dosing. There was no significant difference in the risk of Clostridium difficile infection. CysC-guided dosing of cefepime was associated with decreased risk of the cefepime-associated morbidities including AKI and CIE without increasing mortality among the hospitalized patients with pneumonia.

Effectiveness of surgical, KF94, and N95 respirator masks in blocking SARS-CoV-2: a controlled comparison in 7 patients

BACKGROUND

Data on the filtration efficacies of various masks against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. We thus evaluate the effectiveness of the surgical mask, the N95 respirator mask, and its equivalent (KF94 mask) in filtering SARS-CoV-2.

METHODS

Patients hospitalised with SARS-CoV-2 infection were instructed to cough five times each while wearing (1) no mask, (2) surgical mask, (3) KF94 mask, and (4) N95 mask. The coughs were separated by 20-second intervals, and the patients were rested for at least 5 min between each setting. SARS-CoV-2 viral loads in patient samples (i.e. nasopharyngeal swabs and saliva), petri dishes placed in front of the patients during coughing, and swabs from the outer and inner surfaces of the masks were analysed with PCR.

RESULTS

A total of 7 patients with SARS-CoV-2 infection participated in the mask test. SARS-CoV-2 was detected on the petri dishes after coughing in 3 out of 7 cases with the surgical mask or no mask. Viral particles were not found in the petri dishes after coughing while wearing the N95 mask or the KF94 mask. While viral particles were detected in both the inner and outer surfaces of the surgical masks, those were detected only in the inner surfaces of the N95 and K94 masks.

CONCLUSION

Surgical masks were less effective in filtering viral particles from coughing patients with SARS-CoV-2 infection. N95 masks and its equivalents efficiently blocked SARS-CoV-2 particles from coughing patients.

Cross protection by inactivated recombinant influenza viruses containing chimeric hemagglutinin conjugates with a conserved neuraminidase or M2 ectodomain epitope

Influenza virus neuraminidase (NA) contains a universally conserved epitope (NAe, NA_222-230). However, no studies have reported vaccines targeting this NA conserved epitope and inducing antibodies recognizing NAe. The extracellular domain of M2 (M2e) is considered as an attractive target for a universal influenza vaccine. We generated recombinant influenza H1N1 viruses expressing conserved epitopes in hemagglutinin (HA) molecules: NAe (NAe-HA) or M2e (M2e-HA) within the HA head domain. Inactivated recombinant NAe-HA and M2e-HA viruses were more effective in inducing IgG antibodies specific for an inserted conserved epitope than live recombinant virus. Recombinant inactivated M2e-HA virus vaccination induced cross protection against H3N2 virus with less weight loss compared to NAe-HA and was more effective in inducing humoral and cellular M2e immune responses. This study provides insight into developing recombinant influenza virus vaccines compatible with current platforms to induce antibody responses to conserved poorly immunogenic epitopes.