Resilience of tigecycline heteroresistance phenotype in Acinetobacter baumannii.

Background: Heteroresistance, frequently observed in diverse bacterial species, imposes clinical challenges. For this study, we investigated the stability and resilience of tigecycline heteroresistance in Acinetobacter baumannii.

Methods: Four tigecycline-heteroresistant (HR) A.

Comparative genomic and phenotypic analysis of low- and high-virulent Acinetobacter baumannii strains: Insights into antimicrobial resistance and virulence potential.

Multi-drug resistant Acinetobacter baumannii poses a significant threat to public health. This study investigated the genomic features and phenotypic characteristics of two clinical A. baumannii strains, KBN10P01317 (low-virulent) and KBN10P01599 (high-virulent), which share the same sequence type and antimicrobial susceptibility profile.

Disease progression associated cytokines in COVID-19 patients with deteriorating and recovering health conditions.

Understanding the immune response to COVID-19 is challenging due to its high variability among individuals. To identify differentially expressed cytokines between the deteriorating and recovering phases, we analyzed the Electronic Health Records (EHR) and cytokine profile data in a COVID-19 cohort of 444 infected patients and 145 non-infected healthy individuals. We categorized each patient's progression into Deterioration Phase (DP) and Recovery Phase (RP) using longitudinal neutrophil, lymphocyte and lactate dehydrogenase levels.

Phylogenetic Analysis Based on Whole Genome Sequences, Antibiotic Resistance, and Virulence of Clinical Isolates from South Korea.

is a major cause of foodborne disease and frequently causes human salmonellosis in South Korea. In this study, we investigated the genome diversity, antimicrobial resistance, and virulence of clinical isolates of from South Korea. We collected 42 subsp.

Changes in the Distribution of Pathogens Causing Meningoencephalitis Before and During the COVID-19 Pandemic.

Background: Infectious meningoencephalitis (ME) is a major global health concern. Viruses are the most frequently implicated etiologies, whereas bacterial causes, although life-threatening, constitute a lesser proportion of ME cases, together with other pathogens. The strict implementation of COVID-19 mitigation measures led to the decreased viral and non-viral infectious diseases.

Overcoming the age-dependent SARS-CoV-2 vaccine response through hybrid immunity: analysis of humoral and cellular immunity with mass cytometry profiling.

Background: Age-dependent immune responses to coronavirus disease 2019 (COVID-19) vaccinations and breakthrough infections (BIs) in young and middle-aged individuals are unclear.

Methods: This nationwide multicenter prospective cohort study analyzed immune responses in participants of the ChAdOx1 (ChAd)-ChAd-mRNA vaccine group using cytometry by time-of-flight, anti-spike protein antibody (Sab) and anti-nucleocapsid antibody (Nab) titers, plaque reduction neutralization tests (PRNTs), and interferon-gamma (IFN-γ) release assays at various time points.

Results: We evaluated 347 participants with an average age of 38.

Clinical Outcomes of Solid Organ Transplant Recipients Hospitalized with COVID-19: A Propensity Score-Matched Cohort Study.

Background: Solid-organ transplant recipients (SOTRs) receiving immunosuppressive therapy are expected to have worse clinical outcomes from coronavirus disease 2019 (COVID-19). However, published studies have shown mixed results, depending on adjustment for important confounders such as age, variants, and vaccination status.

Materials And Methods: We retrospectively collected the data on 7,327 patients hospitalized with COVID-19 from two tertiary hospitals with government-designated COVID-19 regional centers.

Persistent differences in the immunogenicity of the two COVID-19 primary vaccines series, modulated by booster mRNA vaccination and breakthrough infection.

Introduction: The long-term impact of initial immunogenicity induced by different primary COVID-19 vaccine series remains unclear.

Methods: A prospective cohort study was conducted at 10 tertiary hospitals in Korea from March 2021 to September 2022. Immunogenicity assessments included anti-spike protein antibody (Sab), SARS-CoV-2-specific interferon-gamma releasing assay (IGRA), and multiplex cytokine assays for spike protein-stimulated plasma.

Principles and practices of antimicrobial stewardship programs in Korea.

This review addresses the escalating challenge posed by antibiotic resistance, highlighting its profound impact on global public health, including increased mortality rates and healthcare expenditures. The review focuses on the need to adopt the One Health approach to effectively manage antibiotic usage across human, animal, and environmental domains. Antimicrobial stewardship programs (ASPs) are considered as comprehensive strategies that encompass both core and supplementary initiatives aimed at enhancing prudent antibiotic use.

Antimicrobial Use and Carbapenem-Resistant Enterobacterales in Korea: A Nationwide Case-Control Study With Propensity Score Matching.

Background: Nationwide research on the association between carbapenem-resistant (CREs) and antibiotic use is limited.

Methods: This nested case-control study analyzed Korean National Health Insurance claims data from April 2017 to April 2019. Based on the occurrence of CRE, hospitalized patients aged ≥ 18 years were classified into CRE (cases) and control groups.

Effect of Regdanvimab on Mortality in Patients Infected with SARS-CoV-2 Delta Variants: A Propensity Score-Matched Cohort Study.

Introduction: Regdanvimab, a monoclonal antibody pharmaceutical, is the first Korean drug approved for treating coronavirus disease 2019 (COVID-19). We analyzed the therapeutic efficacy of regdanvimab in patients with the COVID-19 delta variant infection.

Methods: We retrospectively reviewed the electronic medical records of patients hospitalized at two Korean tertiary COVID-19 hospitals with COVID-19 delta variant infection between May 26, 2021, and January 30, 2022.

Clonal Distribution and Its Association With the Carbapenem Resistance Mechanisms of Carbapenem-Non-Susceptible Isolates From Korean Hospitals.

Background: Carbapenem resistance in is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible isolates from three Korean hospitals.

Methods: A total of 155 carbapenem-non-susceptible isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase.

Colistin heteroresistance in Citrobacter freundii clinical isolates from Republic of Korea.

We investigated colistin heteroresistance in Citrobacter freundii isolates from Korean hospitals. Using population analysis profiling (PAP), we detected colistin heteroresistance in 31.3% of isolates.

Clinical utility of quantitative immunoassays and surrogate virus neutralization tests for predicting neutralizing activity against the SARS-CoV-2 Omicron BA.1 and BA.5 variants.

Developing new antibody assays for emerging SARS-CoV-2 variants is challenging. SARS-CoV-2 surrogate virus neutralization tests (sVNT) targeting Omicron BA.1 and BA.

Conversion to colistin susceptibility by tigecycline exposure in colistin-resistant Klebsiella pneumoniae and its implications to combination therapy.

Objectives: This study investigated the effect of tigecycline exposure on susceptibility of colistin-resistant Klebsiella pneumoniae isolates to colistin and explored the possibility of antibiotic combination at low concentrations to treat colistin-resistant K. pneumoniae isolates.

Methods: Twelve tigecycline-resistant (TIR) mutants were induced in vitro from wild-type, colistin-resistant, and tigecycline-susceptible K.

Safety and Effectiveness of Regdanvimab for COVID-19 Treatment: A Phase 4 Post-marketing Surveillance Study Conducted in South Korea.

Introduction: Regdanvimab, a neutralising monoclonal antibody (mAb) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), received approval for the treatment of coronavirus disease 2019 (COVID-19) in South Korea in 2021. The Ministry of Food and Drug Safety in South Korea mandate that new medications be re-examined for safety and effectiveness post-approval in at least 3000 individuals. This post-marketing surveillance (PMS) study was used to evaluate the safety and effectiveness of regdanvimab in real-world clinical care.

Incidence and Distribution of the Pathogens Causing GI Infections at a University Hospital of Korea.

Background: Gastrointestinal (GI) infections, caused by various pathogens such as bacteria, viruses, protozoa, and parasites, are the second most common infectious diseases. Molecular diagnostics that can simultaneously detect these pathogens are commonly used in syndromic approaches. The authors aimed to identify the causative pathogens of GI infections to provide clinically useful information.

Analysis of microbiological tests in patients withholding or withdrawing life-sustaining treatment at the end stage of life in 2 Korean hospitals.

Objective: We evaluated the adequacy of microbiological tests in patients withholding or withdrawing life-sustaining treatment (WLST) at the end stage of life.

Setting: The study was conducted at 2 tertiary-care referral hospitals in Daegu, Republic of Korea.

Design: Retrospective cross-sectional study.

Immune Response Kinetics Following a Third Heterologous BNT162b2 Booster Dose After Primary 2-Dose ChAdOx1 Vaccination in Relation to Omicron Breakthrough Infection: A Prospective Nationwide Cohort Study in South Korea.

Background: Immune responses to each vaccine must be investigated to establish effective vaccination strategies for the ongoing coronavirus disease (COVID-19) pandemic. We investigated the long-term kinetics of immune responses after heterologous booster vaccination in relation to Omicron breakthrough infection (BI).

Methods: Our study included 373 healthcare workers who received primary ChAdOx1 vaccine doses and a third BNT162b2 vaccine dose.

Carbapenem Use in the Last Days of Life: A Nationwide Korean Study.

The appropriate use of carbapenem is a critical concern for patient safety and public health, and is a national priority. We investigated the nationwide status of carbapenem prescription in patients within their last 14 days of life to guide judicious-use protocols from the previous study comprised of 1350 decedents. Carbapenem use was universally controlled through computerised authorisation system at all centres during the study period.