Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.

Background: Haemophilus influenzae is the causative pathogen for various infectious diseases, such as respiratory infections, otitis media, sinusitis, and meningitis. This study aimed to investigate the prevalence and molecular characteristics of β-lactam resistance in non-typeable H. influenzae isolates in South Korea. Methods: In total, 115 non-duplicated H. influenzae isolates were included in this study.Bacterial identification and serotyping were performed using matrix assisted laser desorption ionization-time of flight mass spectrometry and polymerase chain reaction (PCR) of bexA, respectively. Antimicrobial susceptibility was tested using the broth microdilution method.The production of β-lactamase was determined using nitrocefin disks. The presence of blaTEM and blaROB was confirmed using PCR. ftsI was analyzed to identify amino acid mutations in penicillin-binding protein (PBP) 3. Results: Resistance rates to ampicillin, amoxicillin–clavulanate, and cefuroxime were 67.8%, 13.9%, and 32.2%, respectively. None of the isolates were resistant to cefotaxime or ceftriaxone. Among 78 ampicillin-resistant isolates, 71 were β-lactamase-producing ampicillinresistant (BLPAR), and 7 were β-lactamase-non-producing ampicillin-resistant. All BLPAR isolates carried blaTEM, and none carried blaROB. Among 16 amoxicillin–clavulanate-resistant isolates, 15 β-lactamase producers harbored blaTEM. Four to 7 PBP3 mutations per isolate were detected in all 16 non-β-lactamase-producing ampicillin-resistant or cephalosporinresistant isolates. Conclusion Beta-lactam resistance in non-typeable H. influenzae isolates is highly prevalent in South Korea, primarily because of blaTEM and various PBP3 mutations. Therefore, continuous monitoring of antimicrobial resistance rates and mechanisms in non-typeable H.influenzae is necessary.

During nationwide Fantimicrobial surveillance (Korea Global Antimicrobial Resistance Surveillance System [Kor-GLASS]), the recent emergence of non-oxacillinase (OXA)-23 production by carbapenem-resistant Acinetobacter baumannii (CRAB) isolates was noted. In this study, we evaluated resistance mechanisms other than OXA-23 production to elucidate the shift in considerable CRAB clones. The presence of OXA carbapenemase genes, such as blaOXA-23 , blaOXA-24 , blaOXA-58 , and blaOXA-51-ISAba1, was determined by PCR. Other carbapenemase genes, such as blaIMP , blaVIM , blaNDM , blaKPC , blaGES , and blaOXA-48 , were determined using sequencing. Strains lacking carbapenemase genes were subjected to whole genome sequencing, and resistance genes were analyzed using ResFinder. Four CRAB strains were collected through a Kor-GLASS study in 2022, in which OXA-23 production was not identified. The carbapenemase genotypes of the four CRAB strains lacking blaOXA-23 were blaOXA-51 -ISAba1, blaOXA-66/ACD25 , blaOXA-182, and blaNDM-1 . To the best of our knowledge, this is the first study to identify CRAB producing New Delhi metallo-β-lactamase (NDM)-1 in Korea. In conclusion, domestic CRAB resistance mechanisms may undergo subtle changes. Continuous observations are required to monitor the emergence of new clones.

Prosthodontic treatment is being performed for morphology and functional restoration due to damage and loss of teeth. As the aesthetic demands of patients increase, interest in ceramic materials with shades and translucency similar to natural teeth has increased.Recently, the manufacturing and processing technology of ceramic materials has greatly improved, and the market for dental ceramic materials is growing rapidly. The purpose of this literature review and evaluation is to provide information on the classification and properties of dental ceramic materials with excellent aesthetics and fracture resistance. In this article, it is classified as follows: I) Dental porcelain; II) Sinterable all-ceramic; III) Glass-ceramic for casting; IV) Glass-infiltrated alumina ceramic; V) Glass-ceramic ingots for heat-pressing technique; Vl) Blocks for CAD/CAM; Vll) Ceramic for CAD/3D printing. Dental ceramic materials and their restoration manufacturing methods have evolved significantly over the past decade. As a result, the manufacturing method of restorations has progressed from the layered firing technique of powdered materials or heat-pressing technique to the cutting and processing of single and multi-layer blocks using CAD/CAM technology, leading to the introduction of CAD/3D printing technology. In this manuscript, we will review the types of ceramic materials used in the fabrication of dental restorations and their advantages and disadvantages.

COVID-19 can lead to pulmonary complications, including organizing pneumonia.Steroids are essential in treating post-COVID-19 organizing pneumonia. However, research on the clinical benefits of initiating steroid treatment early for this condition is limited. To investigate the steroid initiation time in its association with treatment duration and corticosteroid dose for treating post-COVID-19 organizing pneumonia, we analyzed the data of 91 patients with post-COVID-19 organizing pneumonia at Chonnam National University Hospital between October 2020 and December 2022.Patients were categorized into early and late groups based on time from COVID-19 diagnosis to steroid initiation time for organizing pneumonia. The mean time interval between COVID-19 infection and steroid initiation time for treating organizing pneumonia, was 18.4±8.6 days. Within the early treatment group (treatment initiated ＜18.4 days after COVID-19), which included 55 patients, the mean duration of steroid treatment was 43.1±18.3days. In contrast, the late treatment group (initiated ≥18.4 days after COVID-19), which consisted of 36 patients, had a longer mean duration of steroid treatment 59.1±22.6 days) (p＜0.01). Regarding corticosteroid dosing, the early treatment group had an average dosage of 0.5±0.3 mg/kg/day, in contrast to the late group, which averaged 0.8±0.3 mg/kg/day (p＜0.01). Regression analysis showed steroid initiation time significantly influenced treatment duration (=0.80 , p＜0.01) and dosage (=0.03, p＜0.01). The clinical benefits of early steroid treatment for post-COVID-19 organizing pneumonia may lie in its association with reduced steroid treatment duration and dosage.

Treatment patterns and preferences for patients with Graves’ disease (GD) vary across countries. In this study, we assessed the initial therapies and subsequent treatment modalities employed for GD in real-world clinical practice in Korea. We analyzed 452,001 patients with GD from 2004 to 2020, obtained from the Korean National Health Insurance Service database. Initial treatments included antithyroid drug (ATD) therapy (98% of cases), thyroidectomy (1.3%), and radioactive iodine (RAI) therapy (0.7%). The rates of initial treatment failure were 58.5% for ATDs, 21.3% for RAI, and 2.1% for thyroidectomy. Even among cases of ATD treatment failure or recurrence, the rates of RAI therapy remained low. Regarding initial treatment, the 5-year remission rate was 46.8% among patients administered ATDs versus 91.0% among recipients of RAI therapy; at 10 years, these rates were 59.2% and 94.0%, respectively. Our findings highlight a marked disparity in the use of RAI therapy in Korea compared to Western countries. Further research is required to understand the reasons for these differences in treatment patterns.

Crohn’s disease (CD) is a relapsing and progressive condition characterized by diarrhea, abdominal pain, weight loss, and hematochezia that results in serious complications such as perforations, fistulas, and abscesses. Various medications, interventions, and surgical treatments have been used to treat CD. The Korean guidelines for CD management were distributed in 2012 and revised in 2017 by the Inflammatory Bowel Disease (IBD) Research Group of the Korean Association for the Study of Intestinal Diseases. Substantial progress in mucosal immunologic research has elucidated the pathophysiology of IBD, leading to development of biological agents for treatment of CD. The first developed biologic agent, tumor necrosis factor-α agents, were shown to be efficacious in CD, heralding a new era in management of CD. Subsequently, vedolizumab, a monoclonal antibody against integrin α4β7, and ustekinumab, a human monoclonal antibody that inhibits the common p40 subunit of interleukin-12 and interleukin-23, were both approved for clinical use and are efficacious and safe for both induction and maintenance of remission in moderate-to-severe CD patients. Moreover, a recent study showed the non-inferiority of CT-P13, an infliximab biosimilar, compared with infliximab in CD patients. The third Korean guidelines for CD management provide updated information regarding treatment of moderate-to-severe CD patients with biologic agents.

Purpose: Delirium in the intensive care unit (ICU) poses a significant safety and socioeconomic burden to patients and caregivers.However, invasive interventions for managing delirium have severe drawbacks. To reduce unnecessary interventions during ICU hospitalization, we aimed to investigate the features of delirium among ICU patients according to the occurrence of hypoactive symptoms, which are not expected to require invasive intervention. Materials and Methods: Psychiatrists assessed all patients with delirium in the ICU during hospitalization. Patients were grouped into two groups: a “non-hypoactive” group that experienced the non-hypoactive motor subtype once or more or a “hypoactive only” group that only experienced the hypoactive motor subtype. Clinical variables routinely gathered for clinical management were collected from electronic medical records. Group comparisons and logistic regression analyses were conducted. Results: The non-hypoactive group had longer and more severe delirium episodes than the hypoactive only group. Although the non-hypoactive group was prescribed more antipsychotics and required restraints longer, the hypoactive only group also received both interventions. In multivariable logistic regression analysis, BUN [odds ratio (OR): 0.993, pH OR: 0.202], sodium (OR: 1.022), RASS score (OR: 1.308) and whether restraints were applied [OR: 1.579 (95% confidence interval 1.194–2.089), p<0.001] were significant predictors of hypoactive only group classification. Conclusion Managing and predicting delirium patients based on whether patients experienced non-hypoactive delirium may be clinically important. Variables obtained during the initial 48 hours can be used to determine which patients are likely to require invasive interventions.

Background: Streptococcus pneumoniae is a serious pathogen causing various infections in humans. We evaluated the serotype distribution and antimicrobial resistance of S. pneumoniae causing invasive pneumococcal disease (IPD) after introduction of pneumococcal conjugate vaccine (PCV)13 in Korea and investigated the epidemiological characteristics of multidrug-resistant (MDR) isolates. Methods: S. pneumoniae isolates causing IPD were collected from 16 hospitals in Korea between 2017 and 2019. Serotyping was performed using modified sequential multiplex PCR and the Quellung reaction. Antimicrobial susceptibility tests were performed using the broth microdilution method. Multilocus sequence typing was performed on MDR isolates for epidemiological investigations. Results: Among the 411 S. pneumoniae isolates analyzed, the most prevalent serotype was 3 (12.2%), followed by 10A (9.5%), 34 (7.3%), 19A (6.8%), 23A (6.3%), 22F (6.1%), 35B (5.8%), 11A (5.1%), and others (40.9%). The coverage rates of PCV7, PCV10, PCV13, and pneumococcal polysaccharide vaccine (PPSV)23 were 7.8%, 7.8%, 28.7%, and 59.4%, respectively. Resistance rates to penicillin, ceftriaxone, erythromycin, and levofloxacin were 13.1%, 9.2%, 80.3%, and 4.1%, respectively. MDR isolates accounted for 23.4% of all isolates. Serotypes 23A, 11A, 19A, and 15B accounted for the highest proportions of total isolates at 18.8%, 16.7%, 14.6%, and 8.3%, respectively. Sequence type (ST)166 (43.8%) and ST320 (12.5%) were common among MDR isolates. Conclusions Non-PCV13 serotypes are increasing among invasive S. pneumoniae strains causing IPD. Differences in antimicrobial resistance were found according to the specific serotype. Continuous monitoring of serotypes and antimicrobial resistance is necessary for the appropriate management of S. pneumoniae infections.