1.Minocycline Susceptibility of Carbapenem-Resistant Acinetobacter baumannii Blood Isolates from a Single Center in Korea: Role of tetB in Resistance
Taeeun KIM ; Eun Hee JEON ; Yoon-Kyoung HONG ; Jiwon JUNG ; Min Jae KIM ; Heungsup SUNG ; Mi-Na KIM ; Sung-Han KIM ; Sang-Ho CHOI ; Sang-Oh LEE ; Yang Soo KIM ; Yong Pil CHONG
Infection and Chemotherapy 2025;57(1):111-118
Background:
Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments. In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics. Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections. Nonsusceptibility to minocycline may occur through the efflux pump, TetB. The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs). We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes.
Materials and Methods:
Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L). Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes.
Results:
Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the PK-PD criteria. The minocycline minimum inhibitory concentration (MIC)50 /MIC90 was 1/8 mg/L. tetB was present in 49% of isolates and was associated with a higher minocycline MIC (MIC50/90 2/8 mg/L vs. 1/2 mg/L). No clear correlation was observed between tetB positivity and tigecycline MIC. Nine MLSTs were identified, with significant differences in tetB carriage rates between the major sequence types. Notably, ST191, associated with non-tetB carriage and greater susceptibility to minocycline, declined over the study period (P=0.004), while ST451, associated with tetB carriage, increased.
Conclusion
tetB was present in 49% of CRAB isolates and was associated with higher MICs and non-susceptibility by both CLSI and PK-PD criteria. However, absence of tetB was not a reliable predictor of minocycline PK-PD susceptibility. Additionally, shifts over time towards genotypes with reduced minocycline susceptibility were observed. Further research is needed to correlate these findings with clinical outcomes and identify additional resistance mechanisms.
2.Minocycline Susceptibility of Carbapenem-Resistant Acinetobacter baumannii Blood Isolates from a Single Center in Korea: Role of tetB in Resistance
Taeeun KIM ; Eun Hee JEON ; Yoon-Kyoung HONG ; Jiwon JUNG ; Min Jae KIM ; Heungsup SUNG ; Mi-Na KIM ; Sung-Han KIM ; Sang-Ho CHOI ; Sang-Oh LEE ; Yang Soo KIM ; Yong Pil CHONG
Infection and Chemotherapy 2025;57(1):111-118
Background:
Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments. In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics. Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections. Nonsusceptibility to minocycline may occur through the efflux pump, TetB. The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs). We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes.
Materials and Methods:
Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L). Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes.
Results:
Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the PK-PD criteria. The minocycline minimum inhibitory concentration (MIC)50 /MIC90 was 1/8 mg/L. tetB was present in 49% of isolates and was associated with a higher minocycline MIC (MIC50/90 2/8 mg/L vs. 1/2 mg/L). No clear correlation was observed between tetB positivity and tigecycline MIC. Nine MLSTs were identified, with significant differences in tetB carriage rates between the major sequence types. Notably, ST191, associated with non-tetB carriage and greater susceptibility to minocycline, declined over the study period (P=0.004), while ST451, associated with tetB carriage, increased.
Conclusion
tetB was present in 49% of CRAB isolates and was associated with higher MICs and non-susceptibility by both CLSI and PK-PD criteria. However, absence of tetB was not a reliable predictor of minocycline PK-PD susceptibility. Additionally, shifts over time towards genotypes with reduced minocycline susceptibility were observed. Further research is needed to correlate these findings with clinical outcomes and identify additional resistance mechanisms.
3.Minocycline Susceptibility of Carbapenem-Resistant Acinetobacter baumannii Blood Isolates from a Single Center in Korea: Role of tetB in Resistance
Taeeun KIM ; Eun Hee JEON ; Yoon-Kyoung HONG ; Jiwon JUNG ; Min Jae KIM ; Heungsup SUNG ; Mi-Na KIM ; Sung-Han KIM ; Sang-Ho CHOI ; Sang-Oh LEE ; Yang Soo KIM ; Yong Pil CHONG
Infection and Chemotherapy 2025;57(1):111-118
Background:
Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments. In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics. Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections. Nonsusceptibility to minocycline may occur through the efflux pump, TetB. The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs). We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes.
Materials and Methods:
Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L). Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes.
Results:
Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the PK-PD criteria. The minocycline minimum inhibitory concentration (MIC)50 /MIC90 was 1/8 mg/L. tetB was present in 49% of isolates and was associated with a higher minocycline MIC (MIC50/90 2/8 mg/L vs. 1/2 mg/L). No clear correlation was observed between tetB positivity and tigecycline MIC. Nine MLSTs were identified, with significant differences in tetB carriage rates between the major sequence types. Notably, ST191, associated with non-tetB carriage and greater susceptibility to minocycline, declined over the study period (P=0.004), while ST451, associated with tetB carriage, increased.
Conclusion
tetB was present in 49% of CRAB isolates and was associated with higher MICs and non-susceptibility by both CLSI and PK-PD criteria. However, absence of tetB was not a reliable predictor of minocycline PK-PD susceptibility. Additionally, shifts over time towards genotypes with reduced minocycline susceptibility were observed. Further research is needed to correlate these findings with clinical outcomes and identify additional resistance mechanisms.
4.Consensus-Based Guidelines for the Treatment of Atopic Dermatitis in Korea (Part II): Biologics and JAK inhibitors
Hyun-Chang KO ; Yu Ri WOO ; Joo Yeon KO ; Hye One KIM ; Chan Ho NA ; Youin BAE ; Young-Joon SEO ; Min Kyung SHIN ; Jiyoung AHN ; Bark-Lynn LEW ; Dong Hun LEE ; Sang Eun LEE ; Sul Hee LEE ; Yang Won LEE ; Ji Hyun LEE ; Yong Hyun JANG ; Jiehyun JEON ; Sun Young CHOI ; Ju Hee HAN ; Tae Young HAN ; Sang Wook SON ; Sang Hyun CHO
Annals of Dermatology 2025;37(4):216-227
Background:
Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed.
Objective:
This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based recommendations.
Methods:
The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved.
Results:
This guideline provides treatment guidance on advanced systemic treatment modalities for AD. In particular, the guideline offers up-to-date treatment recommendations for biologics and Janus-kinase inhibitors used in the treatment of patients with moderate to severe AD.It also provides guidance on other therapies for AD, along with tailored recommendations for children, adolescents, the elderly, and pregnant or breastfeeding women.
Conclusion
KADA’s updated AD treatment guidelines incorporate the latest evidence and expert opinion to provide a comprehensive approach to AD treatment. The guidelines will help clinicians optimize patient-specific therapies.
5.Consensus-Based Guidelines for the Treatment of Atopic Dermatitis in Korea (Part I): Basic Therapy, Topical Therapy, and Conventional Systemic Therapy
Hyun-Chang KO ; Yu Ri WOO ; Joo Yeon KO ; Hye One KIM ; Chan Ho NA ; Youin BAE ; Young-Joon SEO ; Min Kyung SHIN ; Jiyoung AHN ; Bark-Lynn LEW ; Dong Hun LEE ; Sang Eun LEE ; Sul Hee LEE ; Yang Won LEE ; Ji Hyun LEE ; Yong Hyun JANG ; Jiehyun JEON ; Sun Young CHOI ; Ju Hee HAN ; Tae Young HAN ; Sang Wook SON ; Sang Hyun CHO
Annals of Dermatology 2025;37(4):201-215
Background:
Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed.
Objective:
This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based practices.
Methods:
The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved.
Results:
The guidelines provide detailed recommendations on foundational therapies, including the use of moisturizers, cleansing and bathing practices, allergen avoidance, and patient education. Guidance on topical therapies, such as topical corticosteroids and calcineurin inhibitors, is also provided to help manage inflammation and maintain skin barrier function in patients with AD. Additionally, recommendations on conventional systemic therapies, including corticosteroids, cyclosporine, and methotrexate, are provided for managing moderate to severe AD.
Conclusion
KADA’s updated AD guidelines offer clinicians evidence-based strategies focused on basic therapies, topical therapies, and conventional systemic therapies, equipping them to enhance quality of care and improve patient outcomes in AD management.
6.2023 Consensus Korean Diagnostic Criteria for Atopic Dermatitis
Ji Hyun LEE ; Sul Hee LEE ; Youin BAE ; Young Bok LEE ; Yong Hyun JANG ; Jiyoung AHN ; Joo Yeon KO ; Hyun-Chang KO ; Hye One KIM ; Chan Ho NA ; Young-Joon SEO ; Min Kyung SHIN ; Yu Ri WOO ; Bark Lyn LEW ; Dong Hun LEE ; Sang Eun LEE ; Jiehyun JEON ; Sun Young CHOI ; Tae Young HAN ; Yang Won LEE ; Sang Wook SON ; Young Lip PARK
Annals of Dermatology 2025;37(1):12-21
Background:
In 2006, the Korean Atopic Dermatitis Association (KADA) working group released the diagnostic criteria for Korean atopic dermatitis (AD). Recently, more simplified, and practical AD diagnostic criteria have been proposed. Objective: Based on updated criteria and experience, we studied to develop and share a consensus on diagnostic criteria for AD in Koreans.
Materials and Methods:
For the diagnostic criteria, a questionnaire was constructed by searching the English-language literature in MEDLINE and the Cochrane Database of Systematic Reviews. A modified Delphi method composed of 3 rounds of email questionnaires was adopted for the consensus process. Fifty-four KADA council members participated in the 3 rounds of votes and expert consensus recommendations were established.
Results:
Diagnostic criteria for AD include pruritus, eczema with age-specific pattern, and chronic or relapsing history. Diagnostic aids for AD encompass xerosis, immunoglobulin E reactivity, hand–foot eczema, periorbital changes, periauricular changes, perioral changes, nipple eczema, perifollicular accentuation, and personal or family history of atopy.
Conclusion
This study streamlined and updated the diagnostic criteria for AD in Korea, making them more practicable for use in real-world clinical field.
7.Rationale, Design, and Interim Observations of the Steady Movement With Innovating Leadership for Heart Failure (SMILE HF) Registry: A Multicenter Prospective Cohort Registry for Patients With Acute Heart Failure
Jah Yeon CHOI ; Mi-Na KIM ; Seongwoo HAN ; Sunki LEE ; Myung Soo PARK ; Min Gyu KONG ; Sung-Hea KIM ; Yong-Hyun KIM ; Sang-Ho JO ; Sungeun KIM ; Seonghoon CHOI ; Jinsung JEON ; Jieun LEE ; Byambakhand BATTUMUR ; Seong-Mi PARK ; Eung Ju KIM ;
International Journal of Heart Failure 2024;6(3):129-136
Background and Objectives:
Heart failure (HF) is a leading cause of hospitalization and death worldwide. The Steady Movement with Innovating Leadership for Heart Failure (SMILE HF) aims to evaluate the clinical characteristics, management, hospital course, and long-term outcomes of patients hospitalized for acute HF in South Korea.
Methods:
This prospective, observational multicenter cohort study was conducted on consecutive patients hospitalized for acute HF in nine university hospitals since September 2019. Enrolment of 2000 patients should be completed in 2024, and follow-up is planned through 2025.
Results:
Interim analysis of 1,052 consecutive patients was performed to understand the baseline characteristics. The mean age was 69±15 years; 57.6% were male. The mean left ventricular ejection fraction was 39±15%. The prevalences of HF with reduced ejection fraction, HF with mildly reduced ejection fraction, and HF with preserved ejection fraction were 50.9%, 15.3%, and 29.2%. Ischemic cardiomyopathy (CMP) was the most common etiology (32%), followed by tachycardia-induced CMP (12.8%) and idiopathic dilated CMP (9.5%). The prescription rate of angiotensin-converting enzyme inhibitor/angiotensin receptor blockers/angiotensin receptor/ neprilysin inhibitor, beta-blockers, spironolactone, and sodium-glucose cotransporter-2 inhibitors at discharge were 76.8%, 66.5%, 50.0%, and 17.5%, respectively. The post-discharge 90-day mortality and readmission rates due to HF aggravation were 2.0% and 6.4%, respectively. Our analysis reveals the current state of acute HF in South Korea.
Conclusions
Our interim analysis provides valuable insights into the clinical characteristics, management, and early outcomes of acute HF patients in South Korea, highlighting the current state and treatment patterns in this population.
8.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Overview and Summary 2024
Young Joo PARK ; Eun Kyung LEE ; Young Shin SONG ; Bon Seok KOO ; Hyungju KWON ; Keunyoung KIM ; Mijin KIM ; Bo Hyun KIM ; Won Gu KIM ; Won Bae KIM ; Won Woong KIM ; Jung-Han KIM ; Hee Kyung KIM ; Hee Young NA ; Shin Je MOON ; Jung-Eun MOON ; Sohyun PARK ; Jun-Ook PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Dong Yeob SHIN ; Su-Jin SHIN ; Hwa Young AHN ; So Won OH ; Seung Hoon WOO ; Ho-Ryun WON ; Chang Hwan RYU ; Jee Hee YOON ; Ka Hee YI ; Min Kyoung LEE ; Sang-Woo LEE ; Seung Eun LEE ; Sihoon LEE ; Young Ah LEE ; Joon-Hyop LEE ; Ji Ye LEE ; Jieun LEE ; Cho Rok LEE ; Dong-Jun LIM ; Jae-Yol LIM ; Yun Kyung JEON ; Kyong Yeun JUNG ; Ari CHONG ; Yun Jae CHUNG ; Chan Kwon JUNG ; Kwanhoon JO ; Yoon Young CHO ; A Ram HONG ; Chae Moon HONG ; Ho-Cheol KANG ; Sun Wook KIM ; Woong Youn CHUNG ; Do Joon PARK ; Dong Gyu NA ;
International Journal of Thyroidology 2024;17(1):1-20
Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.
9.Clinical Characteristics of Hospitalized Patients Diagnosed with Scabies:A Retrospective Study
Young Chan KIM ; Han-Na KIM ; Been WOO ; Ko Eun KIM ; Yoo Sang BAEK ; Jiehyun JEON
Korean Journal of Dermatology 2024;62(4):218-227
Background:
Scabies, a common contagious skin disease caused by ectoparasites, is a significant public health concern in healthcare facilities, including tertiary hospitals.
Objective:
This study aimed to assess the clinical characteristics of hospitalized patients who were diagnosed with scabies. We focused on determining whether patient-related factors such as height, weight, underlying diseases, mobility, mental alertness, cognitive impairment, catheter insertion, and the presence of caregivers influenced the failure of the initial diagnosis or treatment.
Methods:
We retrospectively analyzed the medical records of 81 patients who were diagnosed with scabies during hospitalization between January 2011 and June 2023.
Results:
Of the 81 patients, 45 (55.6%) were male, with a mean age of 76.5 years. The most common primary diagnosis was an infectious disease (66.7%). The main suspected routes of infection were care facilities (63.5%) for patients who already had pruritic skin lesions before admission, and contact with caregivers (80.0%) for patients who developed new skin lesions after admission. The initial consultation failed to diagnose scabies in 19.8% of the patients, and among those, 62.5% had not undergone initial microscopic examination. Patients who were initially misdiagnosed had significantly longer hospitalizations and scabies treatment durations. Among the patients who underwent follow-up microscopic examination after the initial treatment, 60.0% showed positive results. Overall, 54.2% of the patients experienced initial treatment failure. Patient-related factors did not significantly differ between patients with and without initial diagnostic failure and between patients with and without initial treatment failure.
Conclusion
Dermatologists should consider performing microscopic examinations more frequently in hospitalized patients to improve diagnostic accuracy. Considering the high treatment failure rate, follow-up microscopic evaluation is recommended after initial treatment.
10.Assessment of Treatment Response in Patients With Severe Asthma Using Visual and Quantitative Analysis of Chest CT
Han Na LEE ; Jin AN ; Miji LEE ; Hye Jeon HWANG ; Jooae CHOE ; Jihye YOON ; Ji-Hyang LEE ; Min-Hye KIM ; Young-Joo CHO ; Sang Min LEE ; Tae-Bum KIM ; Joon Beom SEO
Korean Journal of Radiology 2024;25(7):673-683
Objective:
To evaluate the role of visual and quantitative chest CT parameters in assessing treatment response in patients with severe asthma.
Materials and Methods:
Korean participants enrolled in a prospective multicenter study, named the Precision Medicine Intervention in Severe Asthma study, from May 2020 to August 2021, underwent baseline and follow-up chest CT scans (inspiration/expiration) 10–12 months apart, before and after biologic treatment. Two radiologists scored bronchiectasis severity and mucus plugging extent. Quantitative parameters were obtained from each CT scan as follows: normal lung area (normal), air trapping without emphysema (AT without emph), air trapping with emphysema (AT with emph), and airway (total branch count, Pi10). Clinical parameters, including pulmonary function tests (forced expiratory volume in 1 s [FEV1] and FEV1/ forced vital capacity [FVC]), sputum and blood eosinophil count, were assessed at initial and follow-up stages. Changes in CT parameters were correlated with changes in clinical parameters using Pearson or Spearman correlation.
Results:
Thirty-four participants (female:male, 20:14; median age, 50.5 years) diagnosed with severe asthma from three centers were included. Changes in the bronchiectasis and mucus plugging extent scores were negatively correlated with changes in FEV1 and FEV1/FVC (ρ = from -0.544 to -0.368, all P < 0.05). Changes in quantitative CT parameters were correlated with changes in FEV1 (normal, r = 0.373 [P = 0.030], AT without emph, r = -0.351 [P = 0.042]), FEV1/FVC (normal, r = 0.390 [P = 0.022], AT without emph, r = -0.370 [P = 0.031]). Changes in total branch count were positively correlated with changes in FEV1 (r = 0.349 [P = 0.043]). There was no correlation between changes in Pi10 and the clinical parameters (P > 0.05).
Conclusion
Visual and quantitative CT parameters of normal, AT without emph, and total branch count may be effective for evaluating treatment response in patients with severe asthma.

Result Analysis
Print
Save
E-mail