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.Primary Cutaneous CD30+ Lymphoproliferative Disorders in South Korea: A Nationwide, Multi-Center, Retrospective, Clinical, and Prognostic Study
Woo Jin LEE ; Sook Jung YUN ; Joon Min JUNG ; Joo Yeon KO ; Kwang Ho KIM ; Dong Hyun KIM ; Myung Hwa KIM ; You Chan KIM ; Jung Eun KIM ; Chan-Ho NA ; Je-Ho MUN ; Jong Bin PARK ; Ji-Hye PARK ; Hai-Jin PARK ; Dong Hoon SHIN ; Jeonghyun SHIN ; Sang Ho OH ; Seok-Kweon YUN ; Dongyoun LEE ; Seok-Jong LEE ; Seung Ho LEE ; Young Bok LEE ; Soyun CHO ; Sooyeon CHOI ; Jae Eun CHOI ; Mi Woo LEE ; On behalf of The Korean Society of Dermatopathology
Annals of Dermatology 2025;37(2):75-85
Background:
Primary cutaneous CD30+ lymphoproliferative disorders (pcCD30-LPDs) are a diseases with various clinical and prognostic characteristics.
Objective:
Increasing our knowledge of the clinical characteristics of pcCD30-LPDs and identifying potential prognostic variables in an Asian population.
Methods:
Clinicopathological features and survival data of pcCD30-LPD cases obtained from 22 hospitals in South Korea were examined.
Results:
A total of 413 cases of pcCD30-LPDs (lymphomatoid papulosis [LYP], n=237; primary cutaneous anaplastic large cell lymphoma [C-ALCL], n=176) were included. Ninety percent of LYP patients and roughly 50% of C-ALCL patients presented with multiple skin lesions. Both LYP and C-ALCL affected the lower limbs most frequently. Multiplicity and advanced T stage of LYP lesions were associated with a chronic course longer than 6 months. Clinical morphology with patch lesions and elevated serum lactate dehydrogenase were significantly associated with LPDs during follow-up in LYP patients. Extracutaneous involvement of C-ALCL occurred in 13.2% of patients. Lesions larger than 5 cm and increased serum lactate dehydrogenase were associated with a poor prognosis in C-ALCL. The survival of patients with C-ALCL was unaffected by the anatomical locations of skin lesions or other pathological factors.
Conclusion
The multiplicity or size of skin lesions was associated with a chronic course of LYP and survival among patients with C-ALCL.
5.Independent and Combined Effects of Particulate Matter and Sleep Deprivation on Human Skin Barrier
Il Joo KWON ; Eun Jung LEE ; Jong Ho PARK ; Ji Young KIM ; Seohyun PARK ; Yu Jeong BAE ; Shinwon HWANG ; Hye-won NA ; Nari CHA ; Geunhyuk JANG ; Hyoung-June KIM ; Hae Kwang LEE ; Sang Ho OH
Annals of Dermatology 2025;37(3):131-139
Background:
The exposome encompasses all factors people encounter through life, with the skin constantly exposed. While particulate matter (PM) and sleep deprivation are known to contribute to barrier dysfunction, their combined effects remain unclear.
Objective:
To evaluate the independent and combined effects of PM exposure and short-term sleep deprivation on skin barrier function.
Methods:
Forty healthy Korean women (aged 24–58 years) were enrolled in this study. Forearms were divided into 4 sites: control, PM exposure, sleep deprivation, and PM plus sleep deprivation. Parameters such as trans-epidermal water loss (TEWL), hydration, elasticity, roughness, and redness were measured at baseline and post-exposure. RNA sequencing and reverse transcription-polymerase chain reaction were conducted on tape-stripped skin samples.
Results:
PM exposure significantly increased TEWL (+25.59%, p<0.01), roughness (+21.9%, p<0.01), and redness (+13.7%, p<0.0001) while reducing elasticity (−3.98%, p<0.01). Sleep deprivation modestly reduced elasticity (−1.39%, p<0.05) without affecting other parameters.Combined PM and sleep deprivation did not further exacerbate barrier dysfunction compared to PM alone. RNA sequencing revealed reduced FLG and LORICRIN expression and upregulated endoplasmic reticulum (ER) stress markers (HSP90B1, CANX) in both PM and sleep deprivation conditions.
Conclusion
PM exposure impaired skin barrier function, while short-term sleep deprivation alone did not significantly affect the barrier, either independently or in combination with PM.However, it was observed that the sleep deprivation-only, while not directly causing barrier damage, induced changes in ER stress-related gene expression in tape-stripped skin samples, like the PM exposure-only. This suggests that such signaling pathways could potentially exacerbate skin barrier deterioration.
6.Association Between Psychotic Symptoms of Mood Disorders and Hematologic Findings Related to Inflammation: A Retrospective Study
Yoon-Seok OH ; Woo-Young IM ; Sang-Ho SHIN ; Jae-Chang LEE ; Ji-Woong KIM ; Seung-Jun KIM ; Na-Hyun LEE ; Hong-Seok OH
Korean Journal of Psychosomatic Medicine 2024;32(2):77-86
Objectives:
:This study was aimed to determine whether the presence or absence of psychotic symptoms inmood disorders is statistically significantly related to the difference between NLR, MLR, PLR.
Methods:
:We retrospectively reviewed the medical records of 408 patients who were hospitalized with a diagnosis of bipolar disorder type 1 (BP-I) and major depressive disorder (MDD) and underwent complete blood count.Groups were divided based on the presence or absence of psychotic symptoms. The statistical significance of the differences in NLR, MLR, and PLR between each group was examined using t-test.
Results:
:When 382 mood disorder patients were divided into groups based solely on the presence or absence ofpsychotic symptoms, the difference between NLR and MLR was statistically significant (NLR: p=0.009, MLR:p=0.016). When dividing the mood disorder patients into subgroups of 176 BP-I patients and 206 MDD patients and using the same method for each subgroup, the tendency for higher NLR and MLR was maintained, but the sta-tistical significance disappeared.
Conclusions
:This study suggests the possibility of relationship between psychotic symptoms and NLR and MLR in mood disorders, but additional research appears to be necessary to clarify the possibility.
7.Risk Assessment of Metachronous Gastric Neoplasm after Endoscopic Resection for Early Gastric Cancer According to Age at Helicobacter pylori Eradication
Seunghan LEE ; Soo-Jeong CHO ; Hyunsoo CHUNG ; Bokyung KIM ; Mi Jin OH ; Yun Suk NA ; Jun Hee LEE ; Jiyoon KIM ; Sang Gyun KIM
Gut and Liver 2024;18(6):992-1001
Background/Aims:
Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication.
Methods:
Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years).
Results:
All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57).
Conclusions
The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.
8.Association Between Psychotic Symptoms of Mood Disorders and Hematologic Findings Related to Inflammation: A Retrospective Study
Yoon-Seok OH ; Woo-Young IM ; Sang-Ho SHIN ; Jae-Chang LEE ; Ji-Woong KIM ; Seung-Jun KIM ; Na-Hyun LEE ; Hong-Seok OH
Korean Journal of Psychosomatic Medicine 2024;32(2):77-86
Objectives:
:This study was aimed to determine whether the presence or absence of psychotic symptoms inmood disorders is statistically significantly related to the difference between NLR, MLR, PLR.
Methods:
:We retrospectively reviewed the medical records of 408 patients who were hospitalized with a diagnosis of bipolar disorder type 1 (BP-I) and major depressive disorder (MDD) and underwent complete blood count.Groups were divided based on the presence or absence of psychotic symptoms. The statistical significance of the differences in NLR, MLR, and PLR between each group was examined using t-test.
Results:
:When 382 mood disorder patients were divided into groups based solely on the presence or absence ofpsychotic symptoms, the difference between NLR and MLR was statistically significant (NLR: p=0.009, MLR:p=0.016). When dividing the mood disorder patients into subgroups of 176 BP-I patients and 206 MDD patients and using the same method for each subgroup, the tendency for higher NLR and MLR was maintained, but the sta-tistical significance disappeared.
Conclusions
:This study suggests the possibility of relationship between psychotic symptoms and NLR and MLR in mood disorders, but additional research appears to be necessary to clarify the possibility.
9.Risk Assessment of Metachronous Gastric Neoplasm after Endoscopic Resection for Early Gastric Cancer According to Age at Helicobacter pylori Eradication
Seunghan LEE ; Soo-Jeong CHO ; Hyunsoo CHUNG ; Bokyung KIM ; Mi Jin OH ; Yun Suk NA ; Jun Hee LEE ; Jiyoon KIM ; Sang Gyun KIM
Gut and Liver 2024;18(6):992-1001
Background/Aims:
Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication.
Methods:
Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years).
Results:
All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57).
Conclusions
The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.
10.Primary treatments for solitary hepatocellular carcinoma ≤ 3 cm: A systematic review and network meta-analysis
Sang-Hoon KIM ; Ki-Hun KIM ; Byeong-Gon NA ; Sung Min KIM ; Rak-Kyun OH
Annals of Hepato-Biliary-Pancreatic Surgery 2024;28(4):397-411
Various treatment modalities are available for small solitary hepatocellular carcinoma (HCC), yet the optimal primary treatment strategy for tumors ≤ 3 cm remains unclear. This network meta-analysis investigates the comparative efficacy of various interventions on the long-term outcomes of patients with solitary HCC ≤ 3 cm. A systematic search of electronic databases from January 2000 to December 2023 was conducted to identify studies that compared at least two of the following treatments: surgical resection (SR), radiofrequency ablation (RFA), microwave ablation (MWA), and transarterial chemoembolization (TACE). Survival data were extracted, and pooled hazard ratios with 95% confidence intervals were calculated using a frequentist network meta-analysis. A total of 30 studies, comprising 2 randomized controlled trials and 28 retrospective studies, involving 8,053 patients were analyzed. Surgical resection showed the highest overall survival benefit with a p-score of 0.95, followed by RFA at 0.59, MWA at 0.23, and TACE, also at 0.23. Moreover, SR provided the most significant recurrence-free survival advantage, with a p-score of 0.95, followed by RFA at 0.31 and MWA at 0.19. Sensitivity analyses, excluding low-quality or retrospective non-matched studies, corroborated these findings. This network meta-analysis demonstrates that SR is the most effective first-line curative treatment for single HCC ≤ 3 cm, followed by RFA in patients with preserved liver function. The limited data on MWA and TACE underscore the need for further studies.

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