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.Gender Difference of Moderated Mediating Effect of Grit Between Occupational Stress and Suicidal Ideation in Korean Workers
Sra JUNG ; Hyejeong JEON ; Mi Yeon LEE ; Eunsoo KIM ; Dong-Won SHIN ; Young-Chul SHIN ; Kang-Seob OH ; Min-Kyoung KIM ; Sang-Won JEON ; Sung Joon CHO
Journal of Korean Medical Science 2024;39(50):e308-
Background:
This study examined gender differences in occupational stress, depressive symptoms, and suicidal ideation by considering the potential moderating effect of grit on Korean employees.
Methods:
A total of 11,369 participants (7,735 men and 3,634 women) aged 19–65 years, employed across 18 private companies and local government organizations in Korea, completed questionnaires including the Short Grit Scale, Korean Occupational Stress Scale, and Center for Epidemiologic Studies Depression Scale between April 2020 and March 2022.Suicidal ideation was assessed based on its presence or absence. Mediation and moderation analyses were performed using the Statistical Package for the Social Sciences PROCESS macro.
Results:
Depressive symptoms partially mediated the relationship between occupational stress and suicidal ideation in male employees, whereas depressive symptoms fully mediated the relationship in female employees. Grit moderated the relationship between depressive symptoms and suicidal ideation in male employees but not in female employees.Furthermore, the moderated mediating effect of grit in male employees on the relationship between occupational stress and suicidal ideation provided less protection in cases of severe depression. The cross-sectional design does not allow for causal inferences.
Conclusion
These findings contribute to understanding of the gender differences in the impact of depressive symptoms on the relationship between occupational stress and suicidal ideation, as well as the protective effect of grit. These findings highlight the need for genderspecific approaches to prevent suicidal ideation among employees.
5.Gender Difference of Moderated Mediating Effect of Grit Between Occupational Stress and Suicidal Ideation in Korean Workers
Sra JUNG ; Hyejeong JEON ; Mi Yeon LEE ; Eunsoo KIM ; Dong-Won SHIN ; Young-Chul SHIN ; Kang-Seob OH ; Min-Kyoung KIM ; Sang-Won JEON ; Sung Joon CHO
Journal of Korean Medical Science 2024;39(50):e308-
Background:
This study examined gender differences in occupational stress, depressive symptoms, and suicidal ideation by considering the potential moderating effect of grit on Korean employees.
Methods:
A total of 11,369 participants (7,735 men and 3,634 women) aged 19–65 years, employed across 18 private companies and local government organizations in Korea, completed questionnaires including the Short Grit Scale, Korean Occupational Stress Scale, and Center for Epidemiologic Studies Depression Scale between April 2020 and March 2022.Suicidal ideation was assessed based on its presence or absence. Mediation and moderation analyses were performed using the Statistical Package for the Social Sciences PROCESS macro.
Results:
Depressive symptoms partially mediated the relationship between occupational stress and suicidal ideation in male employees, whereas depressive symptoms fully mediated the relationship in female employees. Grit moderated the relationship between depressive symptoms and suicidal ideation in male employees but not in female employees.Furthermore, the moderated mediating effect of grit in male employees on the relationship between occupational stress and suicidal ideation provided less protection in cases of severe depression. The cross-sectional design does not allow for causal inferences.
Conclusion
These findings contribute to understanding of the gender differences in the impact of depressive symptoms on the relationship between occupational stress and suicidal ideation, as well as the protective effect of grit. These findings highlight the need for genderspecific approaches to prevent suicidal ideation among employees.
6.Gender Difference of Moderated Mediating Effect of Grit Between Occupational Stress and Suicidal Ideation in Korean Workers
Sra JUNG ; Hyejeong JEON ; Mi Yeon LEE ; Eunsoo KIM ; Dong-Won SHIN ; Young-Chul SHIN ; Kang-Seob OH ; Min-Kyoung KIM ; Sang-Won JEON ; Sung Joon CHO
Journal of Korean Medical Science 2024;39(50):e308-
Background:
This study examined gender differences in occupational stress, depressive symptoms, and suicidal ideation by considering the potential moderating effect of grit on Korean employees.
Methods:
A total of 11,369 participants (7,735 men and 3,634 women) aged 19–65 years, employed across 18 private companies and local government organizations in Korea, completed questionnaires including the Short Grit Scale, Korean Occupational Stress Scale, and Center for Epidemiologic Studies Depression Scale between April 2020 and March 2022.Suicidal ideation was assessed based on its presence or absence. Mediation and moderation analyses were performed using the Statistical Package for the Social Sciences PROCESS macro.
Results:
Depressive symptoms partially mediated the relationship between occupational stress and suicidal ideation in male employees, whereas depressive symptoms fully mediated the relationship in female employees. Grit moderated the relationship between depressive symptoms and suicidal ideation in male employees but not in female employees.Furthermore, the moderated mediating effect of grit in male employees on the relationship between occupational stress and suicidal ideation provided less protection in cases of severe depression. The cross-sectional design does not allow for causal inferences.
Conclusion
These findings contribute to understanding of the gender differences in the impact of depressive symptoms on the relationship between occupational stress and suicidal ideation, as well as the protective effect of grit. These findings highlight the need for genderspecific approaches to prevent suicidal ideation among employees.
7.Gender Difference of Moderated Mediating Effect of Grit Between Occupational Stress and Suicidal Ideation in Korean Workers
Sra JUNG ; Hyejeong JEON ; Mi Yeon LEE ; Eunsoo KIM ; Dong-Won SHIN ; Young-Chul SHIN ; Kang-Seob OH ; Min-Kyoung KIM ; Sang-Won JEON ; Sung Joon CHO
Journal of Korean Medical Science 2024;39(50):e308-
Background:
This study examined gender differences in occupational stress, depressive symptoms, and suicidal ideation by considering the potential moderating effect of grit on Korean employees.
Methods:
A total of 11,369 participants (7,735 men and 3,634 women) aged 19–65 years, employed across 18 private companies and local government organizations in Korea, completed questionnaires including the Short Grit Scale, Korean Occupational Stress Scale, and Center for Epidemiologic Studies Depression Scale between April 2020 and March 2022.Suicidal ideation was assessed based on its presence or absence. Mediation and moderation analyses were performed using the Statistical Package for the Social Sciences PROCESS macro.
Results:
Depressive symptoms partially mediated the relationship between occupational stress and suicidal ideation in male employees, whereas depressive symptoms fully mediated the relationship in female employees. Grit moderated the relationship between depressive symptoms and suicidal ideation in male employees but not in female employees.Furthermore, the moderated mediating effect of grit in male employees on the relationship between occupational stress and suicidal ideation provided less protection in cases of severe depression. The cross-sectional design does not allow for causal inferences.
Conclusion
These findings contribute to understanding of the gender differences in the impact of depressive symptoms on the relationship between occupational stress and suicidal ideation, as well as the protective effect of grit. These findings highlight the need for genderspecific approaches to prevent suicidal ideation among employees.
8.Piperacillin-Tazobactam versus Cefotaxime as Empiric Treatment for Febrile Urinary Tract Infection in Hospitalized Children
Kyoung Hee HAN ; Min-su OH ; Jungmin AHN ; Juyeon LEE ; Youn Woo KIM ; Young Mi YOON ; Yoon-Joo KIM ; Hyun Sik KANG ; Ki-Soo KANG ; Larry A. GREENBAUM ; Jae Hong CHOI
Infection and Chemotherapy 2024;56(2):266-275
Background:
According to international pediatric urinary tract infection (UTI) guidelines, selecting ampicillin/ sulbactam or amoxicillin/clavulanate is recommended as the first-line treatment for pediatric UTI. In Korea, elevated resistance to ampicillin and ampicillin/sulbactam has resulted in the widespread use of third-generation cephalosporins for treating pediatric UTIs. This study aims to compare the efficacy of piperacillin-tazobactam (TZP) and cefotaxime (CTX) as first-line treatments in hospitalized children with UTIs.
Materials and Methods:
The study, conducted at Jeju National University Hospital, retrospectively analyzed medical records of children hospitalized for febrile UTIs between 2014 and 2017. UTI diagnosis included unexplained fever, abnormal urinalysis, and the presence of significant uropathogens. Treatment responses, recurrence, and antimicrobial susceptibility were assessed.
Results:
Out of 323 patients, 220 met the inclusion criteria. Demographics and clinical characteristics were similar between TZP and CTX groups. For children aged ≥3 months, no significant differences were found in treatment responses and recurrence. Extended-spectrum beta-lactamase (ESBL)-positive strains were associated with recurrence in those <3 months.
Conclusion
In Korea, escalating resistance to empirical antibiotics has led to the adoption of broad-spectrum empirical treatment. TZP emerged as a viable alternative to CTX for hospitalized children aged ≥3 months with UTIs.Consideration of ESBL-positive strains and individualized approaches for those <3 months are crucial.
9.Posterior Mediastinal Paraganglioma With SDHB Gene Mutation:Case Report
Do Won YOON ; Hong-Mi CHOI ; Kyoung-Ho SONG ; Jun Sung KIM ; Sung Hye KONG ; Dongkyu OH ; So Yeon PARK ; Eun Ju CHUN
Investigative Magnetic Resonance Imaging 2024;28(2):87-92
Paragangliomas, a term used for tumors of extra-adrenal origin, are chromaffin cell tumors that secrete catecholamines. Approximately one in three patients with paraganglioma has a gene mutation associated with familial paraganglioma syndromes (FPGLs), resulting from mutations in one of the subunits of the succinate dehydrogenase (SDH) gene. Most extraadrenal paragangliomas involve the head and neck, and only 2% of paragangliomas are found in the mediastinum. We report the case of a 37-year-old woman with a posterior mediastinal paraganglioma attached to the heart and recurrent glomus jugulare who underwent glomus tumor resection at the age of 17 years. Genetic testing revealed a mutation in the SDH subunit B gene associated with FPGL type 4 (FPGL4). This case report describes the features of multimodal imaging of a posterior mediastinal paraganglioma and explain how a multidisciplinary approach led to the diagnosis of FPGL4.
10.An Analysis of the Determinants of the Health-Related Quality of Life in Asian Patients With Cluster Headaches During Cluster Periods Using the Time Trade-Off Method
Soo-Kyoung KIM ; Min Kyung CHU ; Byung-Kun KIM ; Pil-Wook CHUNG ; Heui-Soo MOON ; Mi Ji LEE ; Yun-Ju CHOI ; Jeong Wook PARK ; Byung-Su KIM ; Tae-Jin SONG ; Kyungmi OH ; Jin-Young AHN ; Jong-Hee SOHN ; Kwang-Soo LEE ; Kwang-Yeol PARK ; Jae Myun CHUNG ; Chin-Sang CHUNG ; Soo-Jin CHO
Journal of Clinical Neurology 2024;20(1):86-93
Background:
and Purpose Patients with cluster headache (CH) exhibit impaired health-related quality of life (HRQoL). However, there have been few studies related to the HRQoL of patients with CH from Asian backgrounds. This study aimed to determine the impact of CH on HRQoL and to identify the factors affecting HRQoL in patients with CH during cluster periods.
Methods:
This prospective study enrolled patients with CH from 17 headache clinics in South Korea between September 2016 and February 2021. The study aimed to determine HRQoL in patients with CH using the EuroQol 5 Dimensions (EQ-5D) index and the time trade-off (TTO) method. Age- and sex-matched headache-free participants were recruited as a control group.
Results:
The study included 423 patients with CH who experienced a cluster period at the time. EQ-5D scores were lower in patients with CH (0.88±0.43, mean±standard deviation) than in the controls (0.99±0.33, p<0.001). The TTO method indicated that 58 (13.6%) patients with CH exhibited moderate-to-severe HRQoL deterioration. The HRQoL states in patients with CH were associated with current smoking patterns, headache severity, frequency, and duration, and scores on the Generalized Anxiety Disorder 7-item scale (GAD-7), Patient Health Questionnaire 9-item scale (PHQ-9), 6-item Headache Impact Test, and 12-item Allodynia Symptom Checklist. Multivariable logistic regression analyses demonstrated that the HRQoL states in patients with CH were negatively correlated with the daily frequency of headaches, cluster period duration, and GAD-7 and PHQ-9 scores.
Conclusions
Patients with CH experienced a worse quality of life during cluster periods compared with the headache-free controls, but the degree of HRQoL deterioration varied among them. The daily frequency of headaches, cluster period duration, anxiety, and depression were factors associated with HRQoL deterioration severity in patients with CH.

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