Article
Microbiology
Irene Sanchez-Leon, Elena Perez-Nadales, Juan Antonio Marin-Sanz, Teresa Garcia-Martinez, Luis Martinez-Martinez
Summary: This study investigated heteroresistance in 10 wild-type Klebsiella pneumoniae isolates of clinical origin. The results showed the importance of persistent variants and stable mutants in heteroresistance, and described the genomic changes observed in mutants obtained in population analysis profiling (PAP) assays.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
Mudsser Azam, Rajni Gaind, Gulshan Yadav, Amit Sharma, Kirti Upmanyu, Manisha Jain, Ruchi Singh
Summary: The study investigated colistin resistance in Klebsiella pneumoniae, finding genetically distinct strains with various mechanisms of resistance indicating spontaneous emergence within this bacterial species.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Jungyu Seo, Yu Mi Wi, Jong Min Kim, Yae-Jean Kim, Kwan Soo Ko
Summary: This study revealed the common occurrence of colistin heteroresistance in KPC-2-producing Klebsiella pneumoniae isolates, which could lead to treatment failure. The presence of colistin-resistant subpopulations increased with exposure to colistin, indicating a potential evolution of resistance. Developing more reliable diagnostic methods is necessary to detect colistin heteroresistance and prevent treatment failures.
JOURNAL OF MICROBIOLOGY
(2021)
Article
Infectious Diseases
Irene Sanchez-Leon, Teresa Garcia-Martinez, Seydina M. Diene, Elena Perez-Nadales, Luis Martinez-Martinez, Jean-Marc Rolain
Summary: This study aimed to investigate heteroresistance in nine clinical isolates of Klebsiella pneumoniae producing OXA-48 and describe genomic changes in vitro. It was found that the heteroresistance in K. pneumoniae isolates was mainly attributed to insertions in the mgrB gene and point mutations in colistin resistance proteins. These findings contribute to the understanding of colistin resistance mechanisms in OXA-48-producing K. pneumoniae mutants.
Article
Infectious Diseases
Manuela Tietgen, Lisa Sedlaczek, Paul G. G. Higgins, Heike Kaspar, Christa Ewers, Stephan Goettig
Summary: This study explores common colistin resistance mechanisms in Klebsiella pneumoniae isolates from animals, finding that the resistance mechanisms were diverse alterations of MgrB in both human and animal isolates. Phylogenetic analysis indicated that colistin resistance mechanisms developed independently in human and animal isolates. Further analysis of resistance mechanisms is crucial due to the limited antibiotics available to treat infections with multidrug-resistant bacteria.
Article
Infectious Diseases
Tao Wang, Xiaojun Wang, Suming Chen, Jie Zhu, Zhichen Zhu, Fen Qu, Liang Chen, Hong Du
Summary: This study investigated the clinical emergence of colistin-heteroresistant, hypervirulent, and multidrug-resistant Klebsiella pneumoniae, and characterized the underlying molecular mechanisms. The results showed the detection of two colistin-heteroresistant isolates, which exhibited similar survival rates as the hypervirulent reference strain. Additionally, overexpression of efflux pump genes was involved in mediating colistin heteroresistance.
JOURNAL OF GLOBAL ANTIMICROBIAL RESISTANCE
(2023)
Article
Microbiology
Yifan Wang, Xinqian Ma, Lili Zhao, Yukun He, Wenyi Yu, Shining Fu, Wentao Ni, Zhancheng Gao
Summary: This study evaluated the prevalence of colistin heteroresistance in carbapenem-resistant Klebsiella pneumoniae (CR-KP) and investigated the mechanisms of colistin resistance and the effectiveness of combination therapies. The findings suggest that combination therapy can be used to treat infections caused by CR-KP with colistin heteroresistance.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Pushpa Kumari Nirwan, Nirupama Chatterjee, Rajesh Panwar, Mridu Dudeja, Namita Jaggi
Summary: This study investigated the molecular basis of colistin resistance in Klebsiella pneumoniae and its clonal transmission in a North Indian tertiary care hospital. Results indicated that colistin resistance was mainly attributed to mutations in PhoPQ and PmrAB TCS genes, with different sequence types sharing a common ancestor and showing clonal transmission patterns. These findings will contribute to the formulation of effective strategies for infection prevention and antimicrobial development.
JOURNAL OF ANTIBIOTICS
(2021)
Review
Biochemistry & Molecular Biology
Karolina Stojowska-Swedrzynska, Adrianna Lupkowska, Dorota Kuczynska-Wisnik, Ewa Laskowska
Summary: Klebsiella pneumoniae is a common pathogen responsible for various infections, and its multidrug resistance has been recognized as a significant public health threat. Heteroresistance, a frequent phenotype in pathogens, may be associated with an increased risk of recurrent infections and treatment failure in K. pneumoniae.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Microbiology
Yuesong Weng, Tao Wang, Bin Huang, Hua Yu, Wei Jia, Bin Shan, Fen Qu, Yiwei Tang, Liang Chen, Hong Du
Summary: This study investigated the extent of colistin heteroresistance among CRKP strains in China, revealing a prevalence of 6.2%. It was found that the ST11 clone accounted for 60.7% of the colistin-heteroresistant isolates. The study also showed that heteroresistance could be suppressed by an efflux pump inhibitor and identified the significant role of the PhoPQ pathway in the mechanisms of heteroresistance.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
Feiyang Zhang, Qin Li, Jiawei Bai, Manlin Ding, Xiangjin Yan, Guangxi Wang, Baoli Zhu, Yingshun Zhou
Summary: This study revealed that 8.39% of Klebsiella pneumoniae strains were amikacin-heteroresistant, with potential association with increased expression of aminoglycoside resistance genes. The majority of heteroresistant phenotypes were unstable, with partial or full reversion of minimal inhibitory concentrations to the level of susceptibility.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Joseph Meletiadis, Paschalis Paranos, Marilena Tsala, Spyros Pournaras, Sofia Vourli
Summary: This study found that high colistin exposures reduced high-level adaptive resistance at the expense of selection of heteroresistant subpopulations in an in vitro PK/PD model simulating clinical colistin exposures.
JOURNAL OF MEDICAL MICROBIOLOGY
(2022)
Article
Microbiology
Shota Fukuzawa, Toyotaka Sato, Kotaro Aoki, Soh Yamamoto, Noriko Ogasawara, Chie Nakajima, Yasuhiko Suzuki, Motohiro Horiuchi, Satoshi Takahashi, Shin-ichi Yokota
Summary: Integrated analysis of clinical isolates of E. cloacae complex revealed a significant prevalence (approximately 28%) of CST heteroresistance, which was accumulated in specific species and lineages. Heteroresistance occurred through upregulation of arnT mRNA induced by CST. Acquisition of mcr genes contributed less to CST resistance in ECC.
ANNALS OF CLINICAL MICROBIOLOGY AND ANTIMICROBIALS
(2023)
Article
Agriculture, Dairy & Animal Science
Zixuan Li, Li Xin, Chong Peng, Cong Liu, Peng Wang, Lanping Yu, Mengda Liu, Fangkun Wang
Summary: This study investigated the serotypes and antibiotic resistance profiles of Klebsiella pneumoniae isolated from broiler chickens on farms in Shandong Province, China. The results showed that these isolates exhibited resistance to multiple antibiotics, with a high carrying rate of beta-lactam resistance genes. Carbapenem-resistant and colistin-resistant K. pneumoniae were also detected in broiler chickens, indicating a potential threat to food safety and public health.
Article
Chemistry, Multidisciplinary
Yishuai Lin, Ying Zhang, Shixing Liu, Dandan Ye, Liqiong Chen, Na Huang, Weiliang Zeng, Wenli Liao, Yizhou Zhan, Tieli Zhou, Jianming Cao
Summary: Colistin, considered as a last resort treatment for Gram-negative bacteria infections, is becoming ineffective against colistin-resistant strains of Escherichia coli and Klebsiella Pneumoniae. The combination of quercetin with colistin efficiently eradicates colistin-resistant bacteria by downregulating resistance genes and enhancing bacterial cell membrane damage. This colistin/quercetin combination shows promise as an alternative pathway against colistin-resistant infections.
FRONTIERS IN CHEMISTRY
(2021)
Article
Surgery
Jinyoung Yang, Kyo Won Lee, Jin Yang Baek, Seongman Bae, Young Ho Lee, Haein Kim, Kyungmin Huh, Sun Young Cho, Cheol-In Kang, Doo Ryeon Chung, Kyong Ran Peck, Jae Berm Park, Sung -Han Kim, Tae -Jong Kim, Dong-Min Kim, Jae-Hoon Ko
Summary: Diminished immune response to COVID-19 vaccines is a concern for solid organ transplant recipients. A study investigated the immune responses of kidney transplant recipients after a third vaccine dose and breakthrough infection. The study found that the antibody titers and cellular immune responses were enhanced in recipients who experienced breakthrough infection.
AMERICAN JOURNAL OF TRANSPLANTATION
(2023)
Retraction
Microbiology
So Yeon Kim, Ji-Young Rhee, Kwan Soo Ko
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2023)
Retraction
Microbiology
Juyoun Shin, Jin Yang Baek, Sun Young Cho, Hee Jae Huh, Nam Yong Lee, Jae-Hoon Song, Doo Ryeon Chung, Kwan Soo Ko
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2023)
Article
Microbiology
Hyeri Seok, Ji-Young Choi, Michidmaral Ganbold, Jong Hyun Shin, Jooyun Kim, Won Suk Choi, Dae Won Park, Kwan Soo Ko
Summary: Recently, there has been an increase in the number of reported infections caused by non-diphtheriae Corynebacterium spp. in patients, as well as the discovery of novel species of Corynebacterium isolated from humans. We report two cases of human infections caused by Corynebacterium haemomassiliense-like organisms, which were initially unidentified by MALDI-TOF MS analysis. Further analysis using three housekeeping genes and phenotypic features revealed their close relation to the recently described species C. haemomassiliense. These strains were found to be multidrug-resistant but susceptible to vancomycin, meropenem, and linezolid. Our report suggests that these recently described Corynebacterium species may not be limited to a specific region, highlighting the difficulty in classifying the genus Corynebacterium.
CURRENT MICROBIOLOGY
(2023)
Article
Infectious Diseases
Jeongwoo Jo, Wonbeom Park, Dae-Hyuk Kweon, Kwan Soo Ko
Summary: Tigecycline heteroresistance is highly prevalent in Acinetobacter baumannii clinical isolates, reducing the efficacy of tigecycline treatment. This study confirmed the reproducibility and stability of mimicked tigecycline heteroresistance and found that the development of resistance in tigecycline-heteroresistant A. baumannii strains may depend on the selection of a pre-existing resistant subpopulation.
INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
(2023)
Article
Immunology
June -Young Koh, Jae-Hoon Ko, So Yun Lim, Seongman Bae, Kyungmin Huh, Sun Young Cho, Cheol-In Kang, Doo Ryeon Chung, Chi Ryang Chung, Sung -Han Kim, Kyong Ran Peck, Jeong Seok Lee
Summary: Triple immune modulator therapy in severe COVID-19 improves 30-day recovery by suppressing inflammation and regulating abnormal immune response.
CLINICAL IMMUNOLOGY
(2023)
Article
Microbiology
Sun Ju Kim, Jeongwoo Jo, Kwan Soo Ko
Summary: This study found that colistin resistance in K. variicola was mediated by the modification of lipid A. Although the isolate was obtained from faecal samples of healthy adults, colistin-resistant K. variicola challenges public health as an opportunistic pathogen.
JOURNAL OF MEDICAL MICROBIOLOGY
(2023)
Article
Infectious Diseases
Jin Yeong Hong, Cheol-In Kang, Jinyoung Yang, Jae-Hoon Ko, Kyungmin Huh, Sun Young Cho, Doo Ryeon Chung, Chul Won Jung, Kyong Ran Peck
Summary: Posaconazole delayed-release tablet prophylaxis is commonly used to prevent invasive fungal infection in acute myeloid leukemia patients undergoing chemotherapy. This study investigated breakthrough fungal infections in patients receiving posaconazole tablet prophylaxis, identifying risk factors and examining posaconazole profiles. Among the screened patients, breakthrough fungal infections occurred in 10 cases, leading to higher in-hospital mortality compared to non-infected patients. Risk factors for breakthrough fungal infection included prior hematopoietic stem cell transplantation, prolonged neutropenia, and low plasma posaconazole concentration. Therapeutic drug monitoring may be necessary for patients receiving posaconazole tablets.
Article
Immunology
Linda Shin, Jong Rim Choi, Kyungmin Huh, Doo Ryeon Chung, Sun Young Cho, Jongsuk Jeong, Jae-Hoon Ko, Cheol-In Kang, Kyong Ran Peck
Summary: The study aimed to assess the seroprevalence of measles and varicella zoster virus (VZV) among healthcare workers (HCW) and evaluate the concordance between self-reported history of previous disease or vaccination and seropositivity. A total of 10,278 HCWs underwent serologic tests for measles and 9,607 for VZV from 2017 to 2022. The overall seropositivity rates for measles and VZV were 78.1% and 92.8% respectively. Measles seropositivity declined gradually in HCWs born after 1985, while VZV seropositivity remained high in all birth cohorts. The self-reported vaccination history was not reliable for screening HCWs, with low negative predictive values.
Article
Multidisciplinary Sciences
Donggyun Ku, Gahyun Kim, Kyong Ran Peck, In Kwon Park, Rakwoo Chang, Donghan Kim, Seungjae Lee
Summary: Repeated vaccinations are necessary to achieve endemic phases, but individuals may hesitate to get vaccinated due to potential side effects. However, repeated vaccinations can lead to avoidance, impeding the establishment of endemic phases. Game theory and simulations show that a vaccination rate greater than 89% is required to achieve endemic phases.
SCIENTIFIC REPORTS
(2023)
Article
Immunology
Haein Kim, Young Rock Jang, Ji Yeon Lee, Jae-Hoon Ko, Jee Young Lee, Seongcheol Cho, Yong Dae Lee, Junghoon Song, Miri Hyun, Hyun Ah Kim, Soyoon Hwang, Sangmi Ryou, Yoo Jin Na, Joo-Yeon Lee, Changhee Lee, Nan Young Lee, Seunghwan Shin, Ki Tae Kwon, Jin Yong Kim, Kyong Ran Peck
Summary: A retrospective cohort study in South Korea assessed the clinical effectiveness of regdanvimab, an anti-SARS-CoV-2 monoclonal antibody, against emerging variants. The study found that regdanvimab effectively reduced progression to severe disease in the overall study population but showed limited effectiveness in patients with the Delta variant. The study highlights the need to evaluate increased dosage of monoclonal antibody agents for strains with reduced susceptibility.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2023)
Article
Infectious Diseases
Yun Young Cho, Kwan Soo Ko
Summary: This study investigated the impact of plasmids bearing carbapenemase genes on the formation of persister cells. Results showed that the ColE-type plasmid with blaOXA-232 significantly increased the formation of persister cells. Transformants with gene deletions showed decreased persister cell formation compared to transformants harboring intact pM5_OXA232. The expression levels of relA and spoT correlated with persister cell formation rates, especially against ciprofloxacin. This study highlights the influence of a small ColE-type plasmid bearing blaOXA-232 on persister cell formation.
JOURNAL OF GLOBAL ANTIMICROBIAL RESISTANCE
(2023)
Article
Infectious Diseases
Kyungmin Huh, Doo Ryeon Chung, Young Eun Ha, Jae-Hoon Ko, Hee Jae Huh, Nam Yong Lee, Sun Young Cho, Cheol-In Kang, Kyong Ran Peck, Jae-Hoon Song
Summary: This study aims to explore the reasons for the poor prognosis of patients with severe vancomycin-resistant enterococci (VRE) infection, whether it is due to vancomycin resistance or the predominance of Enterococcus faecium (Efm) among VRE. The study found that vancomycin resistance was independently associated with increased risk of mortality.
INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES
(2023)
Article
Infectious Diseases
Jeongwoo Jo, Ji Young Lee, Hongbaek Cho, Kwan Soo Ko
Summary: Recent studies have found that colistin dependence frequently occurs in colistin-susceptible Acinetobacter baumannii isolates. Although the parental strains are resistant, colistin-dependent mutants showed increased susceptibility to other antibiotics, suggesting the possibility of developing strategies to eliminate multidrug-resistant A. baumannii. Combination treatments of colistin with subinhibitory concentrations of other antibiotics, especially amikacin, inhibited the development of colistin dependence and eradicated the strains in in vitro assays.
MICROBIAL DRUG RESISTANCE
(2023)
Article
Medicine, General & Internal
Si -Ho Kim, Yu Mi Wi, Kyong Ran Peck
Summary: This study examined the clinical outcome of carbapenem-resistant Acinetobacter baumannii bacteremia and assessed the effectiveness of tetracyclines-based therapy. Among the 108 patients included in the study, the overall 30-day mortality rate was 71.4%. The Pitt's bacteremia score, colistin-single regimens, and tetracyclines single/tetracyclines-colistin combination regimens were found to be independently associated with 30-day mortality. The combination of tetracyclines and colistin showed a higher survival rate compared to tetracycline or colistin alone.
JOURNAL OF KOREAN MEDICAL SCIENCE
(2023)
