Journal of Microbiology

Minsang Shin

4 Articles

Lipocalin2 as a potential antibacterial drug against Acinetobacter baumannii infection: Daejin Lim , Su-Jin Park , Ha Young Kim , Minsang Shin , Miryoung Song; J. Microbiol. 2022;60(4):444-449. Published online March 28, 2022; DOI: https://doi.org/10.1007/s12275-022-2007-1

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Available antibiotics to treat Acinetobacter baumannii infection is limited due to increasing resistance and the emergence of multiple drug-resistant strains. Hence, discovering effective agents against A. baumannii to reduce the number of infectionrelated deaths is imperative. In search of novel and alternative antibiotics, the antibacterial function of lipocalin2 (Lcn2) was investigated to treat systemic infections of A. baumannii using a mouse neutropenia model. We observed a significant increase in serum Lcn2 levels upon bacterial injection into the mouse, and the administration of recombinant Lcn2 (rmLcn2) extended their survival. Such protective effects were also observed in rmLcn2-pretreated macrophages, where rmLcn2 reduced the survival of the pathogen inside the macrophages. The underlying molecular mechanism of Lcn2 protection was also investigated. We observed that pretreatment of the Raw- 264.7 macrophages with rmLcn2 markedly altered the expression of tonB3, which encodes a component of the transporter for ferrisiderophores in A. baumannii. However, the expression of katG, the gene encoding catalase, remained unaffected. These indicate that Lcn2-mediated defense against the pathogen is related to nutritional immunity rather than reactive oxygen species (ROS) production. Furthermore, the addition of rmLcn2 in infected mice diminished bacterial burden in multiple organs and enhanced the expression of tonB3 in the liver, spleen, and lungs of the infected mice. Increased survival rate due to rmLcn2 treatment declined when the infection model was established using lcn2-defective (lcn2-/-) mice, which indicated the necessity of endogenous Lcn2. Therefore, the antibacterial function of Lcn2 can be exploited to develop an alternative therapeutic agent against A. baumannii.

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Antimicrobial peptide thanatin fused endolysin PA90 (Tha-PA90) for the control of Acinetobacter baumannii infection in mouse model
Jeonghyun Lim, Heejoon Myung, Daejin Lim, Miryoung Song
Journal of Biomedical Science.2024;[Epub] CrossRef
Dynamic changes and clinical value of lipocalin 2 in liver diseases caused by microbial infections
Feng Chen, Shan-Shan Wu, Chao Chen, Cheng Zhou
World Journal of Hepatology.2024; 16(2): 177. CrossRef
Lipocalin-2 is an essential component of the innate immune response to Acinetobacter baumannii infection
Jessica R. Sheldon, Lauren E. Himmel, Dillon E. Kunkle, Andrew J. Monteith, K. Nichole Maloney, Eric P. Skaar, David S. Weiss
PLOS Pathogens.2022; 18(9): e1010809. CrossRef

Amino acid residues in the Ler protein critical for derepression of the LEE5 promoter in enteropathogenic E. coli: Su-Mi Choi , Jae-Ho Jeong , Hyon E. Choy , Minsang Shin; J. Microbiol. 2016;54(8):559-564. Published online August 2, 2016; DOI: https://doi.org/10.1007/s12275-016-6027-6

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Abstract

Enteropathogenic E. coli causes attaching and effacing (A/E) intestinal lesions. The genes involved in the formation of A/E lesions are encoded within a chromosomal island comprising of five major operons, LEE1-5. The global regulator H-NS represses the expression of these operons. Ler, a H-NS homologue, counteracts the H-NS–mediated repression. Using a novel genetic approach, we identified the amino acid residues in Ler that are involved in the interaction with H-NS: I20 and L23 in the C-terminal portion of α-helix 3, and I42 in the following unstructured linker region.

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Regulation of the Locus of Enterocyte Effacement in Attaching and Effacing Pathogens
R. Christopher D. Furniss, Abigail Clements, William Margolin
Journal of Bacteriology.2018;[Epub] CrossRef

Effect of promoter-upstream sequence on σ38-dependent stationary phase gene transcription: Hyung-Ju Lim , Kwangsoo Kim , Minsang Shin , Jae-Ho Jeong , Phil Youl Ryu , Hyon E. Choy; J. Microbiol. 2015;53(4):250-255. Published online April 8, 2015; DOI: https://doi.org/10.1007/s12275-015-4681-8

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Abstract

σ38 in Escherichia coli is required for expression of a subset of stationary phase genes. However, the promoter elements for σ38-dependent genes are virtually indistinguishable from that for σ70-dependent house-keeping genes. hdeABp is a σ38-dependent promoter and LEE5p is a σ70-dependent promoter, but both are repressed by H-NS, a bacterial histone- like protein, which acts at promoter upstream sequence. We swapped the promoter upstream sequences of the two promoters and found that the σ dependency was switched. This was further verified using lacUV5 core promoter. The
results
suggested that the determinant for σ38-dependent promoter lies in the promoter upstream sequence.

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Sequence-dependent model of genes with dual σ factor preference
Ines S.C. Baptista, Vinodh Kandavalli, Vatsala Chauhan, Mohamed N.M. Bahrudeen, Bilena L.B. Almeida, Cristina S.D. Palma, Suchintak Dash, Andre S. Ribeiro
Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms.2022; 1865(3): 194812. CrossRef
Function Enhancement of a Metabolic Module via Endogenous Promoter Replacement for Pseudomonas sp. JY-Q to Degrade Nicotine in Tobacco Waste Treatment
Jun Li, Fengmei Yi, Guoqing Chen, Fanda Pan, Yang Yang, Ming Shu, Zeyu Chen, Zeling Zhang, Xiaotong Mei, Weihong Zhong
Applied Biochemistry and Biotechnology.2021; 193(9): 2793. CrossRef
Recent advances in genetic engineering tools based on synthetic biology
Jun Ren, Jingyu Lee, Dokyun Na
Journal of Microbiology.2020; 58(1): 1. CrossRef

Note] Identification of High-Specificity H-NS Binding Site in LEE5 Promoter of Enteropathogenic Esherichia coli (EPEC): Abhay Prasad Bhat , Minsang Shin , Hyon E. Choy; J. Microbiol. 2014;52(7):626-629. Published online March 7, 2014; DOI: https://doi.org/10.1007/s12275-014-3562-x

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Abstract

Histone-like nucleoid structuring protein (H-NS) is a small but abundant protein present in enteric bacteria and is involved in compaction of the DNA and regulation of the transcription. Recent reports have suggested that H-NS binds to a specific AT rich DNA sequence than to intrinsically curved DNA in sequence independent manner. We detected two high-specificity H-NS binding sites in LEE5 promoter of EPEC centered at -110 and -138, which were close to the proposed consensus H-NS binding motif. To identify H-NS binding sequence in LEE5 promoter, we took a random mutagenesis approach and found the mutations at around -138 were specifically defective in the regulation byH-NS. It was concluded that H-NS exertsmaximumrepression via the specific sequence at around -138 and ubsequently contacts α subunit of RNAP through oligomerization.

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Horizontally Acquired Homologs of Xenogeneic Silencers: Modulators of Gene Expression Encoded by Plasmids, Phages and Genomic Islands
Alejandro Piña-Iturbe, Isidora D. Suazo, Guillermo Hoppe-Elsholz, Diego Ulloa-Allendes, Pablo A. González, Alexis M. Kalergis, Susan M. Bueno
Genes.2020; 11(2): 142. CrossRef
Recent advances in genetic engineering tools based on synthetic biology
Jun Ren, Jingyu Lee, Dokyun Na
Journal of Microbiology.2020; 58(1): 1. CrossRef
Regulation of the Locus of Enterocyte Effacement in Attaching and Effacing Pathogens
R. Christopher D. Furniss, Abigail Clements, William Margolin
Journal of Bacteriology.2018;[Epub] CrossRef
Bacterial-Chromatin Structural Proteins Regulate the Bimodal Expression of the Locus of Enterocyte Effacement (LEE) Pathogenicity Island in Enteropathogenic Escherichia coli
Hervé Leh, Ahmad Khodr, Marie-Christine Bouger, Bianca Sclavi, Sylvie Rimsky, Stéphanie Bury-Moné, Susan Gottesman
mBio.2017;[Epub] CrossRef
Alternative Synthesis Route of Biocompatible Polyvinylpyrrolidone Nanoparticles and Their Effect on Pathogenic Microorganisms
Vedran Milosavljevic, Pavlina Jelinkova, Ana Maria Jimenez Jimenez, Amitava Moulick, Yazan Haddad, Hana Buchtelova, Sona Krizkova, Zbynek Heger, Lukas Kalina, Lukas Richtera, Pavel Kopel, Vojtech Adam
Molecular Pharmaceutics.2017; 14(1): 221. CrossRef
H-NS and RNA polymerase: a love–hate relationship?
Robert Landick, Joseph T Wade, David C Grainger
Current Opinion in Microbiology.2015; 24: 53. CrossRef
Effect of promoter-upstream sequence on σ38-dependent stationary phase gene transcription
Hyung-Ju Lim, Kwangsoo Kim, Minsang Shin, Jae-Ho Jeong, Phil Youl Ryu, Hyon E. Choy
Journal of Microbiology.2015; 53(4): 250. CrossRef

Minsang Shin

2 Articles

Characterization of Newly Isolated Bacteriophages Targeting Carbapenem-Resistant Klebsiella pneumoniae: Bokyung Kim, Shukho Kim, Yoon-Jung Choi, Minsang Shin, Jungmin Kim; J. Microbiol. 2024;62(12):1133-1153. Published online December 10, 2024; DOI: https://doi.org/10.1007/s12275-024-00180-7

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Abstract: Klebsiella pneumoniae, a Gram-negative opportunistic pathogen, is increasingly resistant to carbapenems in clinical settings. This growing problem necessitates the development of alternative antibiotics, with phage therapy being one promising option. In this study, we investigated novel phages targeting carbapenem-resistant Klebsiella pneumoniae (CRKP) and evaluated their lytic capacity against clinical isolates of CRKP. First, 23 CRKP clinical isolates were characterized using Multi-Locus Sequence Typing (MLST), carbapenemase test, string test, and capsule typing. MLST classified the 23 K. pneumoniae isolates into 10 sequence types (STs), with the capsule types divided into nine known and one unknown type. From sewage samples collected from a tertiary hospital, 38 phages were isolated. Phenotypic and genotypic characterization of these phages was performed using Random Amplification of Polymorphic DNA-PCR (RAPD-PCR), transmission electron microscopy (TEM), and whole genome sequencing (WGS) analysis. Host spectrum analysis revealed that each phage selectively lysed strains sharing the same STs as their hosts, indicating ST-specific activity. These phages were subtyped based on their host spectrum and RAPD-PCR, identifying nine and five groups, respectively. Fourteen phages were selected for further analysis using TEM and WGS, revealing 13 Myoviruses and one Podovirus. Genomic analysis grouped the phages into three clusters: one closely related to Alcyoneusvirus, one to Autographiviridae, and others to Straboviridae. Our results showed that the host spectrum of K. pneumoniae-specific phages corresponds to the STs of the host strain. These 14 novel phages also hold promise as valuable resources for phage therapy against CRKP.

H-NS is a Transcriptional Repressor of the CRISPR-Cas System in Acinetobacter baumannii ATCC 19606: Kyeongmin Kim, Md Maidul Islam, Seunghyeok Bang, Jeongah Kim, Chung-Young Lee, Je Chul Lee, Minsang Shin; J. Microbiol. 2024;62(11):999-1012. Published online November 11, 2024; DOI: https://doi.org/10.1007/s12275-024-00182-5

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Abstract: Acinetobacter baumannii is a multidrug-resistant opportunistic pathogen primarily associated with hospital-acquired infections. The bacterium can gain multidrug resistance through several mechanisms, including horizontal gene transfer. A CRISPR-Cas system including several Cas genes could restrict the horizontal gene transfer. However, the molecular mechanism of CRISPR- Cas transcriptional regulation remains unclear. We identified a type I-F CRISPR-Cas system in A. baumannii ATCC 19606^T standard strain based on sequence analysis. We focused on the transcriptional regulation of Cas3, a key protein of the CRISPR-Cas system. We performed a DNA affinity chromatography-pulldown assay to identify transcriptional regulators of the Cas3 promoter. We identified several putative transcriptional factors, such as H-NS, integration host factor, and HU, that can bind to the promoter region of Cas3. We characterized AbH-NS using size exclusion chromatography and cross-linking experiments and demonstrated that the Cas3 promoter can be regulated by AbH-NS in a concentration-dependent manner via an in vitro transcription assay. CRISPR-Cas expression levels in wild-type and hns mutant strains in the early stationary phase were examined by qPCR and β-galactosidase assay. We found that H-NS can act as a repressor of Cas3. Our transformation efficiency results indicated that the hns mutation decreased the transformation efficiency, while the Cas3 mutation increased it. We report the existence and characterization of the CRISPR-Cas system in A. baumannii 19606^T and demonstrate that AbH-NS is a transcriptional repressor of CRISPR-Cas-related genes in A. baumannii.

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