Journal of Microbiology

Research Article

Transcriptomic insights into the effects of sublethal exposure to endolysin LNT113 on Escherichia coli: Heymin Song, Nanjoo Park, Eunsuk Kim, Seowon Jang, Sunghoon Kim, Jeongik Cho, Hyunjin Yoon; J. Microbiol. 2026;64(7):e2605009. Published online July 31, 2026; DOI: https://doi.org/10.71150/jm.2605009

41 View
4 Download

Abstract PDF Supplementary Material: The global rise of multidrug-resistant bacteria poses a critical threat to public health, and bacteriophage-derived endolysins have emerged as promising alternatives to conventional antibiotics. The engineered endolysin LNT113, derived from the Escherichia coli phage PBEC131 endolysin EC340, exhibits potent lytic activity against Gram-negative bacteria. This study investigated the transcriptomic responses of E. coli to sublethal LNT113 stress and identified genetic determinants required for bacterial adaptation to endolysin-induced stress. Transcriptomic analysis identified 552 differentially expressed genes (DEGs) following sublethal LNT113 exposure. Thirteen DEGs associated with stress response and envelope maintenance were individually deleted to generate thirteen mutant strains and to functionally evaluate their roles in bacterial stress tolerance. Among these, the ΔfabB and Δ(prmB–yfcL) mutants exhibited significantly reduced survival under sublethal LNT113 exposure, indicating increased susceptibility to the endolysin. Regarding the prmB–yfcL operon, individual genes were deleted to determine the gene critical for bacterial tolerance. Deletion of aroC and mepA rendered E. coli more susceptible to LNT113. Furthermore, 1-N-phenylnaphthylamine uptake assays demonstrated increased membrane permeability in the ΔfabB, ΔaroC, and ΔmepA mutants. Complementation with pWSK129::fabB, pWSK129::aroC, and pWSK129::mepA restored membrane integrity in the respective mutant strains. These findings suggest that fabB-mediated unsaturated fatty acid biosynthesis and mepA-dependent peptidoglycan remodeling are critical for maintaining envelope integrity under endolysin stress, whereas aroC may indirectly support bacterial tolerance to LNT113 via metabolic adaptation. This study provides insights into bacterial responses to LNT113 and offers a foundation for optimizing endolysin-based therapeutic strategies.

Article

Rapid determination of carbapenem resistance by low-cost colorimetric methods: Propidium Iodide and alamar blue staining: Jiyoon Choi , Jiwon Baek , Daehyuk Kweon , Kwan Soo Ko , Hyunjin Yoon; J. Microbiol. 2020;58(5):415-421. Published online March 28, 2020; DOI: https://doi.org/10.1007/s12275-020-9549-x

691 View
1 Download
5 Web of Science
5 Crossref

Carbapenems are a class of β-lactam antibiotics with a broad antimicrobial activity spectrum. Owing to their sturdy structures resistant to most β-lactamases, they have been regarded as one of the last-resort antibiotics for combating multidrugresistant bacterial infections. However, the emergence of carbapenem resistance increases predominantly in nosocomial pathogens. To prevent spread of carbapenem resistance in early stages, it is imperative to develop rapid diagnostic tests that will substantially reduce the time and cost in determining carbapenem resistance. Thus, we devised a staining-based diagnostic method applicable to three different Gram-negative pathogens of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae, all with the high potential to develop carbapenem resistance. Regardless of the resistance mechanisms presented by bacterial species and strains, double staining with propidium iodide (PI) and alamar blue (AB) identified resistant bacteria with an average sensitivity of 95.35%, 7 h after imipenem treatments in 343 clinical isolates. Among the three species tested, A. baumannii showed the highest diagnostic sensitivity of 98.46%. The PI and ABmediated staining method could be a promising diagnostic
method
with high-throughput efficacy and low cost.

Citations

Citations to this article as recorded by

Metabolic Hijacking by Engineered Probiotics Reprograms Tumor Metabolism and Immune Microenvironment for Self-Reinforcing Photodynamic Immunotherapy
Shurong Qin, Qi Wang, Zhuangwei Zhang, Junhui Gu, Guanzhong He, Fei Zeng, Ruiyue Chen, Bangshun He, Yuzhen Wang, Meng Wang, Yujun Song
Journal of the American Chemical Society.2025; 147(42): 38180. CrossRef
Cananga oil inhibits Salmonella infection by mediating the homeostasis of purine metabolism and the TCA cycle
Xinyu Yao, Jinying Gao, Lanqiao Wang, Xiaoning Hou, Litao Ge, Xinxin Qin, Jiazhang Qiu, Xuming Deng, Wei Li, Jianfeng Wang
Journal of Ethnopharmacology.2024; 325: 117864. CrossRef
Gold nanoparticle-DNA aptamer-assisted delivery of antimicrobial peptide effectively inhibits Acinetobacter baumannii infection in mice
Jaeyeong Park, Eunkyoung Shin, Ji-Hyun Yeom, Younkyung Choi, Minju Joo, Minho Lee, Je Hyeong Kim, Jeehyeon Bae, Kangseok Lee
Journal of Microbiology.2022; 60(1): 128. CrossRef
Rapid Determination of Antibiotic Resistance in Klebsiella pneumoniae by a Novel Antibiotic Susceptibility Testing Method Using SYBR Green I and Propidium Iodide Double Staining
Yabin Zhang, Weihua Fan, Chunhong Shao, Jiajia Wang, Yan Jin, Jing Shao, Ying Zhang, Yong Wang
Frontiers in Microbiology.2021;[Epub] CrossRef
Optical-Switch-Enabled Microfluidics for Sensitive Multichannel Colorimetric Analysis
Jiukai Tang, Xiaobao Cao, Guangyu Qiu, Andrew deMello, Jing Wang
Analytical Chemistry.2021; 93(17): 6784. CrossRef

Research Support, Non-U.S. Gov't

ppGpp-Mediated Stationary Phase Induction of the Genes Encoded by Horizontally Acquired Pathogenicity Islands and cob/pdu Locus in Salmonella enterica serovar Typhimurium: Miryoung Song , Hyun-Ju Kim , Sangryeol Ryu , Hyunjin Yoon , Jiae Yun , Hyon E. Choy; J. Microbiol. 2010;48(1):89-95. Published online March 11, 2010; DOI: https://doi.org/10.1007/s12275-009-0179-6

640 View
1 Download
12 Crossref

Abstract PDF

Salmonella enterica is highly diverse in terms of genome structure, which is at least partly due to the horizontal transfer of genetic elements from various sources. In this study, we examined the expression profiles of such genes in Salmonella Pathogenicity Islands (SPIs) and the cob/pdu locus, horizontally acquired large DNA segments, during growth under standard growth conditions. Transcripts from exponentially growing and early stationary phase Salmonellae were compared using various methods including cDNA microarray analysis. Nearly all genes encoded by SPIs and the cob/pdu locus were induced at the onset of the stationary phase in a stringent molecule ppGpp-dependent but stationary phase σ, σ38-independent manner. Although, it has been suggested that ppGpp acts in concert with DksA, we found the stationary phase induction of those SPI genes was not DksA dependent. It is suggested that ppGpp stimulates the expression of these stress-inducible genes encoded by horizontally acquired DNA, by itself or in concert with DksA.

Citations

Citations to this article as recorded by

DksA inhibitors against intracellular and persistent Salmonella are effective in acute models of infection
Ju-Sim Kim, Vijay Kumar, Lin Liu, Yu J. Choi, Simona Senovaityte, Bruce D. McCollister, Nathan Wlodarchak, David J. Orlicky, Peter J. Rice, Shaodong Dai, Michael F. Wempe, Andrés Vázquez-Torres
Science Advances.2026;[Epub] CrossRef
Intrinsic antimicrobial resistance: Molecular biomaterials to combat microbial biofilms and bacterial persisters
Swagatam Barman, Leman Buzoglu Kurnaz, Ryan Leighton, Md Waliullah Hossain, Alan W. Decho, Chuanbing Tang
Biomaterials.2024; 311: 122690. CrossRef
Innovative Approaches of Engineering Tumor-Targeting Bacteria with Different Therapeutic Payloads to Fight Cancer: A Smart Strategy of Disease Management
Khaled S Allemailem
International Journal of Nanomedicine.2021; Volume 16: 8159. CrossRef
Use of Salmonella Bacteria in Cancer Therapy: Direct, Drug Delivery and Combination Approaches
Fereshteh Badie, Maryam Ghandali, Seyed Alireza Tabatabaei, Mahmood Safari, Ahmad Khorshidi, Mohammad Shayestehpour, Maryam Mahjoubin-Tehran, Korosh Morshedi, Amin Jalili, Vida Tajiknia, Michael R. Hamblin, Hamed Mirzaei
Frontiers in Oncology.2021;[Epub] CrossRef
Guanosine tetraphosphate relieves the negative regulation of Salmonella pathogenicity island-2 gene transcription exerted by the AT-rich ssrA discriminator region
Timothy Tapscott, Ju-Sim Kim, Matthew A. Crawford, Liam Fitzsimmons, Lin Liu, Jessica Jones-Carson, Andrés Vázquez-Torres
Scientific Reports.2018;[Epub] CrossRef
Mechanisms of Bacterial Tolerance and Persistence in the Gastrointestinal and Respiratory Environments
R. Trastoy, T. Manso, L. Fernández-García, L. Blasco, A. Ambroa, M. L. Pérez del Molino, G. Bou, R. García-Contreras, T. K. Wood, M. Tomás
Clinical Microbiology Reviews.2018;[Epub] CrossRef
Cell mass-dependent expression of an anticancer protein drug by tumor-targeted Salmonella
Kwangsoo Kim, Sa-Young Min, Ho-Dong Lim, Sung-Hwan You, Daejin Lim, Jae-Ho Jeong, Hyun-Ju Kim, Joon Haeng Rhee, Kyeongil Park, Minsang Shin, Geun-Joong Kim, Jung-Joon Min, Hyon E. Choy
Oncotarget.2018; 9(9): 8548. CrossRef
Anti-tumor activity of an immunotoxin (TGFα-PE38) delivered by attenuated Salmonella typhimurium
Daejin Lim, Kwang Soo Kim, Hyun-Ju Kim, Kyong-Cheol Ko, Jae Jun Song, Jong Hyun Choi, Minsang Shin, Jung-Joon Min, Jae-Ho Jeong, Hyon E. Choy
Oncotarget.2017; 8(23): 37550. CrossRef
Transcriptional and Post-Transcriptional Modulation of SPI1 and SPI2 Expression by ppGpp, RpoS and DksA in Salmonella enterica sv Typhimurium
Christopher J. Rice, Vinoy K. Ramachandran, Neil Shearer, Arthur Thompson, Dipshikha Chakravortty
PLOS ONE.2015; 10(6): e0127523. CrossRef
The Primary Transcriptome of Salmonella enterica Serovar Typhimurium and Its Dependence on ppGpp during Late Stationary Phase
Vinoy K. Ramachandran, Neil Shearer, Arthur Thompson, Muna Anjum
PLoS ONE.2014; 9(3): e92690. CrossRef
A Novel Balanced-Lethal Host-Vector System Based on glmS
Kwangsoo Kim, Jae Ho Jeong, Daejin Lim, Yeongjin Hong, Misun Yun, Jung-Joon Min, Sahng-June Kwak, Hyon E. Choy, Hiroshi Shiku
PLoS ONE.2013; 8(3): e60511. CrossRef
Engineering and Visualization of Bacteria for Targeting Infarcted Myocardium
Uyenchi N Le, Hyung-Seok Kim, Jin-Sook Kwon, Mi Yeon Kim, Vu H Nguyen, Sheng Nan Jiang, Byeong-Il Lee, Yeongjin Hong, Myung Geun Shin, Joon Haeng Rhee, Hee-Seung Bom, Youngkeun Ahn, Sanjiv S Gambhir, Hyon E Choy, Jung-Joon Min
Molecular Therapy.2011; 19(5): 951. CrossRef

First
Prev
Page of 1
Next
Last

Search