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Snoeck S, Guidi C, De Mey M. "Metabolic burden" explained: stress symptoms and its related responses induced by (over)expression of (heterologous) proteins in Escherichia coli. Microb Cell Fact 2024; 23:96. [PMID: 38555441 PMCID: PMC10981312 DOI: 10.1186/s12934-024-02370-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/18/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Engineering bacterial strains to redirect the metabolism towards the production of a specific product has enabled the development of industrial biotechnology. However, rewiring the metabolism can have severe implications for a microorganism, rendering cells with stress symptoms such as a decreased growth rate, impaired protein synthesis, genetic instability and an aberrant cell size. On an industrial scale, this is reflected in processes that are not economically viable. MAIN TEXT In literature, most stress symptoms are attributed to "metabolic burden", however the actual triggers and stress mechanisms involved are poorly understood. Therefore, in this literature review, we aimed to get a better insight in how metabolic engineering affects Escherichia coli and link the observed stress symptoms to its cause. Understanding the possible implications that chosen engineering strategies have, will help to guide the reader towards optimising the envisioned process more efficiently. CONCLUSION This review addresses the gap in literature and discusses the triggers and effects of stress mechanisms that can be activated when (over)expressing (heterologous) proteins in Escherichia coli. It uncovers that the activation of the different stress mechanisms is complex and that many are interconnected. The reader is shown that care has to be taken when (over)expressing (heterologous) proteins as the cell's metabolism is tightly regulated.
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Affiliation(s)
- Sofie Snoeck
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium
| | - Chiara Guidi
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium
| | - Marjan De Mey
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium.
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2
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Buzun E, Hsu CY, Sejane K, Oles RE, Vasquez Ayala A, Loomis LR, Zhao J, Rossitto LA, McGrosso DM, Gonzalez DJ, Bode L, Chu H. A bacterial sialidase mediates early-life colonization by a pioneering gut commensal. Cell Host Microbe 2024; 32:181-190.e9. [PMID: 38228143 PMCID: PMC10922750 DOI: 10.1016/j.chom.2023.12.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/14/2023] [Accepted: 12/19/2023] [Indexed: 01/18/2024]
Abstract
The early microbial colonization of the gastrointestinal tract can have long-term impacts on development and health. Keystone species, including Bacteroides spp., are prominent in early life and play crucial roles in maintaining the structure of the intestinal ecosystem. However, the process by which a resilient community is curated during early life remains inadequately understood. Here, we show that a single sialidase, NanH, in Bacteroides fragilis mediates stable occupancy of the intestinal mucosa in early life and regulates a commensal colonization program. This program is triggered by sialylated glycans, including those found in human milk oligosaccharides and intestinal mucus. NanH is required for vertical transmission from dams to pups and promotes B. fragilis dominance during early life. Furthermore, NanH facilitates commensal resilience and recovery after antibiotic treatment in a defined microbial community. Collectively, our study reveals a co-evolutionary mechanism between the host and microbiota mediated through host-derived glycans to promote stable colonization.
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Affiliation(s)
- Ekaterina Buzun
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chia-Yun Hsu
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kristija Sejane
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Renee E Oles
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Adriana Vasquez Ayala
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Luke R Loomis
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jiaqi Zhao
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Leigh-Ana Rossitto
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dominic M McGrosso
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - David J Gonzalez
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lars Bode
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Larsson-Rosenquist Foundation Mother-Milk-Infant Center of Research Excellence (MOMI CORE), University of California, San Diego, La Jolla, CA 92093, USA; Human Milk Institute (HMI), University of California, San Diego, La Jolla, CA 92093, USA
| | - Hiutung Chu
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA; Human Milk Institute (HMI), University of California, San Diego, La Jolla, CA 92093, USA; Chiba University-UC San Diego Center for Mucosal Immunology, Allergy and Vaccines (cMAV), University of California, San Diego, La Jolla, CA 92093, USA; Humans and the Microbiome Program, Canadian Institute for Advanced Research, Toronto, ON M5G 1M1, Canada.
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3
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Ren W, Feng Y. Persistence of human- and cattle-associated Bacteroidales and mitochondrial DNA markers in freshwater mesocosms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165742. [PMID: 37487899 DOI: 10.1016/j.scitotenv.2023.165742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/05/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023]
Abstract
Accurate identification of the origins of non-point source pollution is essential for the effective control of fecal pollution. Host-associated Bacteroidales and mitochondrial DNA (mtDNA) markers have been developed to identify the sources of human and cattle fecal pollution. However, the differences in persistence between these two types of markers under different environmental conditions are still poorly understood. Here, we conducted mesocosm experiments to investigate the influence of indigenous microbiota and nutrients on the decay of Bacteroidales and mtDNA markers associated with humans and cattle. Raw sewage or cattle feces were inoculated into mesocosms containing natural eutrophic water, sterile eutrophic water or artificial freshwater. The Bacteroidales markers HF183 (human) and CowM3 (cattle) and mtDNA markers HcytB (human) and QMIBo (cattle) were quantified using the quantitative polymerase chain reaction (qPCR) assays. All markers but HF183 decreased the fastest in the presence of indigenous microbiota. Nutrients caused a decrease in the persistence of HF183; however, no significant nutrient effects were observed for HcytB, CowM3, and QMIBo. The time to reach one log reduction (T90) for HF183 and HcytB was similar; CowM3 reached T90 earlier than QMIBo in all the treatments but eutrophic water. E. coli persisted longer than both Bacteroidales and mtDNA markers in the mesocosms regardless of inoculum type. Additionally, 16S rRNA gene amplicon sequencing was used to determine the changes in bacterial communities accompanying the marker decay. Analysis using the SourceTracker software showed that bacterial communities in the mesocosms became more dissimilar to those in the corresponding inoculants over time. Our results indicate that environmental factors are important determinants of genetic markers' persistence, but their impact can vary depending on the genetic markers. The cattle Bacteroidales markers may be more suitable for determining recent fecal contamination than cattle mtDNA.
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Affiliation(s)
- Wenjing Ren
- Department of Crop, Soil and Environmental Sciences, Auburn University, Auburn, AL 36849, USA
| | - Yucheng Feng
- Department of Crop, Soil and Environmental Sciences, Auburn University, Auburn, AL 36849, USA.
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4
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Davati N, Ghorbani A, Ashrafi-Dehkordi E, P. Karbanowicz T. Gene Networks Analysis of Salmonella Typhimurium Reveals New Insights on Key Genes Involved in Response to Low Water Activity. IRANIAN JOURNAL OF BIOTECHNOLOGY 2023; 21:e3640. [PMID: 38269200 PMCID: PMC10804061 DOI: 10.30498/ijb.2023.387696.3640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/29/2023] [Indexed: 01/26/2024]
Abstract
Background When Salmonella enterica serovar Typhimurium, a foodborne bacterium, is exposed to osmotic stress, cellular adaptations increase virulence severity and cellular survival. Objectives The aim of the gene network analysis of S. Typhimurium was to provide insights into the various interactions between the genes involved in cellular survival under low water activity (aw). Materials and Methods We performed a gene network analysis to identify the gene clusters and hub genes of S. Typhimurium using Cytoscape in three food samples subjected to aw stress after 72 hours. Results The identified hub genes of S. Typhimurium belonged to down-regulated genes and were related to translation, transcription, and ribosome structure in the food samples. The rpsB and Tig were identified as the most important of the hub genes. Enrichment analysis of the hub genes also revealed the importance of translation and cellular protein metabolic processes. Moreover, the biological process associated with organonitrogen metabolism in milk chocolate was identified. According to the KEGG pathway results of gene cluster analysis, cellular responses to stress were associated with RNA polymerase, ribosome, and oxidative phosphorylation. Genes encoding RNA polymerase activity, including rpoA, rpoB, and rpoZ, were also significantly identified in the KEGG pathways. The identified motifs of hub DEGs included EXPREG_00000850, EXPREG_00000b00, EXPREG_000008e0, and EXPREG_00000850. Conclusion Based on the results of the gene network analysis, the identified hub genes may contribute to adaptation to food compositions and be responsible for the development of low water stress tolerance in Salmonella. Among the food samples, the milk chocolate matrix leads to more adaptation pathways for S. Typhimurium survival, as more hub genes were down-regulated and more motifs were detected. The identified motifs were involved in carbohydrate metabolism, carbohydrate transport, electron transfer, and oxygen transfer.
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Affiliation(s)
- Nafiseh Davati
- Department of Food Science and Technology, College of Food Industry, Bu-Ali Sina University, Hamedan, Iran
| | - Abozar Ghorbani
- Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute (NSTRI), Karaj, Iran
| | - Elham Ashrafi-Dehkordi
- Nutrition Research Center, Department of Food Hygiene and Quality Control, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
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5
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Buzun E, Hsu CY, Sejane K, Oles RE, Ayala AV, Loomis LR, Zhao J, Rossitto LA, McGrosso D, Gonzalez DJ, Bode L, Chu H. A bacterial sialidase mediates early life colonization by a pioneering gut commensal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552477. [PMID: 37609270 PMCID: PMC10441351 DOI: 10.1101/2023.08.08.552477] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The early microbial colonization of the gastrointestinal tract can lead to long-term impacts in development and overall human health. Keystone species, including Bacteroides spp ., play a crucial role in maintaining the structure, diversity, and function of the intestinal ecosystem. However, the process by which a defined and resilient community is curated and maintained during early life remains inadequately understood. Here, we show that a single sialidase, NanH, in Bacteroides fragilis mediates stable occupancy of the intestinal mucosa and regulates the commensal colonization program during the first weeks of life. This program is triggered by sialylated glycans, including those found in human milk oligosaccharides and intestinal mucus. After examining the dynamics between pioneer gut Bacteroides species in the murine gut, we discovered that NanH enables vertical transmission from dams to pups and promotes B. fragilis dominance during early life. Furthermore, we demonstrate that NanH facilitates commensal resilience and recovery after antibiotic treatment in a defined microbial community. Collectively, our study reveals a co-evolutionary mechanism between the host and the microbiota mediated through host-derived glycans to promote stable intestinal colonization.
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6
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Takano S, Takahashi H, Yama Y, Miyazaki R, Furusawa C, Tsuru S. Inference of transcriptome signatures of Escherichia coli in long-term stationary phase. Sci Rep 2023; 13:5647. [PMID: 37024648 PMCID: PMC10079935 DOI: 10.1038/s41598-023-32525-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023] Open
Abstract
"Non-growing" is a dominant life form of microorganisms in nature, where available nutrients and resources are limited. In laboratory culture systems, Escherichia coli can survive for years under starvation, denoted as long-term stationary phase, where a small fraction of cells manages to survive by recycling resources released from nonviable cells. Although the physiology by which viable cells in long-term stationary phase adapt to prolonged starvation is of great interest, their genome-wide response has not been fully understood. In this study, we analyzed transcriptional profiles of cells exposed to the supernatant of 30-day long-term stationary phase culture and found that their transcriptome profiles displayed several similar responses to those of cells in the 16-h short-term stationary phase. Nevertheless, our results revealed that cells in long-term stationary phase supernatant exhibit higher expressions of stress-response genes such as phage shock proteins (psp), and lower expressions of growth-related genes such as ribosomal proteins than those in the short-term stationary phase. We confirmed that the mutant lacking the psp operon showed lower survival and growth rate in the long-term stationary phase culture. This study identified transcriptional responses for stress-resistant physiology in the long-term stationary phase environment.
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Affiliation(s)
- Sotaro Takano
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
- International Center for Materials Nanoarchitectonics (NIMS), Research Center for Macromolecules and Biomaterials, Tsukuba, Japan
| | - Hiromi Takahashi
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Yoshie Yama
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka, Japan
| | - Ryo Miyazaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
- Computational Bio Big Data Open Innovation Laboratory (CBBD-OIL), AIST, Tokyo, Japan
| | - Chikara Furusawa
- Graduate School of Science, Universal Biology Institute, The University of Tokyo, Tokyo, Japan
- Center for Biosystem Dynamics Research, RIKEN, Kobe, Japan
| | - Saburo Tsuru
- Graduate School of Science, Universal Biology Institute, The University of Tokyo, Tokyo, Japan.
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7
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Bhattacharyya S, Bhattacharyya M, Pfannenstiel DM, Nandi AK, Hwang Y, Ho K, Harshey RM. Efflux-linked accelerated evolution of antibiotic resistance at a population edge. Mol Cell 2022; 82:4368-4385.e6. [PMID: 36400010 PMCID: PMC9699456 DOI: 10.1016/j.molcel.2022.10.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/22/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022]
Abstract
Efflux is a common mechanism of resistance to antibiotics. We show that efflux itself promotes accumulation of antibiotic-resistance mutations (ARMs). This phenomenon was initially discovered in a bacterial swarm where the linked phenotypes of high efflux and high mutation frequencies spatially segregated to the edge, driven there by motility. We have uncovered and validated a global regulatory network connecting high efflux to downregulation of specific DNA-repair pathways even in non-swarming states. The efflux-DNA repair link was corroborated in a clinical "resistome" database: genomes with mutations that increase efflux exhibit a significant increase in ARMs. Accordingly, efflux inhibitors decreased evolvability to antibiotic resistance. Swarms also revealed how bacterial populations serve as a reservoir of ARMs even in the absence of antibiotic selection pressure. High efflux at the edge births mutants that, despite compromised fitness, survive there because of reduced competition. This finding is relevant to biofilms where efflux activity is high.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
| | | | - Dylan M Pfannenstiel
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Anjan K Nandi
- Department of Physical Sciences, Indian Institute of Science Education & Research, Kolkata, India
| | - YuneSahng Hwang
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Khang Ho
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Rasika M Harshey
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
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8
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Knecht CA, Krüger M, Kellmann S, Mäusezahl I, Möder M, Adelowo OO, Vollmers J, Kaster AK, Nivala J, Müller JA. Cellular stress affects the fate of microbial resistance to folate inhibitors in treatment wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157318. [PMID: 35839882 DOI: 10.1016/j.scitotenv.2022.157318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/11/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
The environmental prevalence of antimicrobial resistance (AMR) has come into focus under the One Health concept. Wastewater treatment systems are among the significant sources of AMR in the environment. In such systems, it is uncertain to which extent antimicrobials present at sub-inhibitory concentrations constitute a selective pressure for bacterial maintenance and acquisition of antibiotic resistance (AR) genes. Here, we mapped AMR to inhibitors of folate biosynthesis in an aerated and a non-aerated horizontal subsurface flow treatment wetland receiving the same pre-treated municipal wastewater. General water characteristics and the concentrations of folate inhibitors were determined to define the ambient conditions over the longitudinal axis of the two treatment wetlands. Profiling of AMR as well as class 1 integrons, a carrier of AR genes against folate inhibitors and other antimicrobials, was conducted by cultivation-dependent and -independent methods. The wetlands achieved mean reductions of AR gene copy numbers in the effluents of at least 2 log, with the aerated system performing better. The folate inhibitors had no noticeable effect on the prevalence of respective AR genes. However, there was a transient increase of AR gene copy numbers and AR gene cassette composition in class 1 integrons in the aerated wetland. The comparison of all data from both wetlands suggests that higher levels of cellular stress in the aerated system promoted the mobility of AR genes via enhancing the activity of the DNA recombinase of the class 1 integron. The findings highlight that environmental conditions that modulate the activity of this genetic element can be more important for the fate of associated AR genes in treatment wetlands than the ambient concentration of the respective antimicrobial agents. By extrapolation, the results suggest that cellular stress also contributes to the mobility of AR gene in other wastewater treatment systems.
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Affiliation(s)
- Camila A Knecht
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany; Otto-von-Guericke-University Magdeburg, FVST Chair Environmental Technology, Magdeburg, Germany
| | - Markus Krüger
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany; Institute of Biodiversity, Friedrich-Schiller-University Jena, Germany
| | - Simon Kellmann
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ines Mäusezahl
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Monika Möder
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Olawale O Adelowo
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany; Environmental Microbiology and Biotechnology Laboratory, Department of Microbiology, University of Ibadan, Ibadan, Nigeria
| | - John Vollmers
- Institute for Biological Interfaces (IBG5), Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Anne-Kristin Kaster
- Institute for Biological Interfaces (IBG5), Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Jaime Nivala
- Environmental and Biotechnology Centre (UBZ), Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany; Research Unit REVERSAAL, National Research Institute for Agriculture, Food and the Environment (INRAE), Villeurbanne, France
| | - Jochen A Müller
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany; Institute for Biological Interfaces (IBG5), Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
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9
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Bai K, Jiang N, Chen X, Xu X, Li J, Luo L. RNA-Seq Analysis Discovers the Critical Role of Rel in ppGpp Synthesis, Pathogenicity, and the VBNC State of Clavibacter michiganensis. PHYTOPATHOLOGY 2022; 112:1844-1858. [PMID: 35341314 DOI: 10.1094/phyto-01-22-0023-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The viable but nonculturable (VBNC) state is a unique survival strategy of bacteria in response to stress conditions. It was confirmed that Clavibacter michiganensis, the causal agent of bacterial canker in tomato, could be induced into the VBNC state by exposure to CuSO4 in an oligotrophic solution. RNA-sequencing analysis was used to monitor the mechanisms of the VBNC state during CuSO4 induction in C. michiganensis. The results identified that numerous genes involved in stringent response, copper resistance, and stress resistance were upregulated, and some involved in cell division were downregulated significantly. The study investigated the importance of Rel, which is an essential enzyme in the synthesis of the molecular alarmone ppGpp, via the generation of a Δrel mutant and its complementation strain. Biological characterization revealed that deficiency of rel reduced the bacterial growth, production of exopolysaccharides, and pathogenicity as well as ppGpp production. The Δrel mutant increased the sensitivity to environmental stress, exhibiting reduced growth on minimal media and a propensity to enter the VBNC state in response to CuSO4. These findings have important implications for the understanding of survival mechanism and management of C. michiganensis and other phytopathogenic bacteria.
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Affiliation(s)
- Kaihong Bai
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xing Chen
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xiaoli Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
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10
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Joffré E, Xiao X, Correia MSP, Nookaew I, Sasse S, Globisch D, Zhu B, Sjöling Å. Analysis of Growth Phases of Enterotoxigenic Escherichia coli Reveals a Distinct Transition Phase before Entry into Early Stationary Phase with Shifts in Tryptophan, Fucose, and Putrescine Metabolism and Degradation of Neurotransmitter Precursors. Microbiol Spectr 2022; 10:e0175521. [PMID: 35876501 PMCID: PMC9431495 DOI: 10.1128/spectrum.01755-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/03/2022] [Indexed: 11/20/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and adults in endemic areas. Gene regulation of ETEC during growth in vitro and in vivo needs to be further evaluated, and here we describe the full transcriptome and metabolome of ETEC during growth from mid-logarithmic growth to early stationary phase in rich medium (LB medium). We identified specific genes and pathways subjected to rapid transient alterations in gene expression and metabolite production during the transition from logarithmic to stationary growth. The transient phase was found to be different from the subsequent induction of early stationary phase-induced genes. The transient phase was characterized by the repression of genes and metabolites involved in organic substance transport. Genes involved in fucose and putrescine metabolism were upregulated, and genes involved in iron transport were repressed. Expression of toxins and colonization factors were not changed, suggesting retained virulence from mid-logarithmic to the start of the stationary phase. Metabolomic analyses showed that the transient phase was characterized by a drop of intracellular amino acids, e.g., l-tyrosine, l-tryptophan, l-phenylalanine, l-leucine, and l-glutamic acid, followed by increased levels at induction of stationary phase. A pathway enrichment analysis of the entire combined transcriptome and metabolome revealed that significant pathways during progression from logarithmic to early stationary phase are involved in the degradation of neurotransmitters aminobutyrate (GABA) and precursors of 5-hydroxytryptamine (serotonin). This work provides a comprehensive framework for further studies on transcriptional and metabolic regulation in pathogenic E. coli. IMPORTANCE We show that E. coli, exemplified by the pathogenic subspecies enterotoxigenic E. coli (ETEC), undergoes a stepwise transcriptional and metabolic transition into the stationary phase. At a specific entry point, E. coli induces activation and repression of specific pathways. This leads to a rapid decrease of intracellular levels of certain amino acids. The resulting metabolic activity leads to an intense but short peak of indole production, suggesting that this is the previously described "indole peak," rapid decrease of intermediate molecules of bacterial neurotransmitters, increased putrescine and fucose uptake, increased glutathione levels, and decreased iron uptake. This specific transient shift in gene expression and metabolome is short-lived and disappears when bacteria enter the early stationary phase. We suggest that these changes mainly prepare bacteria for ceased growth, but based on the pathways involved, we could suggest that this transient phase substantially influences survival and virulence.
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Affiliation(s)
- Enrique Joffré
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Xue Xiao
- CAS Key Laboratory of Pathogenic Microbiology & Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Mário S. P. Correia
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Intawat Nookaew
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Samantha Sasse
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Daniel Globisch
- Department of Chemistry - BMC, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Baoli Zhu
- CAS Key Laboratory of Pathogenic Microbiology & Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Åsa Sjöling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
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11
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The Gene Expression Profile Differs in Growth Phases of the Bifidobacterium Longum Culture. Microorganisms 2022; 10:microorganisms10081683. [PMID: 36014100 PMCID: PMC9415070 DOI: 10.3390/microorganisms10081683] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/16/2022] [Accepted: 08/19/2022] [Indexed: 11/21/2022] Open
Abstract
To date, transcriptomics have been widely and successfully employed to study gene expression in different cell growth phases of bacteria. Since bifidobacteria represent a major component of the gut microbiota of a healthy human that is associated with numerous health benefits for the host, it is important to study them using transcriptomics. In this study, we applied the RNA-Seq technique to study global gene expression of B. longum at different growth phases in order to better understand the response of bifidobacterial cells to the specific conditions of the human gut. We have shown that in the lag phase, ABC transporters, whose function may be linked to active substrate utilization, are increasingly expressed due to preparation for cell division. In the exponential phase, the functions of activated genes include synthesis of amino acids (alanine and arginine), energy metabolism (glycolysis/gluconeogenesis and nitrogen metabolism), and translation, all of which promote active cell division, leading to exponential growth of the culture. In the stationary phase, we observed a decrease in the expression of genes involved in the control of the rate of cell division and an increase in the expression of genes involved in defense-related metabolic pathways. We surmise that the latter ensures cell survival in the nutrient-deprived conditions of the stationary growth phase.
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L.B. Almeida B, M. Bahrudeen MN, Chauhan V, Dash S, Kandavalli V, Häkkinen A, Lloyd-Price J, S.D. Cristina P, Baptista ISC, Gupta A, Kesseli J, Dufour E, Smolander OP, Nykter M, Auvinen P, Jacobs HT, M.D. Oliveira S, S. Ribeiro A. The transcription factor network of E. coli steers global responses to shifts in RNAP concentration. Nucleic Acids Res 2022; 50:6801-6819. [PMID: 35748858 PMCID: PMC9262627 DOI: 10.1093/nar/gkac540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/02/2022] [Accepted: 06/14/2022] [Indexed: 12/24/2022] Open
Abstract
The robustness and sensitivity of gene networks to environmental changes is critical for cell survival. How gene networks produce specific, chronologically ordered responses to genome-wide perturbations, while robustly maintaining homeostasis, remains an open question. We analysed if short- and mid-term genome-wide responses to shifts in RNA polymerase (RNAP) concentration are influenced by the known topology and logic of the transcription factor network (TFN) of Escherichia coli. We found that, at the gene cohort level, the magnitude of the single-gene, mid-term transcriptional responses to changes in RNAP concentration can be explained by the absolute difference between the gene's numbers of activating and repressing input transcription factors (TFs). Interestingly, this difference is strongly positively correlated with the number of input TFs of the gene. Meanwhile, short-term responses showed only weak influence from the TFN. Our results suggest that the global topological traits of the TFN of E. coli shape which gene cohorts respond to genome-wide stresses.
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Affiliation(s)
- Bilena L.B. Almeida
- Correspondence may also be addressed to Bilena L.B. Almeida. Tel: +358 2945211;
| | | | | | | | - Vinodh Kandavalli
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Antti Häkkinen
- Research Program in Systems Oncology, Research Programs Unit, Faculty of Medicine, University of Helsinki, FI-00014 Helsinki, Finland
| | | | - Palma S.D. Cristina
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Ines S C Baptista
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Abhishekh Gupta
- Center for Quantitative Medicine and Department of Cell Biology, University of Connecticut School of Medicine, 263 Farmington Av., Farmington, CT 06030-6033, USA
| | - Juha Kesseli
- Prostate Cancer Research Center, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Tays Cancer Center, Tampere University Hospital, Tampere, Finland
| | - Eric Dufour
- Mitochondrial bioenergetics and metabolism, BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Olli-Pekka Smolander
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Matti Nykter
- Prostate Cancer Research Center, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Tays Cancer Center, Tampere University Hospital, Tampere, Finland
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland; Department of Environment and Genetics, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Samuel M.D. Oliveira
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
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Coulet M, Kepp O, Kroemer G, Basmaciogullari S. Metabolic Profiling of CHO Cells during the Production of Biotherapeutics. Cells 2022; 11:cells11121929. [PMID: 35741058 PMCID: PMC9221972 DOI: 10.3390/cells11121929] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/02/2022] [Accepted: 06/13/2022] [Indexed: 01/08/2023] Open
Abstract
As indicated by an ever-increasing number of FDA approvals, biotherapeutics constitute powerful tools for the treatment of various diseases, with monoclonal antibodies (mAbs) accounting for more than 50% of newly approved drugs between 2014 and 2018 (Walsh, 2018). The pharmaceutical industry has made great progress in developing reliable and efficient bioproduction processes to meet the demand for recombinant mAbs. Mammalian cell lines are preferred for the production of functional, complex recombinant proteins including mAbs, with Chinese hamster ovary (CHO) cells being used in most instances. Despite significant advances in cell growth control for biologics manufacturing, cellular responses to environmental changes need to be understood in order to further improve productivity. Metabolomics offers a promising approach for developing suitable strategies to unlock the full potential of cellular production. This review summarizes key findings on catabolism and anabolism for each phase of cell growth (exponential growth, the stationary phase and decline) with a focus on the principal metabolic pathways (glycolysis, the pentose phosphate pathway and the tricarboxylic acid cycle) and the families of biomolecules that impact these circuities (nucleotides, amino acids, lipids and energy-rich metabolites).
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Affiliation(s)
- Mathilde Coulet
- Sanofi R&D, 94400 Vitry-sur-Seine, France;
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, 94800 Villejuif, France;
| | - Oliver Kepp
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, 94800 Villejuif, France;
- Institut Universitaire de France, Centre de Recherche des Cordeliers, Equipe Labellisée par la Ligue Contre le Cancer, Université de Paris Cité, Sorbonne Université, Inserm U1138, 75006 Paris, France
| | - Guido Kroemer
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, 94800 Villejuif, France;
- Institut Universitaire de France, Centre de Recherche des Cordeliers, Equipe Labellisée par la Ligue Contre le Cancer, Université de Paris Cité, Sorbonne Université, Inserm U1138, 75006 Paris, France
- Department of Biology, Institut du Cancer Paris CARPEM, Hôpital Européen Georges Pompidou, AP-HP, 75015 Paris, France
- Correspondence: (G.K.); (S.B.)
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Veetilvalappil VV, Aranjani JM, Mahammad FS, Joseph A. Awakening sleeper cells: a narrative review on bacterial magic spot synthetases as potential drug targets to overcome persistence. Curr Genet 2022; 68:49-60. [PMID: 34787710 PMCID: PMC8801413 DOI: 10.1007/s00294-021-01221-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 10/29/2022]
Abstract
Magic spot synthetases are emerging targets to overcome persistence caused by stringent response. The 'stringent response' is a bacterial stress survival mechanism, which results in the accumulation of alarmones (also called Magic spots) leading to the formation of dormant persister cells. These 'sleeper cells' evade antibiotic treatment and could result in relapse of infection. This review broadly investigates the phenomenon of stringent response and persistence, and specifically discusses the distribution, classification, and nomenclature of proteins such as Rel/SpoT homologs (RSH), responsible for alarmone synthesis. The authors further explain the relevance of RSH as potential drug targets to break the dormancy of persister cells commonly seen in biofilms. One of the significant factors that initiate alarmone synthesis is nutrient deficiency. In a starved condition, ribosome-associated RSH detects deacylated tRNA and initiates alarmone synthesis. Accumulation of alarmones has a considerable effect on bacterial physiology, virulence, biofilm formation, and persister cell formation. Preventing alarmone synthesis by inhibiting RSH responsible for alarmone synthesis will prevent or reduce persister cells' formation. Magic spot synthetases are thus potential targets that could be explored to overcome persistence seen in biofilms.
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Affiliation(s)
- Vimal Venu Veetilvalappil
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
| | - Jesil Mathew Aranjani
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India.
| | - Fayaz Shaik Mahammad
- Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
| | - Alex Joseph
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
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The Role of RelA and SpoT on ppGpp Production, Stress Response, Growth Regulation, and Pathogenicity in Xanthomonas campestris pv. campestris. Microbiol Spectr 2021; 9:e0205721. [PMID: 34935430 PMCID: PMC8693919 DOI: 10.1128/spectrum.02057-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The alarmone ppGpp plays an important role in the survival of bacteria by triggering the stringent response when exposed to environmental stress. Although Xanthomonas campestris pv. campestris (Xcc), which causes black rot disease in crucifers, is a representative species of Gram-negative phytopathogenic bacteria, relatively little is known regarding the factors influencing the stringent response in this species. However, previous studies in other Gram-negative bacteria have indicated that RelA and SpoT play a critical role in ppGpp synthesis. The current study found that these proteins also had an important role in Xcc, with a ΔrelAΔspoT double mutant being unable to produce ppGpp, resulting in changes to phenotype including reduced production of exopolysaccharides (EPS), exoenzymes, and biofilm, as well the loss of swarming motility and pathogenicity. The ppGpp-deficient mutant also exhibited greater sensitivity to environment stress, being almost incapable of growth on modified minimal medium (mMM) and having a much greater propensity to enter the viable but nonculturable (VBNC) state in response to oligotrophic conditions (0.85% NaCl). These findings much advance our understanding of the role of ppGpp in the biology of Xcc and could have important implications for more effective management of this important pathogen. IMPORTANCEXanthomonas campestris pv. campestris (Xcc) is a typical seedborne phytopathogenic bacterium that causes large economic losses worldwide, and this is the first original research article to investigate the role of ppGpp in this important species. Here, we revealed the function of RelA and SpoT in ppGpp production, physiology, pathogenicity, and stress resistance in Xcc. Most intriguingly, we found that ppGpp levels and downstream ppGpp-dependent phenotypes were mediated predominantly by SpoT, with RelA having only a supplementary role. Taken together, the results of the current study provide new insight into the role of ppGpp in the biology of Xcc, which could also have important implications for the role of ppGpp in the survival and pathogenicity of other pathogenic bacteria.
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Tan YS, Wang L, Wang YY, He QE, Liu ZH, Zhu Z, Song K, Li BZ, Yuan YJ. Protein acetylation regulates xylose metabolism during adaptation of Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:241. [PMID: 34920742 PMCID: PMC8684234 DOI: 10.1186/s13068-021-02090-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND As the second most abundant polysaccharide in nature, hemicellulose can be degraded to xylose as the feedstock for bioconversion to fuels and chemicals. To enhance xylose conversion, the engineered Saccharomyces cerevisiae with xylose metabolic pathway is usually adapted with xylose as the carbon source in the laboratory. However, the mechanism under the adaptation phenomena of the engineered strain is still unclear. RESULTS In this study, xylose-utilizing S. cerevisiae was constructed and used for the adaptation study. It was found that xylose consumption rate increased 1.24-fold in the second incubation of the yYST12 strain in synthetic complete-xylose medium compared with the first incubation. The study figured out that it was observed at the single-cell level that the stagnation time for xylose utilization was reduced after adaptation with xylose medium in the microfluidic device. Such transient memory of xylose metabolism after adaptation with xylose medium, named "xylose consumption memory", was observed in the strains with both xylose isomerase pathway and xylose reductase and xylitol dehydrogenase pathways. In further, the proteomic acetylation of the strains before and after adaptation was investigated, and it was revealed that H4K5 was one of the most differential acetylation sites related to xylose consumption memory of engineered S. cerevisiae. We tested 8 genes encoding acetylase or deacetylase, and it was found that the knockout of the GCN5 and HPA2 encoding acetylases enhanced the xylose consumption memory. CONCLUSIONS The behavior of xylose consumption memory in engineered S. cerevisiae can be successfully induced with xylose in the adaptation. H4K5Ac and two genes of GCN5 and HPA2 are related to xylose consumption memory of engineered S. cerevisiae during adaptation. This study provides valuable insights into the xylose adaptation of engineered S. cerevisiae.
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Affiliation(s)
- Yong-Shui Tan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Li Wang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Ying-Ying Wang
- Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096 People’s Republic of China
| | - Qi-En He
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Zhen Zhu
- Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096 People’s Republic of China
| | - Kai Song
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
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Balakrishnan R, de Silva RT, Hwa T, Cremer J. Suboptimal resource allocation in changing environments constrains response and growth in bacteria. Mol Syst Biol 2021; 17:e10597. [PMID: 34928547 PMCID: PMC8687047 DOI: 10.15252/msb.202110597] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/13/2022] Open
Abstract
To respond to fluctuating conditions, microbes typically need to synthesize novel proteins. As this synthesis relies on sufficient biosynthetic precursors, microbes must devise effective response strategies to manage depleting precursors. To better understand these strategies, we investigate the active response of Escherichia coli to changes in nutrient conditions, connecting transient gene expression to growth phenotypes. By synthetically modifying gene expression during changing conditions, we show how the competition by genes for the limited protein synthesis capacity constrains cellular response. Despite this constraint cells substantially express genes that are not required, trapping them in states where precursor levels are low and the genes needed to replenish the precursors are outcompeted. Contrary to common modeling assumptions, our findings highlight that cells do not optimize growth under changing environments but rather exhibit hardwired response strategies that may have evolved to promote fitness in their native environment. The constraint and the suboptimality of the cellular response uncovered provide a conceptual framework relevant for many research applications, from the prediction of evolution to the improvement of gene circuits in biotechnology.
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Affiliation(s)
| | | | - Terence Hwa
- Department of PhysicsUniversity of California at San DiegoLa JollaCAUSA
- Division of Biological SciencesUniversity of California at San DiegoLa JollaCAUSA
| | - Jonas Cremer
- Department of BiologyStanford UniversityStanfordCAUSA
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Loss of the acetate switch in Vibrio vulnificus enhances predation defence against Tetrahymena pyriformis. Appl Environ Microbiol 2021; 88:e0166521. [PMID: 34731052 PMCID: PMC8788688 DOI: 10.1128/aem.01665-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio vulnificus is an opportunistic human pathogen and autochthonous inhabitant of coastal marine environments, where the bacterium is under constant predation by heterotrophic protists or protozoans. As a result of this selection pressure, genetic variants with antipredation mechanisms are selected for and persist in the environment. Such natural variants may also be pathogenic to animal or human hosts, making it important to understand these defense mechanisms. To identify antipredator strategies, 13 V. vulnificus strains of different genotypes isolated from diverse environments were exposed to predation by the ciliated protozoan Tetrahymena pyriformis, and only strain ENV1 was resistant to predation. Further investigation of the cell-free supernatant showed that ENV1 acidifies the environment by the excretion of organic acids, which are toxic to T. pyriformis. As this predation resistance was dependent on the availability of iron, transcriptomes of V. vulnificus in iron-replete and iron-deplete conditions were compared. This analysis revealed that ENV1 ferments pyruvate and the resultant acetyl-CoA leads to acetate synthesis under aerobic conditions, a hallmark of overflow metabolism. The anaerobic respiration global regulator arcA was upregulated when iron was available. An ΔarcA deletion mutant of ENV1 accumulated less acetate and, importantly, was sensitive to grazing by T. pyriformis. Based on the transcriptome response and quantification of metabolites, we conclude that ENV1 has adapted to overflow metabolism and has lost a control switch that shifts metabolism from acetate excretion to acetate assimilation, enabling it to excrete acetate continuously. We show that overflow metabolism and the acetate switch contribute to prey-predator interactions. IMPORTANCE Bacteria in the environment, including Vibrio spp., interact with protozoan predators. To defend against predation, bacteria evolve antipredator mechanisms ranging from changing morphology, biofilm formation, and secretion of toxins or virulence factors. Some of these adaptations may result in strains that are pathogenic to humans. Therefore, it is important to study predator defense strategies of environmental bacteria. V. vulnificus thrives in coastal waters and infects humans. Very little is known about the defense mechanisms V. vulnificus expresses against predation. Here, we show that a V. vulnificus strain (ENV1) has rewired the central carbon metabolism, enabling the production of excess organic acid that is toxic to the protozoan predator T. pyriformis. This is a previously unknown mechanism of predation defense that protects against protozoan predators.
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Zhao H, Lin J, Wang X, Shi J, Dahlgren RA, Xu J. Dynamics of Soil Microbial N-Cycling Strategies in Response to Cadmium Stress. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14305-14315. [PMID: 34617741 DOI: 10.1021/acs.est.1c04409] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Globally increasing trace metal contamination of soils requires a better mechanistic understanding of metal-stress impacts on microbially mediated nutrient cycling. Herein, a 5-month laboratory experiment was employed to assess the effects of cadmium (Cd) on soil microbial N-cycling processes and associated functional gene abundance, with and without urea amendment. In non-N-amended soils, Cd progressively stimulated microbial populations for N acquisition from initial dissolved organic N (DON) to later recalcitrant organic N. The acceleration of N catabolism was synchronously coupled with C catabolism resulting in increased CO2/N2O fluxes and adenosine triphosphate (ATP) contents. The abundance of microbes deemed inefficient in N catabolism was gradually repressed after an initial stimulation period. We posit that enhanced exergonic N processes diminished the need for endergonic activities as a survival strategy for N communities experiencing metal stress. With urea amendment, Cd exhibited an initial stimulation effect on soil nitrification and a later a promotion effect on mineralization, along with an increase in the associated microbial populations. In N-amended soils, Cd accelerated N/C transformation processes, but decreased N2O and CO2 fluxes by 19 and 14%, respectively. This implies that under eutrophic conditions, Cd synchronously altered microbial C/N metabolism from a dominance of catabolic to anabolic processes. These results infer a nutrient-based adjustment of microbial N-cycling strategies to enhance their metal resistance.
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Affiliation(s)
- Haochun Zhao
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Jiahui Lin
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Xuehua Wang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Jiachun Shi
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Randy A Dahlgren
- Department of Land, Air and Water Resources, University of California, Davis, California 95616, United States
| | - Jianming Xu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
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Johnston RD, Woodall BM, Harrison J, Campagna SR, Fozo EM. Removal of peptidoglycan and inhibition of active cellular processes leads to daptomycin tolerance in Enterococcus faecalis. PLoS One 2021; 16:e0254796. [PMID: 34297729 PMCID: PMC8301656 DOI: 10.1371/journal.pone.0254796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 07/04/2021] [Indexed: 11/19/2022] Open
Abstract
Daptomycin is a cyclic lipopeptide antibiotic used in the clinic for treatment of severe enterococcal infections. Recent reports indicate that daptomycin targets active cellular processes, specifically, peptidoglycan biosynthesis. Within, we examined the efficacy of daptomycin against Enterococcus faecalis under a range of environmental growth conditions including inhibitors that target active cellular processes. Daptomycin was far less effective against cells in late stationary phase compared to cells in exponential phase, and this was independent of cellular ATP levels. Further, the addition of either the de novo protein synthesis inhibitor chloramphenicol or the fatty acid biosynthesis inhibitor cerulenin induced survival against daptomycin far better than controls. Alterations in metabolites associated with peptidoglycan synthesis correlated with protection against daptomycin. This was further supported as removal of peptidoglycan induced physiological daptomycin tolerance, a synergistic relation between daptomycin and fosfomycin, an inhibitor of the fist committed step peptidoglycan synthesis, was observed, as well as an additive effect when daptomycin was combined with ampicillin, which targets crosslinking of peptidoglycan strands. Removal of the peptidoglycan of Enterococcus faecium, Staphylococcus aureus, and Bacillus subtilis also resulted in significant protection against daptomycin in comparison to whole cells with intact cell walls. Based on these observations, we conclude that bacterial growth phase and metabolic activity, as well as the presence/absence of peptidoglycan are major contributors to the efficacy of daptomycin.
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Affiliation(s)
- Rachel D. Johnston
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, United States of America
| | - Brittni M. Woodall
- Department of Chemistry, University of Tennessee, Knoxville, TN, United States of America
| | - Johnathan Harrison
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States of America
| | - Shawn R. Campagna
- Department of Chemistry, University of Tennessee, Knoxville, TN, United States of America
- Biological and Small Molecule Mass Spectrometry Core, University of Tennessee, Knoxville, TN, United States of America
| | - Elizabeth M. Fozo
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States of America
- * E-mail:
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Kong C, Beukema M, Wang M, de Haan BJ, de Vos P. Human milk oligosaccharides and non-digestible carbohydrates prevent adhesion of specific pathogens via modulating glycosylation or inflammatory genes in intestinal epithelial cells. Food Funct 2021; 12:8100-8119. [PMID: 34286788 DOI: 10.1039/d1fo00872b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Human milk oligosaccharides (hMOs) and non-digestible carbohydrates (NDCs) are known to inhibit the adhesion of pathogens to the gut epithelium, but the mechanisms involved are not well understood. Here, the effects of 2'-FL, 3-FL, DP3-DP10, DP10-DP60 and DP30-DP60 inulins and DM7, DM55 and DM69 pectins were studied on pathogen adhesion to Caco-2 cells. As the growth phase influences virulence, E. coli ET8, E. coli LMG5862, E. coli O119, E. coli WA321, and S. enterica subsp. enterica LMG07233 from both log and stationary phases were tested. Specificity for enteric pathogens was tested by including the lung pathogen K. pneumoniae LMG20218. Expression of the cell membrane glycosylation genes of galectin and glycocalyx and inflammatory genes was studied in the presence and absence of 2'-FL or NDCs. Inhibition of pathogen adhesion was observed for 2'-FL, inulins, and pectins. Pre-incubation with 2'-FL downregulated ICAM1, and pectins modified the glycosylation genes. In contrast, K. pneumoniae LMG20218 downregulated the inflammatory genes, but these were restored by pre-incubation with pectins, which reduced the adhesion of K. pneumoniae LMG20218. In addition, DM69 pectin significantly upregulated the inflammatory genes. 2'-FL and pectins but not inulins inhibited pathogen adhesion to the gut epithelial Caco-2 cells through changing the cell membrane glycosylation and inflammatory genes, but the effects were molecule-, pathogen-, and growth phase-dependent.
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Affiliation(s)
- Chunli Kong
- School of Food and Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, Beijing, 100048, China.
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22
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Abstract
Metabolic engineering reprograms cells to synthesize value-added products. In doing so, endogenous genes are altered and heterologous genes can be introduced to achieve the necessary enzymatic reactions. Dynamic regulation of metabolic flux is a powerful control scheme to alleviate and overcome the competing cellular objectives that arise from the introduction of these production pathways. This review explores dynamic regulation strategies that have demonstrated significant production benefits by targeting the metabolic node corresponding to a specific challenge. We summarize the stimulus-responsive control circuits employed in these strategies that determine the criterion for actuating a dynamic response and then examine the points of control that couple the stimulus-responsive circuit to a shift in metabolic flux.
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Affiliation(s)
- Cynthia Ni
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
| | - Christina V Dinh
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
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23
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Effects of the Quinone Oxidoreductase WrbA on Escherichia coli Biofilm Formation and Oxidative Stress. Antioxidants (Basel) 2021; 10:antiox10060919. [PMID: 34204135 PMCID: PMC8229589 DOI: 10.3390/antiox10060919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/30/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022] Open
Abstract
The effects of natural compounds on biofilm formation have been extensively studied, with the goal of identifying biofilm formation antagonists at sub-lethal concentrations. Salicylic and cinnamic acids are some examples of these compounds that interact with the quinone oxidoreductase WrbA, a potential biofilm modulator and an antibiofilm compound biomarker. However, WrbA’s role in biofilm development is still poorly understood. To investigate the key roles of WrbA in biofilm maturation and oxidative stress, Escherichia coli wild-type and ∆wrbA mutant strains were used. Furthermore, we reported the functional validation of WrbA as a molecular target of salicylic and cinnamic acids. The lack of WrbA did not impair planktonic growth, but rather affected the biofilm formation through a mechanism that depends on reactive oxygen species (ROS). The loss of WrbA function resulted in an ROS-sensitive phenotype that showed reductions in biofilm-dwelling cells, biofilm thickness, matrix polysaccharide content, and H2O2 tolerance. Endogenous oxidative events in the mutant strain generated a stressful condition to which the bacterium responded by increasing the catalase activity to compensate for the lack of WrbA. Cinnamic and salicylic acids inhibited the quinone oxidoreductase activity of purified recombinant WrbA. The effects of these antibiofilm molecules on WrbA function was proven for the first time.
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24
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Alencar VC, Silva JDFDS, Vilas Boas RO, Farnézio VM, de Maria YNLF, Aciole Barbosa D, Almeida AT, de Souza EM, Müller-Santos M, Jabes DL, Menegidio FB, Costa de Oliveira R, Rodrigues T, Tersariol ILDS, Walmsley AR, Nunes LR. The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis. Int J Mol Sci 2021; 22:ijms22115628. [PMID: 34073173 PMCID: PMC8198075 DOI: 10.3390/ijms22115628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.
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Affiliation(s)
- Valquíria Campos Alencar
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Alameda da Universidade, s/n, São Bernardo do Campo 09606-045, SP, Brazil; (V.C.A.); (J.d.F.d.S.S.); (V.M.F.); (T.R.)
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Juliana de Fátima dos Santos Silva
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Alameda da Universidade, s/n, São Bernardo do Campo 09606-045, SP, Brazil; (V.C.A.); (J.d.F.d.S.S.); (V.M.F.); (T.R.)
| | - Renata Ozelami Vilas Boas
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Vinícius Manganaro Farnézio
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Alameda da Universidade, s/n, São Bernardo do Campo 09606-045, SP, Brazil; (V.C.A.); (J.d.F.d.S.S.); (V.M.F.); (T.R.)
| | - Yara N. L. F. de Maria
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - David Aciole Barbosa
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Alex Tramontin Almeida
- Setor de Ciências Biológicas-Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Rua Cel. Francisco H. dos Santos, 100, Curitiba 81531-980, PR, Brazil; (A.T.A.); (E.M.d.S.); (M.M.-S.)
| | - Emanuel Maltempi de Souza
- Setor de Ciências Biológicas-Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Rua Cel. Francisco H. dos Santos, 100, Curitiba 81531-980, PR, Brazil; (A.T.A.); (E.M.d.S.); (M.M.-S.)
| | - Marcelo Müller-Santos
- Setor de Ciências Biológicas-Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Rua Cel. Francisco H. dos Santos, 100, Curitiba 81531-980, PR, Brazil; (A.T.A.); (E.M.d.S.); (M.M.-S.)
| | - Daniela L. Jabes
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Fabiano B. Menegidio
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Regina Costa de Oliveira
- Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido Xavier de Almeida Souza, 200, Mogi das Cruzes 08780-911, SP, Brazil; (R.O.V.B.); (Y.N.L.F.d.M.); (D.A.B.); (D.L.J.); (F.B.M.); (R.C.d.O.)
| | - Tiago Rodrigues
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Alameda da Universidade, s/n, São Bernardo do Campo 09606-045, SP, Brazil; (V.C.A.); (J.d.F.d.S.S.); (V.M.F.); (T.R.)
| | - Ivarne Luis dos Santos Tersariol
- Departamento de Bioquímica, Universidade Federal de São Paulo (UNIFESP), Rua Três de Maio, 100, São Paulo 04044-020, SP, Brazil;
| | - Adrian R. Walmsley
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK;
| | - Luiz R. Nunes
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Alameda da Universidade, s/n, São Bernardo do Campo 09606-045, SP, Brazil; (V.C.A.); (J.d.F.d.S.S.); (V.M.F.); (T.R.)
- Correspondence: ; Tel.: +55-11-4996-8371 (ext. 4996-3166)
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25
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Ziegler M, Zieringer J, Takors R. Transcriptional profiling of the stringent response mutant strain E. coli SR reveals enhanced robustness to large-scale conditions. Microb Biotechnol 2021; 14:993-1010. [PMID: 33369128 PMCID: PMC8085953 DOI: 10.1111/1751-7915.13738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/08/2020] [Accepted: 12/08/2020] [Indexed: 12/05/2022] Open
Abstract
In large-scale fed-batch production processes, microbes are exposed to heterogeneous substrate availability caused by long mixing times. Escherichia coli, the most common industrial host for recombinant protein production, reacts by recurring accumulation of the alarmone ppGpp and energetically wasteful transcriptional strategies. Here, we compare the regulatory responses of the stringent response mutant strain E. coli SR and its parent strain E. coli MG1655 to repeated nutrient starvation in a two-compartment scale-down reactor. Our data show that E. coli SR can withstand these stress conditions without a ppGpp-mediated stress response maintaining fully functional ammonium uptake and biomass formation. Furthermore, E. coli SR exhibited a substantially reduced short-term transcriptional response compared to E. coli MG1655 (less than half as many differentially expressed genes). E. coli SR proceeded adaptation via more general SOS response pathways by initiating negative regulation of transcription, translation and cell division. Our results show that locally induced stress responses propagating through the bioreactor do not result in cyclical induction and repression of genes in E. coli SR, but in a reduced and coordinated response, which makes it potentially suitable for large-scale production processes.
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Affiliation(s)
- Martin Ziegler
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Julia Zieringer
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Ralf Takors
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
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26
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Bai K, Chen X, Jiang N, Lyu Q, Li J, Luo L. Extraction and detection of guanosine 5'-diphosphate-3'-diphosphate in amino acid starvation cells of Clavibacter michiganensis. Braz J Microbiol 2021; 52:1573-1580. [PMID: 33837930 DOI: 10.1007/s42770-021-00488-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/29/2021] [Indexed: 10/21/2022] Open
Abstract
Guanosine 5'-diphosphate-3'-diphosphate (ppGpp) is a small molecule nucleotide alarmone that can accumulate under the amino acid starvation state and trigger the stringent response. This study reported the extraction of ppGpp from the Gram-positive bacteria Clavibacter michiganensis through methods using formic acid, lysozyme, or methanol. Following extraction, ppGpp was detected through ultra-high-performance liquid chromatography (UHPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The methanol method showed the highest extraction efficiency for ppGpp among the three methods tested. C. michiganensis cells in exponential growth phase was induced in amino acid starvation by serine hydroxamate (SHX) and used for ppGpp extraction and detection. When using the methanol extraction method, the results showed that ppGpp concentrations in SHX-treated samples were 15.645 nM, 17.656 nM, 20.372 nM, and 19.280 nM at 0 min, 15 min, 30 min and 1 h, respectively, when detected using LC-MS/MS. This is the first report on ppGpp extraction and detection in Clavibacter providing a new idea and approach for nucleotide detection and extraction in bacteria.
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Affiliation(s)
- Kaihong Bai
- Beijing Key Laboratory of Seed Disease Testing and Control, Department of Plant Pathology, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Xing Chen
- Beijing Key Laboratory of Seed Disease Testing and Control, Department of Plant Pathology, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Na Jiang
- Beijing Key Laboratory of Seed Disease Testing and Control, Department of Plant Pathology, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Qingyang Lyu
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, People's Republic of China
| | - Jianqiang Li
- Beijing Key Laboratory of Seed Disease Testing and Control, Department of Plant Pathology, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Laixin Luo
- Beijing Key Laboratory of Seed Disease Testing and Control, Department of Plant Pathology, China Agricultural University, Beijing, 100193, People's Republic of China.
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27
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Lopatkin AJ, Bening SC, Manson AL, Stokes JM, Kohanski MA, Badran AH, Earl AM, Cheney NJ, Yang JH, Collins JJ. Clinically relevant mutations in core metabolic genes confer antibiotic resistance. Science 2021; 371:371/6531/eaba0862. [PMID: 33602825 DOI: 10.1126/science.aba0862] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 09/16/2020] [Accepted: 12/18/2020] [Indexed: 12/17/2022]
Abstract
Although metabolism plays an active role in antibiotic lethality, antibiotic resistance is generally associated with drug target modification, enzymatic inactivation, and/or transport rather than metabolic processes. Evolution experiments of Escherichia coli rely on growth-dependent selection, which may provide a limited view of the antibiotic resistance landscape. We sequenced and analyzed E. coli adapted to representative antibiotics at increasingly heightened metabolic states. This revealed various underappreciated noncanonical genes, such as those related to central carbon and energy metabolism, which are implicated in antibiotic resistance. These metabolic alterations lead to lower basal respiration, which prevents antibiotic-mediated induction of tricarboxylic acid cycle activity, thus avoiding metabolic toxicity and minimizing drug lethality. Several of the identified metabolism-specific mutations are overrepresented in the genomes of >3500 clinical E. coli pathogens, indicating clinical relevance.
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Affiliation(s)
- Allison J Lopatkin
- Institute for Medical Engineering and Science and Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Wyss Institute for Biologically Inspired Engineering; Harvard University, Boston, MA, USA.,Department of Biology, Barnard College, New York, NY, USA.,Data Science Institute, Columbia University, New York, NY, USA.,Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, USA
| | - Sarah C Bening
- Institute for Medical Engineering and Science and Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Abigail L Manson
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jonathan M Stokes
- Institute for Medical Engineering and Science and Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Wyss Institute for Biologically Inspired Engineering; Harvard University, Boston, MA, USA
| | - Michael A Kohanski
- Department of Otorhinolaryngology-Head and Neck Surgery, Division of Rhinology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ahmed H Badran
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ashlee M Earl
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nicole J Cheney
- Ruy V. Lourenço Center for Emerging and Re-Emerging Pathogens, Rutgers New Jersey Medical School, Newark, NJ, USA.,Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Jason H Yang
- Ruy V. Lourenço Center for Emerging and Re-Emerging Pathogens, Rutgers New Jersey Medical School, Newark, NJ, USA.,Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - James J Collins
- Institute for Medical Engineering and Science and Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA. .,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Wyss Institute for Biologically Inspired Engineering; Harvard University, Boston, MA, USA.,Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA.,Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
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28
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Chow K, Sarkar A, Elhesha R, Cinaglia P, Ay A, Kahveci T. ANCA: Alignment-Based Network Construction Algorithm. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2021; 18:512-524. [PMID: 31226082 DOI: 10.1109/tcbb.2019.2923620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dynamic biological networks model changes in the network topology over time. However, often the topologies of these networks are not available at specific time points. Existing algorithms for studying dynamic networks often ignore this problem and focus only on the time points at which experimental data is available. In this paper, we develop a novel alignment based network construction algorithm, ANCA, that constructs the dynamic networks at the missing time points by exploiting the information from a reference dynamic network. Our experiments on synthetic and real networks demonstrate that ANCA predicts the missing target networks accurately, and scales to large-scale biological networks in practical time. Our analysis of an E. coli protein-protein interaction network shows that ANCA successfully identifies key temporal changes in the biological networks. Our analysis also suggests that by focusing on the topological differences in the network, our method can be used to find important genes and temporal functional changes in the biological networks.
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29
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Sivapragasam S, Ghosh A, Kumar S, Johnson DT, Grove A. Similar solutions to a common challenge: regulation of genes encoding Ralstonia solanacearum xanthine dehydrogenase. FEMS Microbiol Lett 2021; 368:6147036. [PMID: 33620442 DOI: 10.1093/femsle/fnab022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/19/2021] [Indexed: 12/14/2022] Open
Abstract
The stringent response involves accumulation of (p)ppGpp, and it ensures that survival is prioritized. Production of (p)ppGpp requires purine synthesis, and upregulation of an operon that encodes the purine salvage enzyme xanthine dehydrogenase (Xdh) has been observed during stringent response in some bacterial species, where direct binding of ppGpp to a TetR-family transcription factor is responsible for increased xdh gene expression. We show here that the plant pathogen Ralstonia solanacearum has a regulatory system in which the LysR-family transcription factor XanR controls expression of the xan operon; this operon encodes Xdh as well as other enzymes involved in purine salvage, which favor accumulation of xanthine. XanR bound upstream of the xan operon, a binding that was attenuated on addition of either ppGpp or cyclic di-guanosine monophosphate (c-di-GMP). Using a reporter in which enhanced green fluorescent protein (EGFP) is expressed under control of a modified xan promoter, XanR was shown to repress EGFP production. Our data suggest that R. solanacearum features a regulatory mechanism in which expression of genes encoding purine salvage enzymes is controlled by a transcription factor that belongs to a different protein family, yet performs similar regulatory functions.
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Affiliation(s)
- Smitha Sivapragasam
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Arpita Ghosh
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Sanjay Kumar
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Danté T Johnson
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Anne Grove
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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30
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Daer S, Goodwill JE, Ikuma K. Effect of ferrate and monochloramine disinfection on the physiological and transcriptomic response of Escherichia coli at late stationary phase. WATER RESEARCH 2021; 189:116580. [PMID: 33166917 DOI: 10.1016/j.watres.2020.116580] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/08/2020] [Accepted: 10/29/2020] [Indexed: 06/11/2023]
Abstract
Biological mechanisms of disinfection not only vary by disinfectant but also remain not well understood. We investigated the physiological and transcriptomic response of Escherichia coli at late stationary phase to ferrate and monochloramine in amended lake water. Although ferrate and monochloramine treatments similarly reduced culturable cell concentrations by 3-log10, 64% and 11% of treated cells were viable following monochloramine and ferrate treatment, respectively. This observed induction of viable but non-culturable (VBNC) state following monochloramine treatment but not ferrate is attributed to slower monochloramine disinfection kinetics (by 2.8 times) compared to ferrate. Transcriptomic analysis of E. coli at 15 min of exposure revealed that 3 times as many genes related to translation and transcription were downregulated by monochloramine compared to ferrate, suggesting that monochloramine treatment may be inducing VBNC through reduced protein synthesis and metabolism. Downregulation of universal stress response genes (rpoS, uspA) was attributed to growth-related physiological stressors during late stationary phase which may have contributed to the elevated expression levels of general stress responses pre-disinfection and, subsequently, their significant downregulation post-disinfection. Both disinfectants upregulated oxidative stress response genes (trxC, grxA, soxS), although levels of upregulation were time sensitive. This work shows that bacterial inactivation responses to disinfectants is mediated by complex molecular and growth-related responses.
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Affiliation(s)
- Sahar Daer
- Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA, United States; Environmental Sciences Interdepartmental Graduate Program, Iowa State University, Ames, IA, United States
| | - Joseph E Goodwill
- Department of Civil and Environmental Engineering, University of Rhode Island, United States
| | - Kaoru Ikuma
- Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA, United States; Environmental Sciences Interdepartmental Graduate Program, Iowa State University, Ames, IA, United States; Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.
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31
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Differential Protein Expression in Exponential and Stationary Growth Phases of Mycobacterium avium subsp. hominissuis 104. Molecules 2021; 26:molecules26020305. [PMID: 33435591 PMCID: PMC7827551 DOI: 10.3390/molecules26020305] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 12/03/2022] Open
Abstract
Mycobacterium avium complex (MAC) is the most common non-tuberculous mycobacterium (NTM) and causes different types of pulmonary diseases. While genomic and transcriptomic analysis of Mycobacterium avium 104 (M. avium 104) has been extensive, little is known about the proteomics of M. avium 104. We utilized proteomics technology to analyze the changes in the whole proteome of M. avium 104 during exponential and stationary growth phases. We found 12 dys-regulated proteins; the up-regulated protein hits in the stationary phase were involved in aminopeptidase, choline dehydrogenase, oxidoreductase, and ATP binding, while the down-regulated proteins in the stationary phase were acetyl-CoA acetyltransferase, universal stress protein, catalase peroxidase, and elongation factor (Tu). The differently expressed proteins between exponential and stationary phases were implicated in metabolism and stress response, pointing to the functional adaptation of the cells to the environment. Proteomic analysis in different growth phases could participate in understanding the course of infection, the mechanisms of virulence, the means of survival, and the possible targets for treatment.
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Carter MQ, Pham A, Huynh S, Parker CT, Miller A, He X, Hu B, Chain PSG. DNA adenine methylase, not the PstI restriction-modification system, regulates virulence gene expression in Shiga toxin-producing Escherichia coli. Food Microbiol 2020; 96:103722. [PMID: 33494894 DOI: 10.1016/j.fm.2020.103722] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/15/2020] [Accepted: 12/22/2020] [Indexed: 01/20/2023]
Abstract
We previously reported a distinct methylome between the two Shiga toxin-producing Escherichia coli (STEC) O145:H28 strains linked to the 2010 U.S. lettuce-associated outbreak (RM13514) and the 2007 Belgium ice cream-associated outbreak (RM13516), respectively. This difference was thought to be attributed to a prophage encoded type II restriction-modification system (PstI R-M) in RM13514. Here, we characterized this PstI R-M system in comparison to DNA adenine methylase (Dam), a highly conserved enzyme in γ proteobacteria, by functional genomics. Deficiency in Dam led to a differential expression of over 1000 genes in RM13514, whereas deficiency in PstI R-M only impacted a few genes transcriptionally. Dam regulated genes involved in diverse functions, whereas PstI R-M regulated genes mostly encoding transporters and adhesins. Dam regulated a large number of genes located on prophages, pathogenicity islands, and plasmids, including Shiga toxin genes, type III secretion system (TTSS) genes, and enterohemolysin genes. Production of Stx2 in dam mutant was significantly higher than in RM13514, supporting a role of Dam in maintaining lysogeny of Stx2-prophage. However, following mitomycin C treatment, Stx2 in RM13514 was significantly higher than that of dam or PstI R-M deletion mutant, implying that both Dam and PstI R-M contributed to maximum Stx2 production.
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Affiliation(s)
- Michelle Qiu Carter
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA.
| | - Antares Pham
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA
| | - Steven Huynh
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA
| | - Craig T Parker
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA
| | - Avalon Miller
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA
| | - Xiaohua He
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Foodborne Toxin and Detection Research Unit, Albany, CA, USA
| | - Bin Hu
- Biosecurity and Public Health Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Patrick S G Chain
- Biosecurity and Public Health Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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Escherichia coli Has a Unique Transcriptional Program in Long-Term Stationary Phase Allowing Identification of Genes Important for Survival. mSystems 2020; 5:5/4/e00364-20. [PMID: 32753505 PMCID: PMC7406224 DOI: 10.1128/msystems.00364-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Microbes live in complex and constantly changing environments, but it is difficult to replicate this in the laboratory. Escherichia coli has been used as a model organism in experimental evolution studies for years; specifically, we and others have used it to study evolution in complex environments by incubating the cells into long-term stationary phase (LTSP) in rich media. In LTSP, cells experience a variety of stresses and changing conditions. While we have hypothesized that this experimental system is more similar to natural environments than some other lab conditions, we do not yet know how cells respond to this environment biochemically or physiologically. In this study, we began to unravel the cells' responses to this environment by characterizing the transcriptome of cells during LTSP. We found that cells in LTSP have a unique transcriptional program and that several genes are uniquely upregulated or downregulated in this phase. Further, we identified two genes, cspB and cspI, which are most highly expressed in LTSP, even though these genes are primarily known to respond to cold shock. By competing cells lacking these genes with wild-type cells, we show that these genes are also important for survival during LTSP. These data can help identify gene products that may play a role in survival in this complex environment and lead to identification of novel functions of proteins.IMPORTANCE Experimental evolution studies have elucidated evolutionary processes, but usually in chemically well-defined and/or constant environments. Using complex environments is important to begin to understand how evolution may occur in natural environments, such as soils or within a host. However, characterizing the stresses that cells experience in these complex environments can be challenging. One way to approach this is by determining how cells biochemically acclimate to heterogenous environments. In this study, we began to characterize physiological changes by analyzing the transcriptome of cells in a dynamic complex environment. By characterizing the transcriptional profile of cells in long-term stationary phase, a heterogenous and stressful environment, we can begin to understand how cells physiologically and biochemically react to the laboratory environment, and how this compares to more-natural conditions.
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Cavaiuolo M, Chagneau C, Laalami S, Putzer H. Impact of RNase E and RNase J on Global mRNA Metabolism in the Cyanobacterium Synechocystis PCC6803. Front Microbiol 2020; 11:1055. [PMID: 32582060 PMCID: PMC7283877 DOI: 10.3389/fmicb.2020.01055] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/29/2020] [Indexed: 01/18/2023] Open
Abstract
mRNA levels result from an equilibrium between transcription and degradation. Ribonucleases (RNases) facilitate the turnover of mRNA, which is an important way of controlling gene expression, allowing the cells to adjust transcript levels to a changing environment. In contrast to the heterotrophic model bacteria Escherichia coli and Bacillus subtilis, RNA decay has not been studied in detail in cyanobacteria. Synechocystis sp. PCC6803 encodes orthologs of both E. coli and B. subtilis RNases, including RNase E and RNase J, respectively. We show that in vitro Sy RNases E and J have an endonucleolytic cleavage specificity that is very similar between them and also compared to orthologous enzymes from E. coli, B. subtilis, and Chlamydomonas. Moreover, Sy RNase J displays a robust 5′-exoribonuclease activity similar to B. subtilis RNase J1, but unlike the evolutionarily related RNase J in chloroplasts. Both nucleases are essential and gene deletions could not be fully segregated in Synechocystis. We generated partially disrupted strains of Sy RNase E and J that were stable enough to allow for their growth and characterization. A transcriptome analysis of these strains partially depleted for RNases E and J, respectively, allowed to observe effects on specific transcripts. RNase E altered the expression of a larger number of chromosomal genes and antisense RNAs compared to RNase J, which rather affects endogenous plasmid encoded transcripts. Our results provide the first description of the main transcriptomic changes induced by the partial depletion of two essential ribonucleases in cyanobacteria.
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Affiliation(s)
- Marina Cavaiuolo
- UMR 8261, CNRS, Institut de Biologie Physico-Chimique, Université de Paris, Paris, France
| | - Carine Chagneau
- UMR 8261, CNRS, Institut de Biologie Physico-Chimique, Université de Paris, Paris, France
| | - Soumaya Laalami
- UMR 8261, CNRS, Institut de Biologie Physico-Chimique, Université de Paris, Paris, France
| | - Harald Putzer
- UMR 8261, CNRS, Institut de Biologie Physico-Chimique, Université de Paris, Paris, France
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Hernandez-Valdes JA, van Gestel J, Kuipers OP. A riboswitch gives rise to multi-generational phenotypic heterogeneity in an auxotrophic bacterium. Nat Commun 2020; 11:1203. [PMID: 32139702 PMCID: PMC7058034 DOI: 10.1038/s41467-020-15017-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 02/13/2020] [Indexed: 12/26/2022] Open
Abstract
Auxotrophy, the inability to produce an organic compound essential for growth, is widespread among bacteria. Auxotrophic bacteria rely on transporters to acquire these compounds from their environment. Here, we study the expression of both low- and high-affinity transporters of the costly amino acid methionine in an auxotrophic lactic acid bacterium, Lactococcus lactis. We show that the high-affinity transporter (Met-transporter) is heterogeneously expressed at low methionine concentrations, resulting in two isogenic subpopulations that sequester methionine in different ways: one subpopulation primarily relies on the high-affinity transporter (high expression of the Met-transporter) and the other subpopulation primarily relies on the low-affinity transporter (low expression of the Met-transporter). The phenotypic heterogeneity is remarkably stable, inherited for tens of generations, and apparent at the colony level. This heterogeneity results from a T-box riboswitch in the promoter region of the met operon encoding the high-affinity Met-transporter. We hypothesize that T-box riboswitches, which are commonly found in the Lactobacillales, may play as-yet unexplored roles in the predominantly auxotrophic lifestyle of these bacteria.
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Affiliation(s)
- Jhonatan A Hernandez-Valdes
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, Netherlands
| | - Jordi van Gestel
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
- Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, Netherlands.
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36
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Zúñiga A, Aravena P, Pulgar R, Travisany D, Ortiz-Severín J, Chávez FP, Maass A, González M, Cambiazo V. Transcriptomic Changes of Piscirickettsia salmonis During Intracellular Growth in a Salmon Macrophage-Like Cell Line. Front Cell Infect Microbiol 2020; 9:426. [PMID: 31998656 PMCID: PMC6964531 DOI: 10.3389/fcimb.2019.00426] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/29/2019] [Indexed: 12/15/2022] Open
Abstract
Piscirickettsia salmonis is the causative agent of Piscirickettsiosis, a systemic infection of salmonid fish species. P. salmonis infects and survives in its host cell, a process that correlates with the expression of virulence factors including components of the type IVB secretion system. To gain further insights into the cellular and molecular mechanism behind the adaptive response of P. salmonis during host infection, we established an in vitro model of infection using the SHK-1 cell line from Atlantic salmon head kidney. The results indicated that in comparison to uninfected SHK-1 cells, infection significantly decreased cell viability after 10 days along with a significant increment of P. salmonis genome equivalents. At that time, the intracellular bacteria were localized within a spacious cytoplasmic vacuole. By using a whole-genome microarray of P. salmonis LF-89, the transcriptome of this bacterium was examined during intracellular growth in the SHK-1 cell line and exponential growth in broth. Transcriptome analysis revealed a global shutdown of translation during P. salmonis intracellular growth and suggested an induction of the stringent response. Accordingly, key genes of the stringent response pathway were up-regulated during intracellular growth as well as at stationary phase bacteria, suggesting a role of the stringent response on bacterial virulence. Our results also reinforce the participation of the Dot/Icm type IVB secretion system during P. salmonis infection and reveals many unexplored genes with potential roles in the adaptation to intracellular growth. Finally, we proposed that intracellular P. salmonis alternates between a replicative phase and a stationary phase in which the stringent response is activated.
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Affiliation(s)
- Alejandro Zúñiga
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.,Blue Genomics Chile, Puerto Varas, Chile
| | - Pamela Aravena
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.,FONDAP Center for Genome Regulation, Santiago, Chile
| | - Rodrigo Pulgar
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Dante Travisany
- FONDAP Center for Genome Regulation, Santiago, Chile.,Center for Mathematical Modeling (PIA AFB17001) and Department of Mathematical Engineering, Universidad de Chile - UMI CNRS 2807, Santiago, Chile
| | - Javiera Ortiz-Severín
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.,Laboratorio de Microbiología de Sistemas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Francisco P Chávez
- Center for Mathematical Modeling (PIA AFB17001) and Department of Mathematical Engineering, Universidad de Chile - UMI CNRS 2807, Santiago, Chile
| | - Alejandro Maass
- FONDAP Center for Genome Regulation, Santiago, Chile.,Center for Mathematical Modeling (PIA AFB17001) and Department of Mathematical Engineering, Universidad de Chile - UMI CNRS 2807, Santiago, Chile
| | - Mauricio González
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.,FONDAP Center for Genome Regulation, Santiago, Chile
| | - Verónica Cambiazo
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.,FONDAP Center for Genome Regulation, Santiago, Chile
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37
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McIntosh M, Eisenhardt K, Remes B, Konzer A, Klug G. Adaptation of the Alphaproteobacterium Rhodobacter sphaeroides to stationary phase. Environ Microbiol 2019; 21:4425-4445. [PMID: 31579997 DOI: 10.1111/1462-2920.14809] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 08/30/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022]
Abstract
Exhaustion of nutritional resources stimulates bacterial populations to adapt their growth behaviour. General mechanisms are known to facilitate this adaptation by sensing the environmental change and coordinating gene expression. However, the existence of such mechanisms among the Alphaproteobacteria remains unclear. This study focusses on global changes in transcript levels during growth under carbon-limiting conditions in a model Alphaproteobacterium, Rhodobacter sphaeroides, a metabolically diverse organism capable of multiple modes of growth including aerobic and anaerobic respiration, anaerobic anoxygenic photosynthesis and fermentation. We identified genes that showed changed transcript levels independently of oxygen levels during the adaptation to stationary phase. We selected a subset of these genes and subjected them to mutational analysis, including genes predicted to be involved in manganese uptake, polyhydroxybutyrate production and quorum sensing and an alternative sigma factor. Although these genes have not been previously associated with the adaptation to stationary phase, we found that all were important to varying degrees. We conclude that while R. sphaeroides appears to lack a rpoS-like master regulator of stationary phase adaptation, this adaptation is nonetheless enabled through the impact of multiple genes, each responding to environmental conditions and contributing to the adaptation to stationary phase.
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Affiliation(s)
- Matthew McIntosh
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Katrin Eisenhardt
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Bernhard Remes
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Anne Konzer
- Biomolecular Mass Spectrometry, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Gabriele Klug
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
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Bacterial metabolic state more accurately predicts antibiotic lethality than growth rate. Nat Microbiol 2019; 4:2109-2117. [PMID: 31451773 DOI: 10.1038/s41564-019-0536-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/08/2019] [Indexed: 01/19/2023]
Abstract
Growth rate and metabolic state of bacteria have been separately shown to affect antibiotic efficacy1-3. However, the two are interrelated as bacterial growth inherently imposes a metabolic burden4; thus, determining individual contributions from each is challenging5,6. Indeed, faster growth is often correlated with increased antibiotic efficacy7,8; however, the concurrent role of metabolism in that relationship has not been well characterized. As a result, a clear understanding of the interdependence between growth and metabolism, and their implications for antibiotic efficacy, are lacking9. Here, we measured growth and metabolism in parallel across a broad range of coupled and uncoupled conditions to determine their relative contribution to antibiotic lethality. We show that when growth and metabolism are uncoupled, antibiotic lethality uniformly depends on the bacterial metabolic state at the time of treatment, rather than growth rate. We further reveal a critical metabolic threshold below which antibiotic lethality is negligible. These findings were general for a wide range of conditions, including nine representative bactericidal drugs and a diverse range of Gram-positive and Gram-negative species (Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus). This study provides a cohesive metabolic-dependent basis for antibiotic-mediated cell death, with implications for current treatment strategies and future drug development.
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Bathke J, Konzer A, Remes B, McIntosh M, Klug G. Comparative analyses of the variation of the transcriptome and proteome of Rhodobacter sphaeroides throughout growth. BMC Genomics 2019; 20:358. [PMID: 31072330 PMCID: PMC6509803 DOI: 10.1186/s12864-019-5749-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/29/2019] [Indexed: 02/08/2023] Open
Abstract
Background In natural environments, bacteria must frequently cope with extremely scarce nutrients. Most studies focus on bacterial growth in nutrient replete conditions, while less is known about the stationary phase. Here, we are interested in global gene expression throughout all growth phases, including the adjustment to deep stationary phase. Results We monitored both the transcriptome and the proteome in cultures of the alphaproteobacterium Rhodobacter sphaeroides, beginning with the transition to stationary phase and at different points of the stationary phase and finally during exit from stationary phase (outgrowth) following dilution with fresh medium. Correlation between the transcriptomic and proteomic changes was very low throughout the growth phases. Surprisingly, even in deep stationary phase, the abundance of many proteins continued to adjust, while the transcriptome analysis revealed fewer adjustments. This pattern was reversed during the first 90 min of outgrowth, although this depended upon the duration of the stationary phase. We provide a detailed analysis of proteomic changes based on the clustering of orthologous groups (COGs), and compare these with the transcriptome. Conclusions The low correlation between transcriptome and proteome supports the view that post-transcriptional processes play a major role in the adaptation to growth conditions. Our data revealed that many proteins with functions in transcription, energy production and conversion and the metabolism and transport of amino acids, carbohydrates, lipids, and secondary metabolites continually increased in deep stationary phase. Based on these findings, we conclude that the bacterium responds to sudden changes in environmental conditions by a radical and rapid reprogramming of the transcriptome in the first 90 min, while the proteome changes were modest. In response to gradually deteriorating conditions, however, the transcriptome remains mostly at a steady state while the bacterium continues to adjust its proteome. Even long after the population has entered stationary phase, cells are still actively adjusting their proteomes. Electronic supplementary material The online version of this article (10.1186/s12864-019-5749-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jochen Bathke
- Institute of Bioinformatics, University of Giessen, Giessen, Germany
| | - Anne Konzer
- Biomolecular Mass Spectrometry, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Bernhard Remes
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | - Matthew McIntosh
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany.
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
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40
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Ramos-Zúñiga J, Gallardo S, Martínez-Bussenius C, Norambuena R, Navarro CA, Paradela A, Jerez CA. Response of the biomining Acidithiobacillus ferrooxidans to high cadmium concentrations. J Proteomics 2019; 198:132-144. [DOI: 10.1016/j.jprot.2018.12.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 11/28/2022]
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41
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Xu Z, You D, Tang LY, Zhou Y, Ye BC. Metabolic Engineering Strategies Based on Secondary Messengers (p)ppGpp and C-di-GMP To Increase Erythromycin Yield in Saccharopolyspora erythraea. ACS Synth Biol 2019; 8:332-345. [PMID: 30632732 DOI: 10.1021/acssynbio.8b00372] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Secondary messengers (such as (p)ppGpp and c-di-GMP) were proved to play important roles in antibiotic biosynthesis in actinobacteria. In this study, we found that transcription levels of erythromycin-biosynthetic ( ery) genes were upregulated in nutrient limitation, which depended on (p)ppGpp in Saccharopolyspora erythraea. Further study demonstrated that the expression of ery genes and intracellular concentrations of (p)ppGpp showed synchronization during culture process. The erythromycin yield was significantly improved (about 200%) by increasing intracellular concentration of (p)ppGpp through introduction of C-terminally truncated (p)ppGpp synthetase RelA (1.43 kb of the N-terminal segment) from Streptomyces coelicolor into S. erythraea strain NRRL2338 (named as WT/pIB-P BAD- relA1-489). As the intracellular concentration of (p)ppGpp in an industrial erythromycin-high-producing strain E3 was greatly higher (about 10- to 100-fold) than WT strain, the applications of the above-described strategy did not work in E3 strain. Further research revealed that low concentration of 2-oxoglutarate in E3 strain exerted a "nitrogen-rich" pseudosignal, leading to the downregulation of nitrogen metabolism genes, which limited the use of nitrogen sources and thus the high intracellular (p)ppGpp concentration. Furthermore, the secondary messenger, c-di-GMP, was proved to be able to activate ery genes transcription by enhancing binding of BldD to promoters of ery genes. Overexpressing the diguanylate cyclase CdgB from S. coelicolor in S. erythraea increased the intracellular c-di-GMP concentration, and improved erythromycin production. These findings demonstrated that increasing the concentration of intracellular secondary messengers can activate ery genes transcription, and provided new strategies for designing metabolic engineering based on secondary messengers to improve antibiotics yield in actinobacteria.
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Affiliation(s)
- Zhen Xu
- Institute of Engineering Biology and Health, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Di You
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Li-Ya Tang
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Ying Zhou
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Bang-Ce Ye
- Institute of Engineering Biology and Health, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
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Wilding KM, Hunt JP, Wilkerson JW, Funk PJ, Swensen RL, Carver WC, Christian ML, Bundy BC. Endotoxin-Free E. coli-
Based Cell-Free Protein Synthesis: Pre-Expression Endotoxin Removal Approaches for on-Demand Cancer Therapeutic Production. Biotechnol J 2018; 14:e1800271. [DOI: 10.1002/biot.201800271] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/12/2018] [Indexed: 01/26/2023]
Affiliation(s)
- Kristen M. Wilding
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | - John P. Hunt
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | - Joshua W. Wilkerson
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | - Parker J. Funk
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | - Rebecca L. Swensen
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | - William C. Carver
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
| | | | - Bradley C. Bundy
- Chemical Engineering; Brigham Young University; 350 Clyde Provo UT 84602 USA
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Superoxide dismutase activity confers (p)ppGpp-mediated antibiotic tolerance to stationary-phase Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2018; 115:9797-9802. [PMID: 30201715 PMCID: PMC6166797 DOI: 10.1073/pnas.1804525115] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Metabolically quiescent bacteria represent a large proportion of those in natural and host environments, and they are often refractory to antibiotic treatment. Such drug tolerance is also observed in the laboratory during stationary phase, when bacteria face stress and starvation-induced growth arrest. Tolerance requires (p)ppGpp signaling, which mediates the stress and starvation stringent response (SR), but the downstream effectors that confer tolerance are unclear. We previously demonstrated that the SR is linked to increased antioxidant defenses in Pseudomonas aeruginosa We now demonstrate that superoxide dismutase (SOD) activity is a key factor in SR-mediated multidrug tolerance in stationary-phase P. aeruginosa Inactivation of the SR leads to loss of SOD activity and decreased multidrug tolerance during stationary phase. Genetic or chemical complementation of SOD activity of the ΔrelA spoT mutant (ΔSR) is sufficient to restore antibiotic tolerance to WT levels. Remarkably, we observe high membrane permeability and increased drug internalization upon ablation of SOD activity. Combined, our results highlight an unprecedented mode of SR-mediated multidrug tolerance in stationary-phase P. aeruginosa and suggest that inhibition of SOD activity may potentiate current antibiotics.
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Genome-Wide Quantification of the Effect of Gene Overexpression on Escherichia coli Growth. Genes (Basel) 2018; 9:genes9080414. [PMID: 30115866 PMCID: PMC6116040 DOI: 10.3390/genes9080414] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 12/18/2022] Open
Abstract
Recombinant protein production plays an essential role in both biological studies and pharmaceutical production. Escherichia coli is one of the most favorable hosts for this purpose. Although a number of strategies for optimizing protein production have been developed, the effect of gene overexpression on host cell growth has been much less studied. Here, we performed high-throughput tests on the E. coli a complete set of E. coli K-12 ORF archive (ASKA) collection to quantify the effects of overexpressing individual E. coli genes on its growth. The results indicated that overexpressing membrane-associated proteins or proteins with high abundances of branched-chain amino acids tended to impair cell growth, the latter of which could be remedied by amino acid supplementation. Through this study, we expect to provide an index for a fast pre-study estimate of host cell growth in order to choose proper rescuing approaches when working with different proteins.
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Smith A, Kaczmar A, Bamford RA, Smith C, Frustaci S, Kovacs-Simon A, O'Neill P, Moore K, Paszkiewicz K, Titball RW, Pagliara S. The Culture Environment Influences Both Gene Regulation and Phenotypic Heterogeneity in Escherichia coli. Front Microbiol 2018; 9:1739. [PMID: 30158905 PMCID: PMC6104134 DOI: 10.3389/fmicb.2018.01739] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 07/11/2018] [Indexed: 11/13/2022] Open
Abstract
Microorganisms shape the composition of the medium they are growing in, which in turn has profound consequences on the reprogramming of the population gene-expression profile. In this paper, we investigate the progressive changes in pH and sugar availability in the medium of a growing Escherichia coli (E. coli) culture. We show how these changes have an effect on both the cellular heterogeneity within the microbial community and the gene-expression profile of the microbial population. We measure the changes in gene-expression as E. coli moves from lag, to exponential, and finally into stationary phase. We found that pathways linked to the changes in the medium composition such as ribosomal, tricarboxylic acid cycle (TCA), transport, and metabolism pathways are strongly regulated during the different growth phases. In order to quantify the corresponding temporal changes in the population heterogeneity, we measure the fraction of E. coli persisters surviving different antibiotic treatments during the various phases of growth. We show that the composition of the medium in which β-lactams or quinolones, but not aminoglycosides, are dissolved strongly affects the measured phenotypic heterogeneity within the culture. Our findings contribute to a better understanding on how the composition of the culture medium influences both the reprogramming in the population gene-expression and the emergence of phenotypic variants.
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Affiliation(s)
- Ashley Smith
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | - Agnieszka Kaczmar
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | - Rosemary A Bamford
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | | | - Simona Frustaci
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | | | - Paul O'Neill
- Biosciences, University of Exeter, Exeter, United Kingdom
| | - Karen Moore
- Biosciences, University of Exeter, Exeter, United Kingdom
| | | | | | - Stefano Pagliara
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
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46
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DeVilbiss F, Mandli A, Ramkrishna D. Consistency of cybernetic variables with gene expression profiles: A more rigorous test. Biotechnol Prog 2018; 34:858-867. [PMID: 29708637 DOI: 10.1002/btpr.2654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 02/11/2018] [Indexed: 11/11/2022]
Abstract
Diauxic growth of Escherichia coli is driven by a host of internal, complex regulatory actions. In this classic scenario of cellular control, the cell employs a rational algorithm to modulate its metabolism in a competitive fashion. Cybernetic models of metabolism, whose development now spans three decades, were first formulated to describe regulation of cells in complex, multi-substrate environments. They modeled this scenario using the hypothesis that the formation of the enzymatic machinery is regulated to maximize a return on investment. While this assumption is made on the basis of logical arguments rooted in evolutionary principles, little effort has been taken to validate if enzymes are truly synthesized in the same fashion that is predicted by cybernetic variables. This work revisits the original cybernetic models describing diauxic growth and compares their predictions of enzyme synthesis control with time series gene expression data in microarray and qRT-PCR formats. Three separate studies are made for two different strains of E. coli. The first is for the growth of E. coli BW25113 on a mixture of glucose and acetate, whose gene expression changes are metered by microarray. Another is also for the sequential consumption of glucose and acetate but involves strain MG1655 and employs qRT-PCR. The final is for E. coli MG1655 on glucose and lactose. By demonstrating how cybernetic variables for induced enzyme synthesis mimic the behavior of transcriptional data, a strong argument for using cybernetic models is made. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:858-867, 2018.
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Affiliation(s)
- Frank DeVilbiss
- School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907
| | - Aravinda Mandli
- School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907
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47
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Cerletti M, Giménez MI, Tröetschel C, D' Alessandro C, Poetsch A, De Castro RE, Paggi RA. Proteomic Study of the Exponential-Stationary Growth Phase Transition in the Haloarchaea Natrialba magadii and Haloferax volcanii. Proteomics 2018; 18:e1800116. [PMID: 29888524 DOI: 10.1002/pmic.201800116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/09/2018] [Indexed: 11/12/2022]
Abstract
The dynamic changes that take place along the phases of microbial growth (lag, exponential, stationary, and death) have been widely studied in bacteria at the molecular and cellular levels, but little is known for archaea. In this study, a high-throughput approach was used to analyze and compare the proteomes of two haloarchaea during exponential and stationary growth: the neutrophilic Haloferax volcanii and the alkaliphilic Natrialba magadii. Almost 2000 proteins were identified in each species (≈50% of the predicted proteome). Among them, 532 and 432 were found to be differential between growth phases in H. volcanii and N. magadii, respectively. Changes upon entrance into stationary phase included an overall increase in proteins involved in the transport of small molecules and ions, stress response, and fatty acid catabolism. Proteins related to genetic processes and cell division showed a notorious decrease in amount. The data reported in this study not only contributes to our understanding of the exponential-stationary growth phase transition in extremophilic archaea but also provides the first comprehensive analysis of the proteome composition of N. magadii. The MS proteomics data have been deposited in the ProteomeXchange Consortium with the dataset identifier JPST000395.
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Affiliation(s)
- Micaela Cerletti
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Mar del Plata, 7600, Argentina
| | - María Ines Giménez
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Mar del Plata, 7600, Argentina
| | | | - Celeste D' Alessandro
- Laboratório de Patologia e Controle Microbiano de Insetos, ESALQ-USP, Piracicaba-SP, 13418-900, Brazil
| | - Ansgar Poetsch
- Plant Biochemistry, Ruhr University Bochum, Bochum, 44801, Germany.,School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, PL4 8AA, United Kingdom
| | - Rosana Ester De Castro
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Mar del Plata, 7600, Argentina
| | - Roberto A Paggi
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Mar del Plata, 7600, Argentina
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48
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Lázár V, Martins A, Spohn R, Daruka L, Grézal G, Fekete G, Számel M, Jangir PK, Kintses B, Csörgő B, Nyerges Á, Györkei Á, Kincses A, Dér A, Walter FR, Deli MA, Urbán E, Hegedűs Z, Olajos G, Méhi O, Bálint B, Nagy I, Martinek TA, Papp B, Pál C. Antibiotic-resistant bacteria show widespread collateral sensitivity to antimicrobial peptides. Nat Microbiol 2018; 3:718-731. [PMID: 29795541 DOI: 10.1038/s41564-018-0164-0] [Citation(s) in RCA: 236] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 04/17/2018] [Indexed: 01/28/2023]
Abstract
Antimicrobial peptides are promising alternative antimicrobial agents. However, little is known about whether resistance to small-molecule antibiotics leads to cross-resistance (decreased sensitivity) or collateral sensitivity (increased sensitivity) to antimicrobial peptides. We systematically addressed this question by studying the susceptibilities of a comprehensive set of 60 antibiotic-resistant Escherichia coli strains towards 24 antimicrobial peptides. Strikingly, antibiotic-resistant bacteria show a high frequency of collateral sensitivity to antimicrobial peptides, whereas cross-resistance is relatively rare. We identify clinically relevant multidrug-resistance mutations that increase bacterial sensitivity to antimicrobial peptides. Collateral sensitivity in multidrug-resistant bacteria arises partly through regulatory changes shaping the lipopolysaccharide composition of the bacterial outer membrane. These advances allow the identification of antimicrobial peptide-antibiotic combinations that enhance antibiotic activity against multidrug-resistant bacteria and slow down de novo evolution of resistance. In particular, when co-administered as an adjuvant, the antimicrobial peptide glycine-leucine-amide caused up to 30-fold decrease in the antibiotic resistance level of resistant bacteria. Our work provides guidelines for the development of efficient peptide-based therapies of antibiotic-resistant infections.
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Affiliation(s)
- Viktória Lázár
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ana Martins
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Réka Spohn
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Lejla Daruka
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Gábor Grézal
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Gergely Fekete
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mónika Számel
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Pramod K Jangir
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Bálint Kintses
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Bálint Csörgő
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ákos Nyerges
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ádám Györkei
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Kincses
- Biomolecular Electronics Research Group, Bionanoscience Unit, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Dér
- Biomolecular Electronics Research Group, Bionanoscience Unit, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Fruzsina R Walter
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mária A Deli
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Edit Urbán
- Institute of Clinical Microbiology, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zsófia Hegedűs
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Gábor Olajos
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Orsolya Méhi
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | | | - István Nagy
- SeqOmics Biotechnology Ltd, Mórahalom, Hungary.,Sequencing Platform, Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Tamás A Martinek
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Balázs Papp
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
| | - Csaba Pál
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
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49
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Lee AJ, Wang S, Meredith HR, Zhuang B, Dai Z, You L. Robust, linear correlations between growth rates and β-lactam-mediated lysis rates. Proc Natl Acad Sci U S A 2018; 115:4069-4074. [PMID: 29610312 PMCID: PMC5910845 DOI: 10.1073/pnas.1719504115] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It is widely acknowledged that faster-growing bacteria are killed faster by β-lactam antibiotics. This notion serves as the foundation for the concept of bacterial persistence: dormant bacterial cells that do not grow are phenotypically tolerant against β-lactam treatment. Such correlation has often been invoked in the mathematical modeling of bacterial responses to antibiotics. Due to the lack of thorough quantification, however, it is unclear whether and to what extent the bacterial growth rate can predict the lysis rate upon β-lactam treatment under diverse conditions. Enabled by experimental automation, here we measured >1,000 growth/killing curves for eight combinations of antibiotics and bacterial species and strains, including clinical isolates of bacterial pathogens. We found that the lysis rate of a bacterial population linearly depends on the instantaneous growth rate of the population, regardless of how the latter is modulated. We further demonstrate that this predictive power at the population level can be explained by accounting for bacterial responses to the antibiotic treatment by single cells. This linear dependence of the lysis rate on the growth rate represents a dynamic signature associated with each bacterium-antibiotic pair and serves as the quantitative foundation for designing combination antibiotic therapy and predicting the population-structure change in a population with mixed phenotypes.
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Affiliation(s)
- Anna J Lee
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Shangying Wang
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Hannah R Meredith
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Bihan Zhuang
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Zhuojun Dai
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, NC 27708;
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27708
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
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50
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A Vaginal Tract Signal Detected by the Group B Streptococcus SaeRS System Elicits Transcriptomic Changes and Enhances Murine Colonization. Infect Immun 2018; 86:IAI.00762-17. [PMID: 29378799 DOI: 10.1128/iai.00762-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/19/2018] [Indexed: 01/08/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) can colonize the human vaginal tract, leading to both superficial and serious infections in adults and neonates. To study bacterial colonization of the reproductive tract in a mammalian system, we employed a murine vaginal carriage model. Using transcriptome sequencing (RNA-Seq), the transcriptome of GBS growing in vivo during vaginal carriage was determined. Over one-quarter of the genes in GBS were found to be differentially regulated during in vivo colonization compared to laboratory cultures. A two-component system (TCS) homologous to the staphylococcal virulence regulator SaeRS was identified as being upregulated in vivo One of the SaeRS targets, pbsP, a proposed GBS vaccine candidate, is shown to be important for colonization of the vaginal tract. A component of vaginal lavage fluid acts as a signal to turn on pbsP expression via SaeRS. These data demonstrate the ability to quantify RNA expression directly from the murine vaginal tract and identify novel genes involved in vaginal colonization by GBS. They also provide more information about the regulation of an important virulence and colonization factor of GBS, pbsP, by the TCS SaeRS.
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