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Hu Z, Chin Y, Yuan C, Ge Y, Hang Y, Wang D, Yao Q, Hu Y. The luxS deletion reduces the spoilage ability of Shewanella putrefaciens: An analysis focusing on quorum sensing and activated methyl cycle. Food Microbiol 2024; 120:104467. [PMID: 38431319 DOI: 10.1016/j.fm.2024.104467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/02/2024] [Accepted: 01/08/2024] [Indexed: 03/05/2024]
Abstract
The luxS mutant strains of Shewanella putrefaciens (SHP) were constructed to investigate the regulations of gene luxS in spoilage ability. The potential regulations of AI-2 quorum sensing (QS) system and activated methyl cycle (AMC) were studied by analyzing the supplementation roles of key circulating substances mediated via luxS, including S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), methionine (Met), homocysteine (Hcy) and 4,5-dihydroxy-2,3-pentanedione (DPD). Growth experiments revealed that the luxS deletion led to certain growth limitations of SHP, which were associated with culture medium and exogenous additives. Meanwhile, the decreased biofilm formation and diminished hydrogen sulfide (H2S) production capacity of SHP were observed after luxS deletion. The relatively lower total volatile base nitrogen (TVB-N) contents and higher sensory scores of fish homogenate with luxS mutant strain inoculation also indicated the weaker spoilage-inducing effects after luxS deletion. However, these deficiencies could be offset with the exogenous supply of circulating substances mentioned above. Our findings suggested that the luxS deletion would reduce the spoilage ability of SHP, which was potentially attributed to the disorder of AMC and AI-2 QS system.
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Affiliation(s)
- Zhiheng Hu
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China; United Graduate School of Agricultural Sciences, Ueda 3-8-18, Morioka, Iwate 020-8550, Japan
| | - Yaoxian Chin
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China
| | - Chunhong Yuan
- Faculty of Agriculture, Iwate University, Ueda 3-8-18, Morioka, Iwate 020-8550, Japan; Agri-Innovation Center, Iwate University, Ueda 3-8-18, Morioka, Iwate 020-8550, Japan
| | - Yingliang Ge
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China
| | - Yuyu Hang
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China
| | - Dongxue Wang
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China
| | - Qian Yao
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu 610106, China
| | - Yaqin Hu
- College of Food Science and Engineering, Hainan Tropical Ocean University, Yazhou Bay Innovation Institute, Marine Food Engineering Technology Research Center of Hainan Province, Collaborative Innovation Center of Marine Food Deep Processing, Sanya 572022, China.
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Patel L, Ailloud F, Suerbaum S, Josenhans C. Single-base resolution quantitative genome methylation analysis in the model bacterium Helicobacter pylori by enzymatic methyl sequencing (EM-Seq) reveals influence of strain, growth phase, and methyl homeostasis. BMC Biol 2024; 22:125. [PMID: 38807090 PMCID: PMC11134628 DOI: 10.1186/s12915-024-01921-1] [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: 01/14/2024] [Accepted: 05/16/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Bacterial epigenetics is a rapidly expanding research field. DNA methylation by diverse bacterial methyltransferases (MTases) contributes to genomic integrity and replication, and many recent studies extended MTase function also to global transcript regulation and phenotypic variation. Helicobacter pylori is currently one of those bacterial species which possess the highest number and the most variably expressed set of DNA MTases. Next-generation sequencing technologies can directly detect DNA base methylation. However, they still have limitations in their quantitative and qualitative performance, in particular for cytosine methylation. RESULTS As a complementing approach, we used enzymatic methyl sequencing (EM-Seq), a technology recently established that has not yet been fully evaluated for bacteria. Thereby, we assessed quantitatively, at single-base resolution, whole genome cytosine methylation for all methylated cytosine motifs in two different H. pylori strains and isogenic MTase mutants. EM-Seq reliably detected both m5C and m4C methylation. We demonstrated that three different active cytosine MTases in H. pylori provide considerably different levels of average genome-wide single-base methylation, in contrast to isogenic mutants which completely lost specific motif methylation. We found that strain identity and changed environmental conditions, such as growth phase and interference with methyl donor homeostasis, significantly influenced quantitative global and local genome-wide methylation in H. pylori at specific motifs. We also identified significantly hyper- or hypo-methylated cytosines, partially linked to overlapping MTase target motifs. Notably, we revealed differentially methylated cytosines in genome-wide coding regions under conditions of methionine depletion, which can be linked to transcript regulation. CONCLUSIONS This study offers new knowledge on H. pylori global and local genome-wide methylation and establishes EM-Seq for quantitative single-site resolution analyses of bacterial cytosine methylation.
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Affiliation(s)
- Lubna Patel
- Max von Pettenkofer Institute, Chair for Medical Microbiology, Faculty of Medicine, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany
| | - Florent Ailloud
- Max von Pettenkofer Institute, Chair for Medical Microbiology, Faculty of Medicine, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany
| | - Sebastian Suerbaum
- Max von Pettenkofer Institute, Chair for Medical Microbiology, Faculty of Medicine, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany
| | - Christine Josenhans
- Max von Pettenkofer Institute, Chair for Medical Microbiology, Faculty of Medicine, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.
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3
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Ashok AK, Gnanasekaran TS, Santosh Kumar HS, Srikanth K, Prakash N, Gollapalli P. High-throughput screening and molecular dynamics simulations of natural products targeting LuxS/AI-2 system as a novel antibacterial strategy for antibiotic resistance in Helicobacter pylori. J Biomol Struct Dyn 2024; 42:2913-2928. [PMID: 37160706 DOI: 10.1080/07391102.2023.2210674] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/25/2023] [Indexed: 05/11/2023]
Abstract
The main goal of treating any Helicobacter pylori (H. pylori)-related gastrointestinal disease is completely eradicating infection. Falling eradication efficiency, off-target effects, and patient noncompliance with prolonged and broad spectrums have sparked clinical interest in exploring other effective, safer therapeutic choices. As natural substances are risk-free and privileged with high levels of antibacterial activity, most of these natural chemical's specific modes of action are unknown. With the aid of in silico molecular docking-based virtual screening studies and molecular dynamic simulations, the current study is intended to gather data on numerous such natural chemicals and assess their affinity for the S-ribosyl homocysteine lyase (LuxS) protein of H. pylori. The ligand with the highest binding energy with LuxS, glucoraphanin, catechin gallate and epigallocatechin gallate were rationally selected for further computational analysis. The solution stability of the three compounds' optimal docking postures with LuxS was initially assessed using long-run molecular dynamics simulations. Using molecular dynamics simulation, the epigallocatechin gallate was found to be the most stable molecule with the highest binding free energy, indicating that it might compete with the natural ligand of the inhibitors. According to ADMET analysis, his phytochemical was a promising therapeutic candidate for an antibacterial action since it had a range of physicochemical, pharmacokinetic, and drug-like qualities and had no discernible adverse effects. Additional in vitro, in vivo, and clinical trials are needed to confirm the drug's precise efficacy during H. pylori infection.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Avinash Karkada Ashok
- Department of Biotechnology, Siddaganga Institute of Technology, Tumakuru, Karnataka, India
| | - Tamizh Selvan Gnanasekaran
- Central Research Laboratory, KS Hegde Medical Academy, Nitte (Deemed to be University), Mangalore, Karnataka, India
| | | | - Koigoora Srikanth
- Department of Biotechnology, Vignans Foundation for Science, Research and Technology (Deemed to be University), Guntur, Andhra Pradesh, India
| | - Nayana Prakash
- Department of Biotechnology and Bioinformatics, Jnana Sahyadri campus, Kuvempu University, Shankaraghatta, Karnataka, India
| | - Pavan Gollapalli
- Center for Bioinformatics and Biostatistics, Nitte (Deemed to be University), Mangalore, Karnataka, India
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4
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Wang Y, Xu S, He Q, Sun K, Wang X, Zhang X, Li Y, Zeng J. Crosstalk between microbial biofilms in the gastrointestinal tract and chronic mucosa diseases. Front Microbiol 2023; 14:1151552. [PMID: 37125198 PMCID: PMC10133492 DOI: 10.3389/fmicb.2023.1151552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/16/2023] [Indexed: 05/02/2023] Open
Abstract
The gastrointestinal (GI) tract is the largest reservoir of microbiota in the human body; however, it is still challenging to estimate the distribution and life patterns of microbes. Biofilm, as the predominant form in the microbial ecosystem, serves ideally to connect intestinal flora, molecules, and host mucosa cells. It gives bacteria the capacity to inhabit ecological niches, communicate with host cells, and withstand environmental stresses. This study intends to evaluate the connection between GI tract biofilms and chronic mucosa diseases such as chronic gastritis, inflammatory bowel disease, and colorectal cancer. In each disease, we summarize the representative biofilm makers including Helicobacter pylori, adherent-invasive Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. We address biofilm's role in causing inflammation and the pro-carcinogenic stage in addition to discussing the typical resistance, persistence, and recurrence mechanisms seen in vitro. Biofilms may serve as a new biomarker for endoscopic and pathologic detection of gastrointestinal disease and suppression, which may be a useful addition to the present therapy strategy.
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Affiliation(s)
- Yumeng Wang
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Shixi Xu
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Qiurong He
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Kun Sun
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Xiaowan Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Xiaorui Zhang
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
- *Correspondence: Yuqing Li,
| | - Jumei Zeng
- West China-PUMC C.C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Jumei Zeng,
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5
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Interplay between Sulfur Assimilation and Biodesulfurization Activity in Rhodococcus qingshengii IGTS8: Insights into a Regulatory Role of the Reverse Transsulfuration Pathway. mBio 2022; 13:e0075422. [PMID: 35856606 PMCID: PMC9426449 DOI: 10.1128/mbio.00754-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biodesulfurization is a process that selectively removes sulfur from dibenzothiophene and its derivatives. Several natural biocatalysts harboring the highly conserved desulfurization operon dszABC, which is significantly repressed by methionine, cysteine, and inorganic sulfate, have been isolated. However, the available information on the metabolic regulation of gene expression is still limited. In this study, scarless knockouts of the reverse transsulfuration pathway enzyme genes cbs and metB were constructed in the desulfurizing strain Rhodococcus sp. strain IGTS8. We provide sequence analyses and report the enzymes' involvement in the sulfate- and methionine-dependent repression of biodesulfurization activity. Sulfate addition in the bacterial culture did not repress the desulfurization activity of the Δcbs strain, whereas deletion of metB promoted a significant biodesulfurization activity for sulfate-based growth and an even higher desulfurization activity for methionine-grown cells. In contrast, growth on cysteine completely repressed the desulfurization activity of all strains. Transcript level comparison uncovered a positive effect of cbs and metB gene deletions on dsz gene expression in the presence of sulfate and methionine, but not cysteine, offering insights into a critical role of cystathionine β-synthase (CβS) and MetB in desulfurization activity regulation. IMPORTANCE Precise genome editing of the model biocatalyst Rhodococcus qingshengii IGTS8 was performed for the first time, more than 3 decades after its initial discovery. We thus gained insight into the regulation of dsz gene expression and biocatalyst activity, depending on the presence of two reverse transsulfuration enzymes, CβS and MetB. Moreover, we observed an enhancement of biodesulfurization capability in the presence of otherwise repressive sulfur sources, such as sulfate and l-methionine. The interconnection of cellular sulfur assimilation strategies was revealed and validated.
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Kaushik S, Yadav J, Das S, Singh S, Jyoti A, Srivastava VK, Sharma V, Kumar S, Kumar S. Deciphering the Role of S-adenosyl Homocysteine Nucleosidase in Quorum
Sensing Mediated Biofilm Formation. Curr Protein Pept Sci 2022; 23:211-225. [DOI: 10.2174/1389203723666220519152507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/21/2022] [Accepted: 03/11/2022] [Indexed: 11/22/2022]
Abstract
Abstract:
S-adenosylhomocysteine nucleosidase (MTAN) is a protein that plays a crucial role in several
pathways of bacteria that are essential for its survival and pathogenesis. In addition to the role of
MTAN in methyl-transfer reactions, methionine biosynthesis, and polyamine synthesis, MTAN is also
involved in bacterial quorum sensing (QS). In QS, chemical signaling autoinducer (AI) secreted by
bacteria assists cell to cell communication and is regulated in a cell density-dependent manner. They
play a significant role in the formation of bacterial biofilm. MTAN plays a major role in the synthesis
of these autoinducers. Signaling molecules secreted by bacteria, i.e., AI-1 are recognized as acylated
homoserine lactones (AHL) that function as signaling molecules within bacteria. QS enables bacteria
to establish physical interactions leading to biofilm formation. The formation of biofilm is a primary
reason for the development of multidrug-resistant properties in pathogenic bacteria like Enterococcus
faecalis (E. faecalis). In this regard, inhibition of E. faecalis MTAN (EfMTAN) will block the QS and
alter the bacterial biofilm formation. In addition to this, it will also block methionine biosynthesis and
many other critical metabolic processes. It should also be noted that inhibition of EfMTAN will not
have any effect on human beings as this enzyme is not present in humans. This review provides a comprehensive
overview of the structural-functional relationship of MTAN. We have also highlighted the
current status, enigmas that warrant further studies, and the prospects for identifying potential inhibitors
of EfMTAN for the treatment of E. faecalis infections. In addition to this, we have also reported
structural studies of EfMTAN using homology modeling and highlighted the putative binding sites of
the protein.
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Affiliation(s)
- Sanket Kaushik
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Jyoti Yadav
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Satyajeet Das
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
- Structural Biology Lab, CSIR-Institute of Microbial Technology, Chandigarh-160036, India
| | - Suraj Singh
- Centre for Bioseparation Technology, VIT University, Vellore-632014, Tamil Nadu, India
| | - Anupam Jyoti
- Department of Biotechnology, University Institute of Biotechnology, Chandigarh University, Chandigarh, India
| | | | - Vinay Sharma
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Sanjit Kumar
- Centre for Bioseparation Technology, VIT University, Vellore-632014, Tamil Nadu, India
| | - Sujeet Kumar
- Centre for Proteomics and Drug Discovery, Amity Institute of Biotechnology, Amity University, Maharashtra, India
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7
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Buret AG, Allain T, Motta JP, Wallace JL. Effects of Hydrogen Sulfide on the Microbiome: From Toxicity to Therapy. Antioxid Redox Signal 2022; 36:211-219. [PMID: 33691464 PMCID: PMC8861923 DOI: 10.1089/ars.2021.0004] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022]
Abstract
Significance: Hydrogen sulfide (H2S), an important regulator of physiology and health, helps resolve inflammation and promotes tissue repair in the gastrointestinal tract. Recent Advances: Gut microbiota live as a multispecies biofilm in close interaction with the upper mucus layer lining the epithelium. The relative abundance, spatial organization, and function of these microorganisms affect a broad range of health outcomes. This article provides a state-of-the-art review of our understanding of the cross talk between H2S, the gut microbiota, and health. H2S can have toxic or therapeutic effects, depending on its concentration and source. When produced at excessive concentrations by local microbiota, H2S may cause mucus disruption and inflammation and contribute to development of cancer. In contrast, low levels of endogenous or exogenous H2S directly stabilize mucus layers, prevent fragmentation and adherence of the microbiota biofilm to the epithelium, inhibit the release of invasive pathobionts, and help resolve inflammation and tissue injury. Although scarce, research findings suggest that dietary H2S obtained from plants or ingestion of the H2S precursor, L-cysteine, may also modulate the abundance and function of microbiota. Critical Issues: A critical issue is the lack of understanding of the metagenomic, transcriptomic, and proteomic alterations that characterize the interactions between H2S and gut microbiota to shape health outcomes. Future Directions: The ambivalent roles of H2S in the gut offer a fertile ground for research on such critical issues. The findings will improve our understanding of how H2S modulates the microbiota to affect body function and will help identify novel therapeutic strategies. Antioxid. Redox Signal. 36, 211-219.
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Affiliation(s)
- Andre G. Buret
- Host–Parasite Interactions Program, Inflammation Research Network, Biological Sciences, University of Calgary, Calgary, Canada
- Antibe Therapeutics, Inc., Toronto, Canada
| | - Thibault Allain
- Host–Parasite Interactions Program, Inflammation Research Network, Biological Sciences, University of Calgary, Calgary, Canada
| | - Jean-Paul Motta
- Institute of Digestive Health Research, IRSD, INSERM U1220, Toulouse, France
| | - John L. Wallace
- Host–Parasite Interactions Program, Inflammation Research Network, Biological Sciences, University of Calgary, Calgary, Canada
- Antibe Therapeutics, Inc., Toronto, Canada
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8
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de Almeida OGG, Vitulo N, De Martinis ECP, Felis GE. Pangenome analyses of LuxS-coding genes and enzymatic repertoires in cocoa-related lactic acid bacteria. Genomics 2021; 113:1659-1670. [PMID: 33839269 DOI: 10.1016/j.ygeno.2021.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/04/2021] [Accepted: 04/05/2021] [Indexed: 01/15/2023]
Abstract
Lactobacillaceae presents potential for interspecific Quorum Sensing (QS) in spontaneous cocoa fermentation, correlated with high abundance of luxS. Three Brazilian isolates from cocoa fermentation were characterized by Whole Genome Sequencing and luxS gene was surveyed in their genomes, in comparison with public databases. They were classified as Lactiplantibacillus plantarum, Limosilactobacillus fermentum and Pediococcus acidilactici. LuxS genes were conserved in core genomes of the novel isolates, but in some non-cocoa related Lactic Acid Bacteria (LAB) it was accessory and plasmid-borne. The conservation and horizontal acquisition of luxS reinforces that QS is determinant for bacterial adaptation in several environments, especially taking into account the luxS has been correlated with modulation of bacteriocin production, stress tolerance and biofilm formation. Therefore, in this paper, new clade and species-specific primers were designed for future application for screening of luxS gene in LAB to evaluate the adaptive potential to diverse food fermentations.
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Affiliation(s)
| | - Nicola Vitulo
- University of Verona, Department of Biotechnology, Verona, Italy
| | | | - Giovanna E Felis
- University of Verona, Department of Biotechnology, Verona, Italy
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9
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Wen Y, Huang H, Tang T, Yang H, Wang X, Huang X, Gong Y, Zhang X, She F. AI-2 represses CagA expression and bacterial adhesion, attenuating the Helicobacter pylori-induced inflammatory response of gastric epithelial cells. Helicobacter 2021; 26:e12778. [PMID: 33400843 DOI: 10.1111/hel.12778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Helicobacter pylori (H. pylori) infection of gastric epithelial cells induces inflammatory response. Outer membrane proteins (OMPs), Type 4 secretion system (T4SS) encoded by cagPAI, and the effector protein CagA are involved in the pathogenesis of H. pylori. H. pylori possesses a gene encoding LuxS which synthesizes AI-2, a quorum sensing signal molecule. The aim of this study was to investigate the role of AI-2 in the expression of virulence factors and the inflammatory response of gastric epithelial (AGS) cells induced by H. pylori. MATERIALS AND METHODS H. pylori ΔluxS mutant was constructed, and AI-2 activity was measured with Vibrio harveyi BB170. NF-κB activation, IL-8 production, expression of OMPs (outer membrane proteins), CagA, and T4SS encoded by cagPAI were investigated in H. pylori wild type, and ΔluxS with or without supplementation of AI-2. RESULTS H. pylori produced approximately 7 μM of AI-2 in the medium. AI-2 inhibited expression and translocation of CagA after infection of AGS cells. AI-2 upregulated the expression of CagM, CagE, and CagX, while had no effect to the interaction between T4SS and α5β1 integrin. AI-2 also reduced expression of adhesins and bacterial adhesion to AGS cells. Finally, AI-2 reduced the activation of NF-κB and expression of IL-8 in H. pylori-infected AGS. CONCLUSIONS AI-2 plays an important role in the pathogenesis of H. pylori. AI-2 inhibits the bacterial adhesion, expression, and translocation of CagA, and attenuates the inflammatory response of AGS cells induced by H. pylori.
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Affiliation(s)
- Yancheng Wen
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Hongming Huang
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Tiechen Tang
- The First Hospital of Nanping City, affiliated to Fujian Medical University, Nanping, Fujian, China
| | - Huang Yang
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xi Wang
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xi Huang
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Yingying Gong
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xiaoyan Zhang
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Feifei She
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
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10
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Wada M, Fukiya S, Suzuki A, Matsumoto N, Matsuo M, Yokota A. Methionine utilization by bifidobacteria: possible existence of a reverse transsulfuration pathway. BIOSCIENCE OF MICROBIOTA FOOD AND HEALTH 2021; 40:80-83. [PMID: 33520573 PMCID: PMC7817509 DOI: 10.12938/bmfh.2020-031] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 08/07/2020] [Indexed: 01/04/2023]
Abstract
Although bifidobacteria are already widely used as beneficial microbes with
health-promoting effects, their amino acid utilization and metabolism are not yet fully
understood. Knowledge about the metabolism of sulfur-containing amino acids in
bifidobacteria is especially limited. In this study, we tested the methionine utilization
ability of several bifidobacterial strains when it was the sole available sulfur source.
Although bifidobacteria have long been predominantly considered to be cysteine auxotrophs,
we showed that this is not necessarily the case.
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Affiliation(s)
- Masaru Wada
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan.,Present address: Faculty of Agriculture, Setsunan University, 45-1 Nagaotouge-cho, Hirakata-shi, Osaka 573-0101, Japan
| | - Satoru Fukiya
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Azusa Suzuki
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Nanae Matsumoto
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Miki Matsuo
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Atsushi Yokota
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
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The Role of luxS in Histophilus somni Virulence and Biofilm Formation. Infect Immun 2021; 89:IAI.00567-20. [PMID: 33139386 DOI: 10.1128/iai.00567-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 10/29/2020] [Indexed: 01/09/2023] Open
Abstract
S-Ribosylhomocysteinase (LuxS) is required for the synthesis of the autoinducer-2 (AI-2) quorum-sensing signaling molecule in many Gram-negative bacteria. The bovine (and ovine) opportunistic pathogen Histophilus somni contains luxS and forms a biofilm containing an exopolysaccharide (EPS) in the matrix. Since biofilm formation is regulated by quorum sensing in many bacteria, the roles of luxS in H. somni virulence and biofilm formation were investigated. Although culture supernatants from H. somni were ineffective at inducing bioluminescence in the Vibrio harveyi reporter strain BB170, H. somni luxS complemented the biosynthesis of AI-2 in the luxS-deficient Escherichia coli strain DH5α. H. somni strain 2336 luxS was inactivated by transposon mutagenesis. RNA expression profiles revealed that many genes were significantly differentially expressed in the luxS mutant compared to that in the wild-type, whether the bacteria were grown planktonically or in a biofilm. Furthermore, the luxS mutant had a truncated and asialylated lipooligosaccharide (LOS) and was substantially more serum sensitive than the wild-type. Not surprisingly, the luxS mutant was attenuated in a mouse model for H. somni virulence, and some of the altered phenotypes were partially restored after the mutation was complemented with a functional luxS However, no major differences were observed between the wild-type and the luxS mutant in regard to outer membrane protein profiles, biofilm formation, EPS production, or intracellular survival. These results indicate that luxS plays a role in H. somni virulence in the context of LOS biosynthesis but not biofilm formation or other phenotypic properties examined.
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Matoba Y, Noda M, Yoshida T, Oda K, Ezumi Y, Yasutake C, Izuhara-Kihara H, Danshiitsoodol N, Kumagai T, Sugiyama M. Catalytic specificity of the Lactobacillus plantarum cystathionine γ-lyase presumed by the crystallographic analysis. Sci Rep 2020; 10:14886. [PMID: 32913258 DOI: 10.1038/s51598-020-71756-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/05/2020] [Indexed: 05/22/2023] Open
Abstract
The reverse transsulfuration pathway, which is composed of cystathionine β-synthase (CBS) and cystathionine γ-lyase (CGL), plays a role to synthesize L-cysteine using L-serine and the sulfur atom in L-methionine. A plant-derived lactic acid bacterium Lactobacillus plantarum SN35N has been previously found to harbor the gene cluster encoding the CBS- and CGL-like enzymes. In addition, it has been demonstrated that the L. plantarum CBS can synthesize cystathionine from O-acetyl-L-serine and L-homocysteine. The aim of this study is to characterize the enzymatic functions of the L. plantarum CGL. We have found that the enzyme has the high γ-lyase activity toward cystathionine to generate L-cysteine, together with the β-lyase activity toward L-cystine to generate L-cysteine persulfide. By the crystallographic analysis of the inactive CGL K194A mutant complexed with cystathionine, we have found the residues which recognize the distal amino and carboxyl groups of cystathionine or L-cystine. The PLP-bound substrates at the active site may take either the binding pose for the γ- or β-elimination reaction, with the former being the major reaction in the case of cystathionine.
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Affiliation(s)
- Yasuyuki Matoba
- Faculty of Pharmacy, Yasuda Women's University, Yasuhigashi 6-13-1, Asaminami-ku, Hiroshima, 731-0153, Japan.
| | - Masafumi Noda
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Tomoki Yoshida
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kosuke Oda
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Yuka Ezumi
- Faculty of Pharmacy, Yasuda Women's University, Yasuhigashi 6-13-1, Asaminami-ku, Hiroshima, 731-0153, Japan
| | - Chiaki Yasutake
- Faculty of Pharmaceutical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Hisae Izuhara-Kihara
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Narandarai Danshiitsoodol
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Takanori Kumagai
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Masanori Sugiyama
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan.
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Catalytic specificity of the Lactobacillus plantarum cystathionine γ-lyase presumed by the crystallographic analysis. Sci Rep 2020; 10:14886. [PMID: 32913258 PMCID: PMC7483736 DOI: 10.1038/s41598-020-71756-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/05/2020] [Indexed: 11/17/2022] Open
Abstract
The reverse transsulfuration pathway, which is composed of cystathionine β-synthase (CBS) and cystathionine γ-lyase (CGL), plays a role to synthesize l-cysteine using l-serine and the sulfur atom in l-methionine. A plant-derived lactic acid bacterium Lactobacillus plantarum SN35N has been previously found to harbor the gene cluster encoding the CBS- and CGL-like enzymes. In addition, it has been demonstrated that the L. plantarum CBS can synthesize cystathionine from O-acetyl-l-serine and l-homocysteine. The aim of this study is to characterize the enzymatic functions of the L. plantarum CGL. We have found that the enzyme has the high γ-lyase activity toward cystathionine to generate l-cysteine, together with the β-lyase activity toward l-cystine to generate l-cysteine persulfide. By the crystallographic analysis of the inactive CGL K194A mutant complexed with cystathionine, we have found the residues which recognize the distal amino and carboxyl groups of cystathionine or l-cystine. The PLP-bound substrates at the active site may take either the binding pose for the γ- or β-elimination reaction, with the former being the major reaction in the case of cystathionine.
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14
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Bacterial Pathogens Hijack the Innate Immune Response by Activation of the Reverse Transsulfuration Pathway. mBio 2019; 10:mBio.02174-19. [PMID: 31662455 PMCID: PMC6819659 DOI: 10.1128/mbio.02174-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Macrophages are professional immune cells that ingest and kill microbes. In this study, we show that different pathogenic bacteria induce the expression of cystathionine γ-lyase (CTH) in macrophages. This enzyme is involved in a metabolic pathway called the reverse transsulfuration pathway, which leads to the production of numerous metabolites, including cystathionine. Phagocytized bacteria use cystathionine to better survive in macrophages. In addition, the induction of CTH results in dysregulation of the metabolism of polyamines, which in turn dampens the proinflammatory response of macrophages. In conclusion, pathogenic bacteria can evade the host immune response by inducing CTH in macrophages. The reverse transsulfuration pathway is the major route for the metabolism of sulfur-containing amino acids. The role of this metabolic pathway in macrophage response and function is unknown. We show that the enzyme cystathionine γ-lyase (CTH) is induced in macrophages infected with pathogenic bacteria through signaling involving phosphatidylinositol 3-kinase (PI3K)/MTOR and the transcription factor SP1. This results in the synthesis of cystathionine, which facilitates the survival of pathogens within myeloid cells. Our data demonstrate that the expression of CTH leads to defective macrophage activation by (i) dysregulation of polyamine metabolism by depletion of S-adenosylmethionine, resulting in immunosuppressive putrescine accumulation and inhibition of spermidine and spermine synthesis, and (ii) increased histone H3K9, H3K27, and H3K36 di/trimethylation, which is associated with gene expression silencing. Thus, CTH is a pivotal enzyme of the innate immune response that disrupts host defense. The induction of the reverse transsulfuration pathway by bacterial pathogens can be considered an unrecognized mechanism for immune escape.
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Devi S, Tarique KF, Ali MF, Abdul Rehman SA, Gourinath S. Identification and characterization of Helicobacter pylori O-acetylserine-dependent cystathionine β-synthase, a distinct member of the PLP-II family. Mol Microbiol 2019; 112:718-739. [PMID: 31132312 DOI: 10.1111/mmi.14315] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2019] [Indexed: 02/02/2023]
Abstract
O-acetylserine sulfhydrylase (OASS) and cystathionine β-synthase (CBS) are members of the PLP-II family, and involved in L-cysteine production. OASS produces L-cysteine via a de novo pathway while CBS participates in the reverse transsulfuration pathway. O-acetylserine-dependent CBS (OCBS) was previously identified as a new member of the PLP-II family, which are predominantly seen in bacteria. The bacterium Helicobacter pylori possess only one OASS (hp0107) gene and we showed that the protein coded by this gene actually functions as an OCBS and utilizes L-homocysteine and O-acetylserine (OAS) to produce cystathionine. HpOCBS did not show CBS activity with the substrate L-serine and required OAS exclusively. The HpOCBS structure in complex with methionine showed a closed cleft state, explaining the initial mode of substrate binding. Sequence and structural analyses showed differences between the active sites of OCBS and CBS, and explain their different substrate preferences. We identified three hydrophobic residues near the active site of OCBS, corresponding to one serine and two tyrosine residues in CBSs. Mutational studies were performed on HpOCBS and Saccharomyces cerevisiae CBS. A ScCBS double mutant (Y158F/Y226V) did not display activity with L-serine, indicating indispensability of these polar residues for selecting substrate L-serine, however, did show activity with OAS.
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Affiliation(s)
- Suneeta Devi
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Khaja Faisal Tarique
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.,Public Health Research Institute, Rutgers, Newark, NJ, USA
| | - Mohammad Farhan Ali
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Syed Arif Abdul Rehman
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.,MRC Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Samudrala Gourinath
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
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16
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Rizzato C, Torres J, Kasamatsu E, Camorlinga-Ponce M, Bravo MM, Canzian F, Kato I. Potential Role of Biofilm Formation in the Development of Digestive Tract Cancer With Special Reference to Helicobacter pylori Infection. Front Microbiol 2019; 10:846. [PMID: 31110496 PMCID: PMC6501431 DOI: 10.3389/fmicb.2019.00846] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/02/2019] [Indexed: 12/16/2022] Open
Abstract
Bacteria are highly social organisms that communicate via signaling molecules and can assume a multicellular lifestyle to build biofilm communities. Until recently, complications from biofilm-associated infection have been primarily ascribed to increased bacterial resistance to antibiotics and host immune evasion, leading to persistent infection. In this theory and hypothesis article we present a relatively new argument that biofilm formation has potential etiological role in the development of digestive tract cancer. First, we summarize recent new findings suggesting the potential link between bacterial biofilm and various types of cancer to build the foundation of our hypothesis. To date, evidence has been particularly convincing for colorectal cancer and its precursor, i.e., polyps, pointing to several key individual bacterial species, such as Bacteroides fragilis, Fusobacterium nucleatum, and Streptococcus gallolyticus subsp. Gallolyticus. Then, we further extend this hypothesis to one of the most common bacterial infection in humans, Helicobacter pylori (Hp), which is considered a major cause of gastric cancer. Thus far, there has been no direct evidence linking in vivo Hp gastric biofilm formation to gastric carcinogenesis. Yet, we synthesize the information to support an argument that biofilm associated-Hp is potentially more carcinogenic, summarizing biological characteristics of biofilm-associated bacteria. We also discuss mechanistic pathways as to how Hp or other biofilm-associated bacteria control biofilm formation and highlight recent findings on Hp genes that influence biofilm formation, which may lead to strain variability in biofilm formation. This knowledge may open a possibility of developing targeted intervention. We conclude, however, that this field is still in its infancy. To test the hypothesis rigorously and to link it ultimately to gastric pathologies (e.g., premalignant lesions and cancer), studies are needed to learn more about Hp biofilms, such as compositions and biological properties of extracellular polymeric substance (EPS), presence of non-Hp microbiome and geographical distribution of biofilms in relation to gastric gland types and structures. Identification of specific Hp strains with enhanced biofilm formation would be helpful not only for screening patients at high risk for sequelae from Hp infection, but also for development of new antibiotics to avoid resistance, regardless of its association with gastric cancer.
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Affiliation(s)
- Cosmeri Rizzato
- Department of Translation Research and of New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Javier Torres
- Unidad de Investigación en Enfermedades Infecciosas, Unidades Médicas de Alta Especialidad Pediatría, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Elena Kasamatsu
- Instituto de Investigaciones en Ciencias de la Salud, National University of Asunción, Asunción, Paraguay
| | - Margarita Camorlinga-Ponce
- Unidad de Investigación en Enfermedades Infecciosas, Unidades Médicas de Alta Especialidad Pediatría, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Maria Mercedes Bravo
- Grupo de Investigación en Biología del Cáncer, Instituto Nacional de Cancerología, Bogotá, Colombia
| | - Federico Canzian
- Genomic Epidemiology Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ikuko Kato
- Department of Oncology and Pathology, Wayne State University School of Medicine, Detroit, MI, United States
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17
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Mechanisms of Bacterial Tolerance and Persistence in the Gastrointestinal and Respiratory Environments. Clin Microbiol Rev 2018; 31:31/4/e00023-18. [PMID: 30068737 DOI: 10.1128/cmr.00023-18] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as Escherichia coli, Salmonella spp., Vibrio spp., Helicobacter spp., Campylobacter jejuni, Enterococcus spp., Shigella spp., Yersinia spp., and Clostridium difficile, all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cenocepacia, and Mycobacterium tuberculosis Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.
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18
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Matoba Y, Yoshida T, Izuhara-Kihara H, Noda M, Sugiyama M. Crystallographic and mutational analyses of cystathionine β-synthase in the H 2 S-synthetic gene cluster in Lactobacillus plantarum. Protein Sci 2017; 26:763-783. [PMID: 28127810 DOI: 10.1002/pro.3123] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/10/2017] [Accepted: 01/17/2017] [Indexed: 11/05/2022]
Abstract
Cystathionine β-synthase (CBS) catalyzes the formation of l-cystathionine from l-serine and l-homocysteine. The resulting l-cystathionine is decomposed into l-cysteine, ammonia, and α-ketobutylic acid by cystathionine γ-lyase (CGL). This reverse transsulfuration pathway, which is catalyzed by both enzymes, mainly occurs in eukaryotic cells. The eukaryotic CBS and CGL have recently been recognized as major physiological enzymes for the generation of hydrogen sulfide (H2 S). In some bacteria, including the plant-derived lactic acid bacterium Lactobacillus plantarum, the CBS- and CGL-encoding genes form a cluster in their genomes. Inactivation of these enzymes has been reported to suppress H2 S production in bacteria; interestingly, it has been shown that H2 S suppression increases their susceptibility to various antibiotics. In the present study, we characterized the enzymatic properties of the L. plantarum CBS, whose amino acid sequence displays a similarity with those of O-acetyl-l-serine sulfhydrylase (OASS) that catalyzes the generation of l-cysteine from O-acetyl-l-serine (l-OAS) and H2 S. The L. plantarum CBS shows l-OAS- and l-cysteine-dependent CBS activities together with OASS activity. Especially, it catalyzes the formation of H2 S in the presence of l-cysteine and l-homocysteine, together with the formation of l-cystathionine. The high affinity toward l-cysteine as a first substrate and tendency to use l-homocysteine as a second substrate might be associated with its enzymatic ability to generate H2 S. Crystallographic and mutational analyses of CBS indicate that the Ala70 and Glu223 residues at the substrate binding pocket are important for the H2 S-generating activity.
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Affiliation(s)
- Yasuyuki Matoba
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Tomoki Yoshida
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Hisae Izuhara-Kihara
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Masafumi Noda
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Masanori Sugiyama
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
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19
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The fitness burden imposed by synthesising quorum sensing signals. Sci Rep 2016; 6:33101. [PMID: 27616328 PMCID: PMC5018880 DOI: 10.1038/srep33101] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/12/2016] [Indexed: 12/20/2022] Open
Abstract
It is now well established that bacterial populations utilize cell-to-cell signaling (quorum-sensing, QS) to control the production of public goods and other co-operative behaviours. Evolutionary theory predicts that both the cost of signal production and the response to signals should incur fitness costs for producing cells. Although costs imposed by the downstream consequences of QS have been shown, the cost of QS signal molecule (QSSM) production and its impact on fitness has not been examined. We measured the fitness cost to cells of synthesising QSSMs by quantifying metabolite levels in the presence of QSSM synthases. We found that: (i) bacteria making certain QSSMs have a growth defect that exerts an evolutionary cost, (ii) production of QSSMs negatively correlates with intracellular concentrations of QSSM precursors, (iii) the production of heterologous QSSMs negatively impacts the production of a native QSSM that shares common substrates, and (iv) supplementation with exogenously added metabolites partially rescued growth defects imposed by QSSM synthesis. These data identify the sources of the fitness costs incurred by QSSM producer cells, and indicate that there may be metabolic trade-offs associated with QS signaling that could exert selection on how signaling evolves.
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Yonezawa H, Osaki T, Kamiya S. Biofilm Formation by Helicobacter pylori and Its Involvement for Antibiotic Resistance. BIOMED RESEARCH INTERNATIONAL 2015; 2015:914791. [PMID: 26078970 PMCID: PMC4452508 DOI: 10.1155/2015/914791] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/25/2014] [Indexed: 12/12/2022]
Abstract
Bacterial biofilms are communities of microorganisms attached to a surface. Biofilm formation is critical not only for environmental survival but also for successful infection. Helicobacter pylori is one of the most common causes of bacterial infection in humans. Some studies demonstrated that this microorganism has biofilm forming ability in the environment and on human gastric mucosa epithelium as well as on in vitro abiotic surfaces. In the environment, H. pylori could be embedded in drinking water biofilms through water distribution system in developed and developing countries so that the drinking water may serve as a reservoir for H. pylori infection. In the human stomach, H. pylori forms biofilms on the surface of gastric mucosa, suggesting one possible explanation for eradication therapy failure. Finally, based on the results of in vitro analyses, H. pylori biofilm formation can decrease susceptibility to antibiotics and H. pylori antibiotic resistance mutations are more frequently generated in biofilms than in planktonic cells. These observations indicated that H. pylori biofilm formation may play an important role in preventing and controlling H. pylori infections. Therefore, investigation of H. pylori biofilm formation could be effective in elucidating the detailed mechanisms of infection and colonization by this microorganism.
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Affiliation(s)
- Hideo Yonezawa
- Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
| | - Takako Osaki
- Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
| | - Shigeru Kamiya
- Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
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21
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Pérez-Rodríguez I, Bolognini M, Ricci J, Bini E, Vetriani C. From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria. ISME JOURNAL 2014; 9:1222-34. [PMID: 25397946 DOI: 10.1038/ismej.2014.214] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 09/27/2014] [Accepted: 10/01/2014] [Indexed: 12/27/2022]
Abstract
Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed--and a quorum-sensing signal is produced--during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens.
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Affiliation(s)
- Ileana Pérez-Rodríguez
- 1] Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA [2] Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Marie Bolognini
- 1] Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA [2] Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Jessica Ricci
- 1] Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA [2] Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Elisabetta Bini
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA
| | - Costantino Vetriani
- 1] Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, USA [2] Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
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22
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Cho K, Evans BS, Wood BM, Kumar R, Erb TJ, Warlick BP, Gerlt JA, Sweedler JV. Integration of untargeted metabolomics with transcriptomics reveals active metabolic pathways. Metabolomics 2014; 2014. [PMID: 25705145 PMCID: PMC4334135 DOI: 10.1007/s11306-014-0713-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
While recent advances in metabolomic measurement technologies have been dramatic, extracting biological insight from complex metabolite profiles remains a challenge. We present an analytical strategy that uses data obtained from high resolution liquid chromatography-mass spectrometry and a bioinformatics toolset for detecting actively changing metabolic pathways upon external perturbation. We begin with untargeted metabolite profiling to nominate altered metabolites and identify pathway candidates, followed by validation of those pathways with transcriptomics. Using the model organisms Rhodospirillum rubrum and Bacillus subtilis, our results reveal metabolic pathways that are interconnected with methionine salvage. The rubrum-type methionine salvage pathway is interconnected with the active methyl cycle in which re-methylation, a key reaction for recycling methionine from homocysteine, is unexpectedly suppressed; instead, homocysteine is catabolized by the transsulfuration pathway. Notably, the non-mevalonate pathway is repressed, whereas the rubrum-type methionine salvage pathway contributes to isoprenoid biosynthesis upon 5'-methylthioadenosine feeding. In this process, glutathione functions as a coenzyme in vivo when 1-methylthio-d-xylulose 5-phosphate (MTXu 5-P) methylsulfurylase catalyzes dethiomethylation of MTXu 5-P. These results clearly show that our analytical approach enables unexpected metabolic pathways to be uncovered.
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Affiliation(s)
- Kyuil Cho
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 USA
| | - Bradley S. Evans
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 USA
| | - B. McKay Wood
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Ritesh Kumar
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Tobias J. Erb
- Institute for Microbiology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8093 Zurich, Switzerland
| | - Benjamin P. Warlick
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - John A. Gerlt
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Jonathan V. Sweedler
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 USA
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Vorwerk H, Mohr J, Huber C, Wensel O, Schmidt-Hohagen K, Gripp E, Josenhans C, Schomburg D, Eisenreich W, Hofreuter D. Utilization of host-derived cysteine-containing peptides overcomes the restricted sulphur metabolism of Campylobacter jejuni. Mol Microbiol 2014; 93:1224-45. [PMID: 25074326 DOI: 10.1111/mmi.12732] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2014] [Indexed: 12/12/2022]
Abstract
The non-glycolytic food-borne pathogen Campylobacter jejuni successfully colonizes the intestine of various hosts in spite of its restricted metabolic properties. While several amino acids are known to be used by C. jejuni as energy sources, none of these have been found to be essential for growth. Here we demonstrated through phenotype microarray analysis that cysteine utilization increases the metabolic activity of C. jejuni. Furthermore, cysteine was crucial for its growth as C. jejuni was unable to synthesize it from sulphate or methionine. Our study showed that C. jejuni compensates this limited anabolic capacity by utilizing sulphide, thiosulphate, glutathione and the dipeptides γGlu-Cys, Cys-Gly and Gly-Cys as sulphur sources and cysteine precursors. A panel of C. jejuni mutants in putative peptidases and peptide transporters were generated and tested for their participation in the catabolism of the cysteine-containing peptides, and the predicted transporter protein CJJ81176_0236 was discovered to facilitate the growth with the dipeptide Cys-Gly, Ile-Arg and Ile-Trp. It was named Campylobacter peptide transporter A (CptA) and is the first representative of the oligopeptide transporter OPT family demonstrated to participate in the glutathione-derivative Cys-Gly catabolism in prokaryotes. Our study provides new insights into how host- and microbiota-derived substrates like sulphide, thiosulphate and short peptides are used by C. jejuni to compensate its restricted metabolic capacities.
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Affiliation(s)
- Hanne Vorwerk
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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24
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Haigh R, Kumar B, Sandrini S, Freestone P. Mutation design and strain background influence the phenotype ofEscherichia coli luxSmutants. Mol Microbiol 2013; 88:951-69. [DOI: 10.1111/mmi.12237] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Richard Haigh
- Department of Genetics; University of Leicester; Leicester UK
| | - Brijesh Kumar
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
| | - Sara Sandrini
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
| | - Primrose Freestone
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
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25
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Pereira CS, Thompson JA, Xavier KB. AI-2-mediated signalling in bacteria. FEMS Microbiol Rev 2012; 37:156-81. [PMID: 22712853 DOI: 10.1111/j.1574-6976.2012.00345.x] [Citation(s) in RCA: 355] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/06/2012] [Accepted: 06/08/2012] [Indexed: 02/06/2023] Open
Abstract
Success in nature depends upon an ability to perceive and adapt to the surrounding environment. Bacteria are not an exception; they recognize and constantly adjust to changing situations by sensing environmental and self-produced signals, altering gene expression accordingly. Autoinducer-2 (AI-2) is a signal molecule produced by LuxS, an enzyme found in many bacterial species and thus proposed to enable interspecies communication. Two classes of AI-2 receptors and many layers and interactions involved in downstream signalling have been identified so far. Although AI-2 has been implicated in the regulation of numerous niche-specific behaviours across the bacterial kingdom, interpretation of these results is complicated by the dual role of LuxS in signalling and the activated methyl cycle, a crucial central metabolic pathway. In this article, we present a comprehensive review of the discovery and early characterization of AI-2, current developments in signal detection, transduction and regulation, and the major studies investigating the phenotypes regulated by this molecule. The development of novel tools should help to resolve many of the remaining questions in the field; we highlight how these advances might be exploited in AI-2 quorum quenching, treatment of diseases, and the manipulation of beneficial behaviours caused by polyspecies communities.
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26
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Gölz G, Sharbati S, Backert S, Alter T. Quorum sensing dependent phenotypes and their molecular mechanisms in Campylobacterales. Eur J Microbiol Immunol (Bp) 2012; 2:50-60. [PMID: 24611121 DOI: 10.1556/eujmi.2.2012.1.8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 01/06/2012] [Indexed: 12/26/2022] Open
Abstract
Quorum sensing comprises the mechanism of communication between numerous bacteria via small signalling molecules, termed autoinducers (AI). Using quorum sensing, bacteria can regulate the expression of multiple genes involved in virulence, toxin production, motility, chemotaxis and biofilm formation, thus contributing to adaptation as well as colonisation. The current understanding of the role of quorum sensing in the lifecycle of Campylobacterales is still incomplete. Campylobacterales belong to the class of Epsilonproteobacteria representing a physiologically and ecologically diverse group of bacteria that are rather distinct from the more commonly studied Proteobacteria, such as Escherichia and Salmonella. This review summarises the recent knowledge on distribution and production of AI molecules, as well as possible quorum sensing dependent regulation in the mostly investigated species within the Campylobacterales group: Campylobacter jejuni and Helicobacter pylori.
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27
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Rader BA, Wreden C, Hicks KG, Sweeney EG, Ottemann KM, Guillemin K. Helicobacter pylori perceives the quorum-sensing molecule AI-2 as a chemorepellent via the chemoreceptor TlpB. MICROBIOLOGY-SGM 2011; 157:2445-2455. [PMID: 21602215 DOI: 10.1099/mic.0.049353-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Helicobacter pylori moves in response to environmental chemical cues using a chemotaxis two-component signal-transduction system. Autoinducer-2 (AI-2) is a quorum-sensing signal produced by the LuxS protein that accumulates in the bacterial environment in a density-dependent manner. We showed previously that a H. pylori luxS mutant was defective in motility on soft agar plates. Here we report that deletion of the luxS gene resulted in swimming behaviour with a reduced frequency of stops as compared to the wild-type strain. Stopping frequency was restored to wild-type levels by genetic complementation of the luxS mutation or by addition of synthetic 4,5-dihydroxy-2,3-pentanedione (DPD), which cyclizes to form AI-2. Synthetic DPD also increased the frequency of stops in wild-type H. pylori, similar to the behaviour induced by the known chemorepellent HCl. We found that whereas mutants lacking the chemoreceptor genes tlpA, tlpC or tlpD responded to an exogenous source of synthetic DPD, the chemoreceptor mutant tlpB was non-responsive to a gradient or uniform distribution of the chemical. Furthermore, a double mutant lacking both tlpB and luxS exhibited chemotactic behaviour similar to the tlpB single mutant, whereas a double mutant lacking both tlpB and the chemotransduction gene cheA behaved like a nonchemotactic cheA single mutant, supporting the model that tlpB functions in a signalling pathway downstream of luxS and upstream of cheA. We conclude that H. pylori perceives LuxS-produced AI-2 as a chemorepellent via the chemoreceptor TlpB.
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Affiliation(s)
- Bethany A Rader
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Christopher Wreden
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Kevin G Hicks
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | | | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
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Parveen N, Cornell KA. Methylthioadenosine/S-adenosylhomocysteine nucleosidase, a critical enzyme for bacterial metabolism. Mol Microbiol 2010; 79:7-20. [PMID: 21166890 DOI: 10.1111/j.1365-2958.2010.07455.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The importance of methylthioadenosine/S-adenosylhomocysteine (MTA/SAH) nucleosidase in bacteria has started to be appreciated only in the past decade. A comprehensive analysis of its various roles here demonstrates that it is an integral component of the activated methyl cycle, which recycles adenine and methionine through S-adenosylmethionine (SAM)-mediated methylation reactions, and also produces the universal quorum-sensing signal, autoinducer-2 (AI-2). SAM is also essential for synthesis of polyamines, N-acylhomoserine lactone (autoinducer-1), and production of vitamins and other biomolecules formed by SAM radical reactions. MTA, SAH and 5'-deoxyadenosine (5'dADO) are product inhibitors of these reactions, and are substrates of MTA/SAH nucleosidase, underscoring its importance in a wide array of metabolic reactions. Inhibition of this enzyme by certain substrate analogues also limits synthesis of autoinducers and hence causes reduction in biofilm formation and may attenuate virulence. Interestingly, the inhibitors of MTA/SAH nucleosidase are very effective against the Lyme disease causing spirochaete, Borrelia burgdorferi, which uniquely expresses three homologous functional enzymes. These results indicate that inhibition of this enzyme can affect growth of different bacteria by affecting different mechanisms. Therefore, new inhibitors are currently being explored for development of potential novel broad-spectrum antimicrobials.
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Affiliation(s)
- Nikhat Parveen
- Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 225 Warren Street, Newark, NJ 07103-3535, USA.
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29
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In Helicobacter pylori auto-inducer-2, but not LuxS/MccAB catalysed reverse transsulphuration, regulates motility through modulation of flagellar gene transcription. BMC Microbiol 2010; 10:210. [PMID: 20691071 PMCID: PMC2923134 DOI: 10.1186/1471-2180-10-210] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 08/06/2010] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND LuxS may function as a metabolic enzyme or as the synthase of a quorum sensing signalling molecule, auto-inducer-2 (AI-2); hence, the mechanism underlying phenotypic changes upon luxS inactivation is not always clear. In Helicobacter pylori, we have recently shown that, rather than functioning in recycling methionine as in most bacteria, LuxS (along with newly-characterised MccA and MccB), synthesises cysteine via reverse transsulphuration. In this study, we investigated whether and how LuxS controls motility of H. pylori, specifically if it has its effects via luxS-required cysteine metabolism or via AI-2 synthesis only. RESULTS We report that disruption of luxS renders H. pylori non-motile in soft agar and by microscopy, whereas disruption of mccAHp or mccBHp (other genes in the cysteine provision pathway) does not, implying that the lost phenotype is not due to disrupted cysteine provision. The motility defect of the DeltaluxSHp mutant was complemented genetically by luxSHp and also by addition of in vitro synthesised AI-2 or 4, 5-dihydroxy-2, 3-pentanedione (DPD, the precursor of AI-2). In contrast, exogenously added cysteine could not restore motility to the DeltaluxSHp mutant, confirming that AI-2 synthesis, but not the metabolic effect of LuxS was important. Microscopy showed reduced number and length of flagella in the DeltaluxSHp mutant. Immunoblotting identified decreased levels of FlaA and FlgE but not FlaB in the DeltaluxSHp mutant, and RT-PCR showed that the expression of flaA, flgE, motA, motB, flhA and fliI but not flaB was reduced. Addition of DPD but not cysteine to the DeltaluxSHp mutant restored flagellar gene transcription, and the number and length of flagella. CONCLUSIONS Our data show that as well as being a metabolic enzyme, H. pylori LuxS has an alternative role in regulation of motility by modulating flagellar transcripts and flagellar biosynthesis through production of the signalling molecule AI-2.
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Halliday NM, Hardie KR, Williams P, Winzer K, Barrett DA. Quantitative liquid chromatography-tandem mass spectrometry profiling of activated methyl cycle metabolites involved in LuxS-dependent quorum sensing in Escherichia coli. Anal Biochem 2010; 403:20-9. [PMID: 20417170 DOI: 10.1016/j.ab.2010.04.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 04/16/2010] [Accepted: 04/17/2010] [Indexed: 10/19/2022]
Abstract
A rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry assay has been developed and validated for the simultaneous quantification of the metabolites and precursors of the activated methyl cycle, reported in preliminary form by Heurlier et al. (2009) [43]. Analytes were extracted from Escherichia coli MG1655 and chemically derivatized as N(O,S)-iso-butyloxycarbonyl iso-butyl esters using iso-butyl chloroformate in an aqueous iso-butanol/pyridine environment. S-Adenosylmethionine, S-adenosylhomocysteine, S-ribosylhomocysteine, homocysteine, methionine, cystathionine, cysteine, and homoserine were quantified by liquid chromatography-positive ion tandem electrospray ionization mass spectrometry. Internal standards were isotopically labeled [(13)CD(3)]methionine and S-adenosylcysteine. Linearity of the assay was established up to a concentration of 700 microg/g cell dry weight for each analyte. The validated assay was used to quantitatively profile the intracellular activated methyl cycle metabolites as a function of growth in E. coli MG1655 and its derivative Deltapfs and DeltaluxS mutants to determine the metabolic consequences of a disruption to the activated methyl cycle and, hence, LuxS-dependent quorum sensing.
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Affiliation(s)
- N M Halliday
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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