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Xu F, Jiang M, Li D, Yu P, Ma H, Lu H. Protective effects of antibiotic resistant bacteria on susceptibles in biofilm: Influential factors, mechanism, and modeling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172668. [PMID: 38663625 DOI: 10.1016/j.scitotenv.2024.172668] [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: 01/26/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 05/05/2024]
Abstract
In environmental biofilms, antibiotic-resistant bacteria facilitate the persistence of susceptible counterparts under antibiotic stresses, contributing to increased community-level resistance. However, there is a lack of quantitative understanding of this protective effect and its influential factors, hindering accurate risk assessment of biofilm resistance in diverse environment. This study isolated an opportunistic Escherichia coli pathogen from soil, and engineered it with plasmids conferring antibiotic resistance. Protective effects of the ampicillin resistant strain (AmpR) on their susceptible counterparts (AmpS) were observed in ampicillin-stress colony biofilms. The concentration of ampicillin delineated protective effects into 3 zones: continuous protection (<1 MIC of AmpS), initial AmpS/R dependent (1-8 MIC of AmpS), and ineffective (>8 MIC of AmpS). Intriguingly, Zone 2 exhibited a surprising "less is more" phenomenon tuned by the initial AmpS/R ratio, where biofilm with an initially lower AmpR (1:50 vs 50:1) harbored 30-90 % more AmpR after 24 h growth under antibiotic stress. Compared to AmpS, AmpR displayed superiority in adhesion, antibiotic degradation, motility, and quorum sensing, allowing them to preferentially colonize biofilm edge and areas with higher ampicillin. An agent-based model incorporating protective effects successfully simulated tempo-spatial dynamics of AmpR and AmpS influenced by antibiotic stress and initial AmpS/R. This study provides a holistic view on the pervasive but poorly understood protective effects in biofilm, enabling development of better risk assessment and precisely targeted control strategies of biofilm resistance in diverse environment.
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Affiliation(s)
- Fengqian Xu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Minxi Jiang
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - Dan Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Pingfeng Yu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - He Ma
- Institute of Process Equipment, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Huijie Lu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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2
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Liu X, Lertsethtakarn P, Mariscal VT, Yildiz F, Ottemann KM. Counterclockwise rotation of the flagellum promotes biofilm initiation in Helicobacter pylori. mBio 2024; 15:e0044024. [PMID: 38700325 DOI: 10.1128/mbio.00440-24] [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: 02/14/2024] [Accepted: 03/26/2024] [Indexed: 05/05/2024] Open
Abstract
Motility promotes biofilm initiation during the early steps of this process: microbial surface association and attachment. Motility is controlled in part by chemotaxis signaling, so it seems reasonable that chemotaxis may also affect biofilm formation. There is a gap, however, in our understanding of the interactions between chemotaxis and biofilm formation, partly because most studies analyzed the phenotype of only a single chemotaxis signaling mutant, e.g., cheA. Here, we addressed the role of chemotaxis in biofilm formation using a full set of chemotaxis signaling mutants in Helicobacter pylori, a class I carcinogen that infects more than half the world's population and forms biofilms. Using mutants that lack each chemotaxis signaling protein, we found that chemotaxis signaling affected the biofilm initiation stage, but not mature biofilm formation. Surprisingly, some chemotaxis mutants elevated biofilm initiation, while others inhibited it in a manner that was not tied to chemotaxis ability or ligand input. Instead, the biofilm phenotype correlated with flagellar rotational bias. Specifically, mutants with a counterclockwise bias promoted biofilm initiation, e.g., ∆cheA, ∆cheW, or ∆cheV1; in contrast, those with a clockwise bias inhibited it, e.g., ∆cheZ, ∆chePep, or ∆cheV3. We tested this correlation using a counterclockwise bias-locked flagellum, which induced biofilm formation independent of the chemotaxis system. These CCW flagella, however, were not sufficient to induce biofilm formation, suggesting there are downstream players. Overall, our work highlights the new finding that flagellar rotational direction promotes biofilm initiation, with the chemotaxis signaling system operating as one mechanism to control flagellar rotation. IMPORTANCE Chemotaxis signaling systems have been reported to contribute to biofilm formation in many bacteria; however, how they regulate biofilm formation remains largely unknown. Chemotaxis systems are composed of many distinct kinds of proteins, but most previous work analyzed the biofilm effect of loss of only a few. Here, we explored chemotaxis' role during biofilm formation in the human-associated pathogenic bacterium Helicobacter pylori. We found that chemotaxis proteins are involved in biofilm initiation in a manner that correlated with how they affected flagellar rotation. Biofilm initiation was high in mutants with counterclockwise (CCW) flagellar bias and low in those with clockwise bias. We supported the idea that a major driver of biofilm formation is flagellar rotational direction using a CCW-locked flagellar mutant, which stays CCW independent of chemotaxis input and showed elevated biofilm initiation. Our data suggest that CCW-rotating flagella, independent of chemotaxis inputs, are a biofilm-promoting signal.
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Affiliation(s)
- Xiaolin Liu
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Paphavee Lertsethtakarn
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Vanessa T Mariscal
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Fitnat Yildiz
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
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3
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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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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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5
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Suzuki S, Yokota K, Igimi S, Kajikawa A. Negative chemotaxis of Ligilactobacillus agilis BKN88 against gut-derived substances. Sci Rep 2023; 13:15632. [PMID: 37730901 PMCID: PMC10511705 DOI: 10.1038/s41598-023-42840-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023] Open
Abstract
Ligilactobacillus agilis is a motile lactic acid bacterium found in the gastrointestinal tracts of animals. The findings of our previous study suggest that the motility of L. agilis BKN88 enables gut colonization in murine models. However, the chemotactic abilities of motile lactobacilli remain unknown. This study aimed to identify the gut-derived chemoeffectors and their corresponding chemoreceptors in L. agilis BKN88. Chemotaxis assays with chemotactic and non-chemotactic (ΔcheA) L. agilis strains revealed that low pH, organic acids, and bile salts served as repellents. L. agilis BKN88 was more sensitive to bile and acid than the gut-derived non-motile lactobacilli, implying that L. agilis might utilize motility and chemotaxis instead of exhibiting stress tolerance/resistance. L. agilis BKN88 contains five putative chemoreceptor genes (mcp1-mcp5). Chemotaxis assays using a series of chemoreceptor mutants revealed that each of the five chemoreceptors could sense multiple chemoeffectors and that these chemoreceptors were functionally redundant. Mcp2 and Mcp3 sensed all tested chemoeffectors. This study provides further insights into the interactions between chemoreceptors and ligands of motile lactobacilli and the unique ecological and evolutionary features of motile lactobacilli, which may be distinct from those of non-motile lactobacilli.
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Affiliation(s)
- Shunya Suzuki
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo, 156-8502, Japan
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Kenji Yokota
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo, 156-8502, Japan
| | - Shizunobu Igimi
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo, 156-8502, Japan
| | - Akinobu Kajikawa
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo, 156-8502, Japan.
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Elshenawi Y, Hu S, Hathroubi S. Biofilm of Helicobacter pylori: Life Cycle, Features, and Treatment Options. Antibiotics (Basel) 2023; 12:1260. [PMID: 37627679 PMCID: PMC10451559 DOI: 10.3390/antibiotics12081260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori's chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, shifted morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori-targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm-targeted treatment strategies.
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Affiliation(s)
- Yasmine Elshenawi
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Shuai Hu
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Skander Hathroubi
- Spartha Medical, CRBS 1 Rue Eugène Boeckel, 67000 Strasbourg, France
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7
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Gupta N, Kumar A, Verma VK. Strategies adopted by gastric pathogen Helicobacter pylori for a mature biofilm formation: Antimicrobial peptides as a visionary treatment. Microbiol Res 2023; 273:127417. [PMID: 37267815 DOI: 10.1016/j.micres.2023.127417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/15/2023] [Accepted: 05/21/2023] [Indexed: 06/04/2023]
Abstract
Enormous efforts in recent past two decades to eradicate the pathogen that has been prevalent in half of the world's population have been problematic. The biofilm formed by Helicobacter pylori provides resistance towards innate immune cells, various combinatorial antibiotics, and human antimicrobial peptides, despite the fact that these all are potent enough to eradicate it in vitro. Biofilm provides the opportunity to secrete various virulence factors that strengthen the interaction between host and pathogen helping in evading the innate immune system and ultimately leading to persistence. To our knowledge, this review is the first of its kind to explain briefly the journey of H. pylori starting with the chemotaxis, the mechanism for selecting the site for colonization, the stress faced by the pathogen, and various adaptations to evade these stress conditions by forming biofilm and the morphological changes acquired by the pathogen in mature biofilm. Furthermore, we have explained the human GI tract antimicrobial peptides and the reason behind the failure of these AMPs, and how encapsulation of Pexiganan-A(MSI-78A) in a chitosan microsphere increases the efficiency of eradication.
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Affiliation(s)
- Nidhi Gupta
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Marg, New Delhi 110021, India.
| | - Atul Kumar
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Marg, New Delhi 110021, India
| | - Vijay Kumar Verma
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Marg, New Delhi 110021, India.
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8
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Yang H, Wang L, Zhang M, Hu B. The Role of Adhesion in Helicobacter pylori Persistent Colonization. Curr Microbiol 2023; 80:185. [PMID: 37071212 DOI: 10.1007/s00284-023-03264-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 03/10/2023] [Indexed: 04/19/2023]
Abstract
Helicobacter pylori (H. pylori) has coevolved with its human host for more than 100 000 years. It can safely colonize around the epithelium of gastric glands via their specific microstructures and proteins. Unless patients receive eradication treatment, H. pylori infection is always lifelong. However, few studies have discussed the reasons. This review will focus on the adhesion of H. pylori from the oral cavity to gastric mucosa and summarize the possible binding and translocation characteristics. Adhesion is the first step for persistent colonization after the directional motility, and factors related to adhesion are necessary. Outer membrane proteins, such as the blood group antigen binding adhesin (BabA) and the sialic acid binding adhesin (SabA), play pivotal roles in binding to human mucins and cellular surfaces. And this may offer different perspectives on eradication.
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Affiliation(s)
- Hang Yang
- Department of Gastroenterology, West China Hospital, Sichuan University, No.37, Guo Xue Alley, Wu Hou District, Chengdu City, 610041, Sichuan Province, China
| | - Lixia Wang
- The Second Department of Gastroenterology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Miao Zhang
- Department of Gastroenterology, West China Hospital, Sichuan University, No.37, Guo Xue Alley, Wu Hou District, Chengdu City, 610041, Sichuan Province, China
| | - Bing Hu
- Department of Gastroenterology, West China Hospital, Sichuan University, No.37, Guo Xue Alley, Wu Hou District, Chengdu City, 610041, Sichuan Province, China.
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9
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Helicobacter pylori Chronic-Stage Inflammation Undergoes Fluctuations That Are Altered in tlpA Mutants. Infect Immun 2023; 91:e0032222. [PMID: 36533917 PMCID: PMC9872690 DOI: 10.1128/iai.00322-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Helicobacter pylori colonizes half of the world's population and is responsible for a significant disease burden by causing gastritis, peptic ulcers, and gastric cancer. The development of host inflammation drives these diseases, but there are still open questions in the field about how H. pylori controls this process. We characterized H. pylori inflammation using an 8-month mouse infection time course and comparison of the wild type (WT) and a previously identified mutant lacking the TlpA chemoreceptor that causes elevated inflammation. Our work shows that H. pylori chronic-stage corpus inflammation undergoes surprising fluctuations, with changes in Th17 and eosinophil numbers. The H. pylori tlpA mutant changed the inflammation temporal characteristics, resulting in different inflammation from the wild type at some time points. tlpA mutants have equivalent total and gland colonization in late-stage infections. During early infection, in contrast, they show elevated gland and total colonization compared to those by WT. Our results suggest the chronic inflammation setting is dynamic and may be influenced by colonization properties of early infection.
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10
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Laganenka L, Sourjik V. Bacterial Quorum Sensing Signals at the Interdomain Interface. Isr J Chem 2022. [DOI: 10.1002/ijch.202200080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO) Marburg Germany
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11
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Moadelighomi SZJ, Mirpour M, Ghasemi MF. Eugenol contributes to decreased expression of rpoD and genes in clinically isolated Helicobacter pylori: An in vitro study using real-time-PCR technique. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Schwarz J, Schumacher K, Brameyer S, Jung K. Bacterial battle against acidity. FEMS Microbiol Rev 2022; 46:6652135. [PMID: 35906711 DOI: 10.1093/femsre/fuac037] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Accepted: 07/27/2022] [Indexed: 01/09/2023] Open
Abstract
The Earth is home to environments characterized by low pH, including the gastrointestinal tract of vertebrates and large areas of acidic soil. Most bacteria are neutralophiles, but can survive fluctuations in pH. Herein, we review how Escherichia, Salmonella, Helicobacter, Brucella, and other acid-resistant Gram-negative bacteria adapt to acidic environments. We discuss the constitutive and inducible defense mechanisms that promote survival, including proton-consuming or ammonia-producing processes, cellular remodeling affecting membranes and chaperones, and chemotaxis. We provide insights into how Gram-negative bacteria sense environmental acidity using membrane-integrated and cytosolic pH sensors. Finally, we address in more detail the powerful proton-consuming decarboxylase systems by examining the phylogeny of their regulatory components and their collective functionality in a population.
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Affiliation(s)
- Julia Schwarz
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kilian Schumacher
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Sophie Brameyer
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kirsten Jung
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
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13
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Lin Q, Li M, Wang Y, Xu Z, Li L. Root exudates and chemotactic strains mediate bacterial community assembly in the rhizosphere soil of Casuarina equisetifolia L. FRONTIERS IN PLANT SCIENCE 2022; 13:988442. [PMID: 36212345 PMCID: PMC9534574 DOI: 10.3389/fpls.2022.988442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/02/2022] [Indexed: 05/31/2023]
Abstract
Rhizosphere bacterial diversity and community structure are important factors involving in plant growth. However, the exact process of how plant rhizosphere bacterial community structures is assembled remains unclear. To investigate the role of bacterial chemotaxis to rhizosphere secretions in the establishment of rhizosphere microbial community in Casuarina equisetifolia, we screened bacteria strains derived from the rhizosphere of Casuarina equisetifolia L. using top three chemicals of the plant root exudates (2,4-di-tert-butylphenol, methyl stearate, and arginine) as chemoattractant. Among 72 bacterial strains, five showed strong chemotaxis to 2,4-di-tert-butylphenol, six to methyl stearate, and eleven to arginine, with the highest bacterial chemotaxis occurring at a concentration of 60 μM. This indicates that arginine is a more important chemoattractant than 2,4-di-tert-butylphenol, methyl stearate in the establishment of rhizosphere microbial community in Casuarina equisetifolia. Bacterial community assembly analysis using different chemoattractants and chemoattractants-plus-bacteria combinations were then performed by burying laboratory prepared bags of sterlized soil into C. equisetifolia forest. Bacteria diversity and enrichment analyses using 16S rDNA sequencing at 7 and 14 days after burying showed that arginine-plus-Ochrobactrum sp. and Pantoea sp. treatment exhibited the greatest similarity to the natural forest bacterial community. Our date provides new insights into how chemoattractants and chemotactic bacteria strains shape the rhizosphere microbial community of C. equisetifolia, which constitutes foundational information for future management of these communities.
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14
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Yang H, Huang X, Zhang X, Zhang X, Xu X, She F, Wen Y. AI-2 Induces Urease Expression Through Downregulation of Orphan Response Regulator HP1021 in Helicobacter pylori. Front Med (Lausanne) 2022; 9:790994. [PMID: 35433748 PMCID: PMC9010608 DOI: 10.3389/fmed.2022.790994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Helicobacter pylori causes gastric infections in more than half of the world's population. The bacterium's survival in the stomach is mediated by the abundant production of urease to enable acid acclimation. In this study, our transcriptomic analysis demonstrated that the expression of urease structural proteins, UreA and UreB, is induced by the autoinducer AI-2 in H. pylori. We also found that the orphan response regulator HP1021 is downregulated by AI-2, resulting in the induction of urease expression. HP1021 represses the expression of urease by directly binding to the promoter region of ureAB, ranging from −47 to +3 with respect to the transcriptional start site. The study findings suggest that quorum sensing via AI-2 enhances acid acclimation when bacterial density increases, and might enable bacterial dispersal to other sites when entering gastric acid.
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Affiliation(s)
- Huang Yang
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xiaoxing Huang
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xiaochuan Zhang
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xiaoyan Zhang
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Xiaohong Xu
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
- Fujian Medical University Union Hospital, Fuzhou, China
| | - Feifei She
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
- *Correspondence: Feifei She
| | - Yancheng Wen
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
- Yancheng Wen
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15
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Insall RH, Paschke P, Tweedy L. Steering yourself by the bootstraps: how cells create their own gradients for chemotaxis. Trends Cell Biol 2022; 32:585-596. [DOI: 10.1016/j.tcb.2022.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 10/18/2022]
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16
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Transcriptome Analysis of the Response of Mature Helicobacter pylori Biofilm to Different Doses of Lactobacillus salivarius LN12 with Amoxicillin and Clarithromycin. Antibiotics (Basel) 2022; 11:antibiotics11020262. [PMID: 35203863 PMCID: PMC8868532 DOI: 10.3390/antibiotics11020262] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/13/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
Helicobacter pylori is a gastrointestinal pathogen with a high infection rate. Probiotics are clinically used as an adjuvant to improve the cure rate and reduce the side effects of antibiotic treatment for H. pylori. This study is the first to explore the effects of a cell-free supernatant of high- or low-dose Lactobacillus salivarius LN12 combined with amoxicillin (AMX) and clarithromycin (CLR) on H. pylori 3192 biofilms in terms of the biofilm biomass, survival rates, biofilm structure, and transcriptome. The results showed that the combination of the CFS of high-dose LN12 with AMX and CLR had stronger effects on the biofilm biomass, survival rate, and structure of H. pylori 3192 biofilms. H. pylori 3192 biofilms may increase the expression of NADH-related genes and downregulate flagellar assembly and quorum sensing-related receptor genes to deal with the stronger stress effects of high-dose LN12 with AMX and CLR. In conclusion, the biofilm biomass, survival rate, structure, and transcriptome results showed that the combination of LN12 CFS with AMX and CLR had dose effects. We recommend that compared with low doses, high doses of L. salivarus LN12 combined with AMX and CLR may be more effective for H. pylori biofilm than low doses.
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17
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Fan Q, Wang H, Mao C, Li J, Zhang X, Grenier D, Yi L, Wang Y. Structure and Signal Regulation Mechanism of Interspecies and Interkingdom Quorum Sensing System Receptors. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:429-445. [PMID: 34989570 DOI: 10.1021/acs.jafc.1c04751] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Quorum sensing (QS) is a signaling mechanism for cell-to-cell communication between bacteria, fungi, and even eukaryotic hosts such as plant and animal cells. Bacteria in real life do not exist as isolated organisms but are found in complex, dynamic, and microecological environments. The study of interspecies QS and interkingdom QS is a valuable approach for exploring bacteria-bacteria interactions and bacteria-host interaction mechanisms and has received considerable attention from researchers. The correct combination of QS signals and receptors is key to initiating the QS process. Compared with intraspecies QS, the signal regulation mechanism of interspecies QS and interkingdom QS is often more complicated, and the distribution of receptors is relatively wide. The present review focuses on the latest progress with respect to the distribution, structure, and signal transduction of interspecies and interkingdom QS receptors and provides a guide for the investigation of new QS receptors in the future.
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Affiliation(s)
- Qingying Fan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Haikun Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Chenlong Mao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Jinpeng Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Xiaoling Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
| | - Daniel Grenier
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec G1 V 0A6, Canada
| | - Li Yi
- College of Life Science, Luoyang Normal University, Luoyang 471023, China
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471000, China
- Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang 471000, China
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18
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Colin R, Ni B, Laganenka L, Sourjik V. Multiple functions of flagellar motility and chemotaxis in bacterial physiology. FEMS Microbiol Rev 2021; 45:fuab038. [PMID: 34227665 PMCID: PMC8632791 DOI: 10.1093/femsre/fuab038] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022] Open
Abstract
Most swimming bacteria are capable of following gradients of nutrients, signaling molecules and other environmental factors that affect bacterial physiology. This tactic behavior became one of the most-studied model systems for signal transduction and quantitative biology, and underlying molecular mechanisms are well characterized in Escherichia coli and several other model bacteria. In this review, we focus primarily on less understood aspect of bacterial chemotaxis, namely its physiological relevance for individual bacterial cells and for bacterial populations. As evident from multiple recent studies, even for the same bacterial species flagellar motility and chemotaxis might serve multiple roles, depending on the physiological and environmental conditions. Among these, finding sources of nutrients and more generally locating niches that are optimal for growth appear to be one of the major functions of bacterial chemotaxis, which could explain many chemoeffector preferences as well as flagellar gene regulation. Chemotaxis might also generally enhance efficiency of environmental colonization by motile bacteria, which involves intricate interplay between individual and collective behaviors and trade-offs between growth and motility. Finally, motility and chemotaxis play multiple roles in collective behaviors of bacteria including swarming, biofilm formation and autoaggregation, as well as in their interactions with animal and plant hosts.
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Affiliation(s)
- Remy Colin
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
| | - Bin Ni
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
- College of Resources and Environmental Science, National Academy of Agriculture Green Development, China Agricultural University, Yuanmingyuan Xilu No. 2, Beijing 100193, China
| | - Leanid Laganenka
- Institute of Microbiology, D-BIOL, ETH Zürich, Vladimir-Prelog-Weg 4, Zürich 8093, Switzerland
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
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The dCache Chemoreceptor TlpA of Helicobacter pylori Binds Multiple Attractant and Antagonistic Ligands via Distinct Sites. mBio 2021; 12:e0181921. [PMID: 34340539 PMCID: PMC8406319 DOI: 10.1128/mbio.01819-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The Helicobacter pylori chemoreceptor TlpA plays a role in dampening host inflammation during chronic stomach colonization. TlpA has a periplasmic dCache_1 domain, a structure that is capable of sensing many ligands; however, the only characterized TlpA signals are arginine, bicarbonate, and acid. To increase our understanding of TlpA’s sensing profile, we screened for diverse TlpA ligands using ligand binding arrays. TlpA bound seven ligands with affinities in the low- to middle-micromolar ranges. Three of these ligands, arginine, fumarate, and cysteine, were TlpA-dependent chemoattractants, while the others elicited no response. Molecular docking experiments, site-directed point mutants, and competition surface plasmon resonance binding assays suggested that TlpA binds ligands via both the membrane-distal and -proximal dCache_1 binding pockets. Surprisingly, one of the nonactive ligands, glucosamine, acted as a chemotaxis antagonist, preventing the chemotaxis response to chemoattractant ligands, and acted to block the binding of ligands irrespective of whether they bound the membrane-distal or -proximal dCache_1 subdomains. In total, these results suggest that TlpA senses multiple attractant ligands as well as antagonist ones, an emerging theme in chemotaxis systems.
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20
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Small RNA mediated gradual control of lipopolysaccharide biosynthesis affects antibiotic resistance in Helicobacter pylori. Nat Commun 2021; 12:4433. [PMID: 34290242 PMCID: PMC8295292 DOI: 10.1038/s41467-021-24689-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
The small, regulatory RNA RepG (Regulator of polymeric G-repeats) regulates the expression of the chemotaxis receptor TlpB in Helicobacter pylori by targeting a variable G-repeat in the tlpB mRNA leader. Here, we show that RepG additionally controls lipopolysaccharide (LPS) phase variation by also modulating the expression of a gene (hp0102) that is co-transcribed with tlpB. The hp0102 gene encodes a glycosyltransferase required for LPS O-chain biosynthesis and in vivo colonization of the mouse stomach. The G-repeat length defines a gradual (rather than ON/OFF) control of LPS biosynthesis by RepG, and leads to gradual resistance to a membrane-targeting antibiotic. Thus, RepG-mediated modulation of LPS structure might impact host immune recognition and antibiotic sensitivity, thereby helping H. pylori to adapt and persist in the host. The small RNA RepG modulates expression of chemotaxis receptor TlpB in Helicobacter pylori by targeting a length-variable G-repeat in the tlpB mRNA. Here, Pernitzsch et al. show that RepG also gradually controls lipopolysaccharide biosynthesis, antibiotic susceptibility, and in-vivo colonization of the stomach, by regulating a gene that is co-transcribed with tlpB.
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21
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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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22
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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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23
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Matilla MA, Ortega Á, Krell T. The role of solute binding proteins in signal transduction. Comput Struct Biotechnol J 2021; 19:1786-1805. [PMID: 33897981 PMCID: PMC8050422 DOI: 10.1016/j.csbj.2021.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
The solute binding proteins (SBPs) of prokaryotes are present in the extracytosolic space. Although their primary function is providing substrates to transporters, SBPs also stimulate different signaling proteins, including chemoreceptors, sensor kinases, diguanylate cyclases/phosphodiesterases and Ser/Thr kinases, thereby causing a wide range of responses. While relatively few such systems have been identified, several pieces of evidence suggest that SBP-mediated receptor activation is a widespread mechanism. (1) These systems have been identified in Gram-positive and Gram-negative bacteria and archaea. (2) There is a structural diversity in the receptor domains that bind SBPs. (3) SBPs belonging to thirteen different families interact with receptor ligand binding domains (LBDs). (4) For the two most abundant receptor LBD families, dCache and four-helix-bundle, there are different modes of interaction with SBPs. (5) SBP-stimulated receptors carry out many different functions. The advantage of SBP-mediated receptor stimulation is attributed to a strict control of SBP levels, which allows a precise adjustment of the systeḿs sensitivity. We have compiled information on the effect of ligands on the transcript/protein levels of their cognate SBPs. In 87 % of the cases analysed, ligands altered SBP expression levels. The nature of the regulatory effect depended on the ligand family. Whereas inorganic ligands typically downregulate SBP expression, an upregulation was observed in response to most sugars and organic acids. A major unknown is the role that SBPs play in signaling and in receptor stimulation. This review attempts to summarize what is known and to present new information to narrow this gap in knowledge.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada 18008, Spain
| | - Álvaro Ortega
- Department of Biochemistry and Molecular Biology 'B' and Immunology, Faculty of Chemistry, University of Murcia, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada 18008, Spain
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24
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Molecular Mechanisms of Campylobacter Biofilm Formation and Quorum Sensing. Curr Top Microbiol Immunol 2021. [PMID: 33620656 DOI: 10.1007/978-3-030-65481-8_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Even though Campylobacter spp. are known to be fastidious organisms, they can survive within the natural environment. One mechanism to withstand unfavourable conditions is the formation of biofilms, a multicellular structure composed of different bacterial and other microbial species which are embedded in an extracellular matrix. High oxygen levels, low substrate concentrations and the presence of external DNA stimulate the biofilm formation by C. jejuni. These external factors trigger internal adaptation processes, e.g. via regulating the expression of genes encoding proteins required for surface structure formation, as well as motility, stress response and antimicrobial resistance. Known genes impacting biofilm formation will be summarized in this review. The formation of biofilms as well as the expression of virulence genes is often regulated in a cell density depending manner by quorum sensing, which is mediated via small signalling molecules termed autoinducers. Even though quorum sensing mechanisms of other bacteria are well understood, knowledge on the role of these mechanisms in C. jejuni biofilm formation is still scarce. The LuxS enzyme involved in generation of autoinducer-2 is present in C. jejuni, but autoinducer receptors have not been identified so far. Phenotypes of C. jejuni strains lacking a functional luxS like reduced growth, motility, oxygen stress tolerance, biofilm formation, adhesion, invasion and colonization are also summarized within this chapter. However, these phenotypes are highly variable in distinct C. jejuni strains and depend on the culture conditions applied.
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25
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Koshy-Chenthittayil S, Archambault L, Senthilkumar D, Laubenbacher R, Mendes P, Dongari-Bagtzoglou A. Agent Based Models of Polymicrobial Biofilms and the Microbiome-A Review. Microorganisms 2021; 9:417. [PMID: 33671308 PMCID: PMC7922883 DOI: 10.3390/microorganisms9020417] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/05/2021] [Accepted: 02/16/2021] [Indexed: 02/06/2023] Open
Abstract
The human microbiome has been a focus of intense study in recent years. Most of the living organisms comprising the microbiome exist in the form of biofilms on mucosal surfaces lining our digestive, respiratory, and genito-urinary tracts. While health-associated microbiota contribute to digestion, provide essential nutrients, and protect us from pathogens, disturbances due to illness or medical interventions contribute to infections, some that can be fatal. Myriad biological processes influence the make-up of the microbiota, for example: growth, division, death, and production of extracellular polymers (EPS), and metabolites. Inter-species interactions include competition, inhibition, and symbiosis. Computational models are becoming widely used to better understand these interactions. Agent-based modeling is a particularly useful computational approach to implement the various complex interactions in microbial communities when appropriately combined with an experimental approach. In these models, each cell is represented as an autonomous agent with its own set of rules, with different rules for each species. In this review, we will discuss innovations in agent-based modeling of biofilms and the microbiota in the past five years from the biological and mathematical perspectives and discuss how agent-based models can be further utilized to enhance our comprehension of the complex world of polymicrobial biofilms and the microbiome.
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Affiliation(s)
- Sherli Koshy-Chenthittayil
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA; (S.K.-C.); (L.A.); (P.M.)
| | - Linda Archambault
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA; (S.K.-C.); (L.A.); (P.M.)
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | | | | - Pedro Mendes
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA; (S.K.-C.); (L.A.); (P.M.)
- Center for Cell Analysis and Modeling, Department of Cell Biology, University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | - Anna Dongari-Bagtzoglou
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
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Qiu X, Zhang Y, Hong H. Classification of acetic acid bacteria and their acid resistant mechanism. AMB Express 2021; 11:29. [PMID: 33595734 PMCID: PMC7889782 DOI: 10.1186/s13568-021-01189-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 02/04/2021] [Indexed: 12/14/2022] Open
Abstract
Acetic acid bacteria (AAB) are obligate aerobic Gram-negative bacteria that are commonly used in vinegar fermentation because of their strong capacity for ethanol oxidation and acetic acid synthesis as well as their acid resistance. However, low biomass and low production rate due to acid stress are still major challenges that must be overcome in industrial processes. Although acid resistance in AAB is important to the production of high acidity vinegar, the acid resistance mechanisms of AAB have yet to be fully elucidated. In this study, we discuss the classification of AAB species and their metabolic processes and review potential acid resistance factors and acid resistance mechanisms in various strains. In addition, we analyze the quorum sensing systems of Komagataeibacter and Gluconacetobacter to provide new ideas for investigation of acid resistance mechanisms in AAB in the form of signaling pathways. The results presented herein will serve as an important reference for selective breeding of high acid resistance AAB and optimization of acetic acid fermentation processes.
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Affiliation(s)
- Xiaoman Qiu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
- National Engineering Technique Research Center for Biotechnology, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Yao Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
- National Engineering Technique Research Center for Biotechnology, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China
| | - Housheng Hong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China.
- National Engineering Technique Research Center for Biotechnology, Nanjing Tech University, No. 30, Puzhu Road, Nanjing, 211800, China.
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27
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Antani JD, Sumali AX, Lele TP, Lele PP. Asymmetric random walks reveal that the chemotaxis network modulates flagellar rotational bias in Helicobacter pylori. eLife 2021; 10:63936. [PMID: 33493107 PMCID: PMC7834020 DOI: 10.7554/elife.63936] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
The canonical chemotaxis network modulates the bias for a particular direction of rotation in the bacterial flagellar motor to help the cell migrate toward favorable chemical environments. How the chemotaxis network in Helicobacter pylori modulates flagellar functions is unknown, which limits our understanding of chemotaxis in this species. Here, we determined that H. pylori swim faster (slower) whenever their flagella rotate counterclockwise (clockwise) by analyzing their hydrodynamic interactions with bounding surfaces. This asymmetry in swimming helped quantify the rotational bias. Upon exposure to a chemo-attractant, the bias decreased and the cells tended to swim exclusively in the faster mode. In the absence of a key chemotaxis protein, CheY, the bias was zero. The relationship between the reversal frequency and the rotational bias was unimodal. Thus, H. pylori’s chemotaxis network appears to modulate the probability of clockwise rotation in otherwise counterclockwise-rotating flagella, similar to the canonical network.
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Affiliation(s)
- Jyot D Antani
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, United States
| | - Anita X Sumali
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, United States
| | - Tanmay P Lele
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77840, College Station, TX 77840, United States.,Department of Translational Medical Sciences, Texas A&M University, Houston, TX 77030, United States
| | - Pushkar P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, United States
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Genetic requirements and transcriptomics of Helicobacter pylori biofilm formation on abiotic and biotic surfaces. NPJ Biofilms Microbiomes 2020; 6:56. [PMID: 33247117 PMCID: PMC7695850 DOI: 10.1038/s41522-020-00167-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/30/2020] [Indexed: 12/16/2022] Open
Abstract
Biofilm growth is a widespread mechanism that protects bacteria against harsh environments, antimicrobials, and immune responses. These types of conditions challenge chronic colonizers such as Helicobacter pylori but it is not fully understood how H. pylori biofilm growth is defined and its impact on H. pylori survival. To provide insights into H. pylori biofilm growth properties, we characterized biofilm formation on abiotic and biotic surfaces, identified genes required for biofilm formation, and defined the biofilm-associated gene expression of the laboratory model H. pylori strain G27. We report that H. pylori G27 forms biofilms with a high biomass and complex flagella-filled 3D structures on both plastic and gastric epithelial cells. Using a screen for biofilm-defective mutants and transcriptomics, we discovered that biofilm cells demonstrated lower transcripts for TCA cycle enzymes but higher ones for flagellar formation, two type four secretion systems, hydrogenase, and acetone metabolism. We confirmed that biofilm formation requires flagella, hydrogenase, and acetone metabolism on both abiotic and biotic surfaces. Altogether, these data suggest that H. pylori is capable of adjusting its phenotype when grown as biofilm, changing its metabolism, and re-shaping flagella, typically locomotion organelles, into adhesive structures.
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29
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Khan F, Javaid A, Kim YM. Functional Diversity of Quorum Sensing Receptors in Pathogenic Bacteria: Interspecies, Intraspecies and Interkingdom Level. Curr Drug Targets 2020; 20:655-667. [PMID: 30468123 DOI: 10.2174/1389450120666181123123333] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/16/2018] [Accepted: 11/16/2018] [Indexed: 01/17/2023]
Abstract
The formation of biofilm by pathogenic bacteria is considered as one of the most powerful mechanisms/modes of resistance against the action of several antibiotics. Biofilm is formed as a structural adherent over the surfaces of host, food and equipments etc. and is further functionally coordinated by certain chemicals produced itself. These chemicals are known as quorum sensing (QS) signaling molecules and are involved in the cross talk at interspecies, intraspecies and interkingdom levels thus resulting in the production of virulence factors leading to pathogenesis. Bacteria possess receptors to sense these chemicals, which interact with the incoming QS molecules. It is followed by the secretion of virulence molecules, regulation of bioluminescence, biofilm formation, antibiotic resistance development and motility behavioral responses. In the natural environment, different bacterial species (Gram-positive and Gram-negative) produce QS signaling molecules that are structurally and functionally different. Recent and past research shows that various antagonistic molecules (naturally and chemically synthesized) are characterized to inhibit the formation of biofilm and attenuation of bacterial virulence by blocking the QS receptors. This review article describes about the diverse QS receptors at their structural, functional and production levels. Thus, by blocking these receptors with inhibitory molecules can be a potential therapeutic approach to control pathogenesis. Furthermore, these receptors can also be used as a structural platform to screen the most potent inhibitors with the help of bioinformatics approaches.
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Affiliation(s)
- Fazlurrahman Khan
- Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, South Korea.,Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida 201306, U.P, India
| | - Aqib Javaid
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida 201306, U.P, India
| | - Young-Mog Kim
- Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, South Korea.,Department of Food Science and Technology, Pukyong National University, Busan 48513, South Korea
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30
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Tan PY, Marcos, Liu Y. Modelling bacterial chemotaxis for indirectly binding attractants. J Theor Biol 2020; 487:110120. [PMID: 31857084 DOI: 10.1016/j.jtbi.2019.110120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/09/2019] [Accepted: 12/16/2019] [Indexed: 11/26/2022]
Abstract
In bacterial chemotaxis, chemoattractant molecules may bind either directly or indirectly with receptors within the cell periplasmic space. The indirect binding mechanism, which involves an intermediate periplasmic binding protein, has been reported to increase sensitivity to dilute attractant concentrations as well as range of response. Current mathematical models for bacterial chemotaxis at the population scale do not appear to take the periplasmic binding protein (BP) concentration or the indirect binding mechanics into account. We formulate an indirect binding extension to the existing Rivero equation for chemotactic velocity based on fundamental reversible enzyme kinetics. The formulated indirect binding expression accounts for the periplasmic BP concentration and the dissociation constants for binding between attractant and periplasmic BP, as well as between BP and chemoreceptor. We validate the indirect-binding model using capillary assay simulations of the chemotactic responses of E. coli to the indirectly-binding attractants maltose and AI-2. The predicted response agrees well with experimental data from a number of maltose capillary assay studies conducted in previous literature. The model is also able to achieve good agreement with AI-2 capillary assay data of one study out of two tested. The chemotactic response of E. coli towards AI-2 appears to be of higher complexity due to reports of variable periplasmic BP concentration as well as the low concentration of periplasmic BP relative to the total receptor concentration. Our current model is thus suitable for indirect binding chemotactic response systems with constant periplasmic BP concentration that is significantly larger than the total receptor concentration, such as the response of E. coli towards maltose. Further considerations may be taken into account to model the chemotactic response towards AI-2 with greater accuracy.
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Affiliation(s)
- Pei Yen Tan
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, 637141, Singapore
| | - Marcos
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
| | - Yu Liu
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
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31
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Antimicrobial and Anti-Biofilm Effect of an Electrolyzed Superoxidized Solution at Neutral-pH against Helicobacter pylori. BIOMED RESEARCH INTERNATIONAL 2020; 2019:6154867. [PMID: 31930132 PMCID: PMC6942767 DOI: 10.1155/2019/6154867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/15/2019] [Accepted: 08/02/2019] [Indexed: 01/18/2023]
Abstract
The presence of Helicobacter pylori in the oral cavity has been associated to the failure of antimicrobial therapy in patients with gastrointestinal infection and the development of oral diseases. However, it has been reported that the maintenance of good oral hygiene can improve the therapeutic success rates, where the use of mouthwashes with anti-Helicobacter activity would help to achieve it. The aim was to evaluate the antimicrobial activity of OxOral® mouthwash against H. pylori and its effect on biofilm formation. The minimum inhibitory concentration (MIC) of OxOral® (pH = 6.4–7.5, ORP = 650–900 mV) against H. pylori was calculated testing serial dilutions 0.117–15 ppm against 1 × 108 CFU/mL of H. pylori (ATCC® 700824™) by broth microdilution method using 96‐well plates. The H. pylori biofilm formation was determined by the optical density measurement at 600 nm from coverslips stained with 0.1% crystal violet. The gene expression of ureA, luxS, flaA, omp18, and lpxD were analyzed by RT‐qPCR. OxOral® cytotoxicity was evaluated in a human gingival fibroblast cell line by MTT assay. MIC was of 3.75 ppm, with 99.7 ± 7.7% bacterial growth inhibition. In the negative control, the biofilm formation was observed, whereas when bacteria were treated with OxOral® at 0.234, 0.469, and 0.938 ppm, an inhibition of 35.5 ± 0.9%, 89.1 ± 1.2%, and 99.9 ± 5.5% were obtained, respectively. The gene expression analysis showed that flaA, omp18, and lpxD genes were down‐regulated with OxOral® compared with control (p < 0.05). Low cytotoxicity of 16.5 ± 7.6% was observed at the highest dose (15 ppm); no significant differences were observed from 15 to 0.469 ppm compared to the control of untreated cells (p > 0.05). Our results reveal an important anti-Helicobacter activity of OxOral® and open the possibility of its therapeutic use new studies, which would increase the success rate of conventional therapies against H. pylori.
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Helicobacter pylori Uses the TlpB Receptor To Sense Sites of Gastric Injury. Infect Immun 2019; 87:IAI.00202-19. [PMID: 31262979 DOI: 10.1128/iai.00202-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/18/2019] [Indexed: 01/24/2023] Open
Abstract
Helicobacter pylori is a pathogen that chronically colonizes the stomachs of approximately half of the world's population and contributes to the development of gastric inflammation. We demonstrated previously in vivo that H. pylori uses motility to preferentially colonize injury sites in the mouse stomach. However, the chemoreceptor responsible for sensing gastric injury has not yet been identified. In this study, we utilized murine gastric organoids (gastroids) and mutant H. pylori strains to investigate the components necessary for H. pylori chemotaxis. High-intensity 730-nm light (two-photon photodamage) was used to cause single-cell damage in gastroids, and repair of the damage was monitored over time; complete repair occurred within ∼10 min in uninfected gastroids. Wild-type H. pylori accumulated at the damage site after gastric damage induction. In contrast, mutants lacking motility (ΔmotB) or chemotaxis (ΔcheY) did not accumulate at the injury site. Using mutants lacking individual chemoreceptors, we found that only TlpB was required for H. pylori accumulation, while TlpA, TlpC, and TlpD were dispensable. All strains that were able to accumulate at the damage site limited repair. When urea (an identified chemoattractant sensed by TlpB) was microinjected into the gastroid lumen, it prevented the accumulation of H. pylori at damage sites. Overall, our findings demonstrate that H. pylori colonizes and limits repair at damage sites via chemotactic motility that requires the TlpB chemoreceptor to sense signals generated by gastric epithelial cells.
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Abstract
Bacteria are often found living in aggregated multicellular communities known as biofilms. Biofilms are three-dimensional structures that confer distinct physical and biological properties to the collective of cells living within them. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms of Helicobacter pylori, a common bacterial resident of human stomachs. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterized H. pylori strains with various AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis-defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger-scale emergent properties of biofilms.IMPORTANCE Most bacteria exist in aggregated, three-dimensional structures called biofilms. Although biofilms play important ecological roles in natural and engineered settings, they can also pose societal problems, for example, when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown that Helicobacter pylori bacteria are repulsed by high concentrations of a self-produced molecule, AI-2, and that H. pylori mutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here, we used computer simulations of biofilm formation to show that local H. pylori behavior of repulsion from high AI-2 could explain the overall architecture of H. pylori biofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.
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Ailloud F, Didelot X, Woltemate S, Pfaffinger G, Overmann J, Bader RC, Schulz C, Malfertheiner P, Suerbaum S. Within-host evolution of Helicobacter pylori shaped by niche-specific adaptation, intragastric migrations and selective sweeps. Nat Commun 2019; 10:2273. [PMID: 31118420 PMCID: PMC6531487 DOI: 10.1038/s41467-019-10050-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/10/2019] [Indexed: 02/07/2023] Open
Abstract
The human pathogen Helicobacter pylori displays extensive genetic diversity. While H. pylori is known to evolve during infection, population dynamics inside the gastric environment have not been extensively investigated. Here we obtained gastric biopsies from multiple stomach regions of 16 H. pylori-infected adults, and analyze the genomes of 10 H. pylori isolates from each biopsy. Phylogenetic analyses suggest location-specific evolution and bacterial migration between gastric regions. Migration is significantly more frequent between the corpus and the fundus than with the antrum, suggesting that physiological differences between antral and oxyntic mucosa contribute to spatial partitioning of H. pylori populations. Associations between H. pylori gene polymorphisms and stomach niches suggest that chemotaxis, regulatory functions and outer membrane proteins contribute to specific adaptation to the antral and oxyntic mucosa. Moreover, we show that antibiotics can induce severe population bottlenecks and likely play a role in shaping the population structure of H. pylori. Helicobacter pylori, a bacterial pathogen that infects human stomachs, has high genetic diversity across hosts. Here, Ailloud et al. reveal genetic structuring of H. pylori populations among different stomach regions of individual hosts and find signals of genetic associations with stomach region.
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Affiliation(s)
- Florent Ailloud
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany.,Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany.,DZIF German Center for Infection Research, Munich Site, Munich, Germany.,DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany
| | - Xavier Didelot
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.,Department of Statistics, University of Warwick, Coventry, CV4 7AL, UK
| | - Sabrina Woltemate
- Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany
| | - Gudrun Pfaffinger
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
| | - Jörg Overmann
- DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, 38124, Braunschweig, Germany
| | - Ruth Christiane Bader
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany.,National Reference Center for Helicobacter pylori, Max von Pettenkofer Institute, 80336, Munich, Germany
| | - Christian Schulz
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, 39106, Magdeburg, Germany.,Department of Medicine 2, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Peter Malfertheiner
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, 39106, Magdeburg, Germany.,Department of Medicine 2, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Sebastian Suerbaum
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany. .,Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany. .,DZIF German Center for Infection Research, Munich Site, Munich, Germany. .,DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany. .,National Reference Center for Helicobacter pylori, Max von Pettenkofer Institute, 80336, Munich, Germany.
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35
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Fung C, Tan S, Nakajima M, Skoog EC, Camarillo-Guerrero LF, Klein JA, Lawley TD, Solnick JV, Fukami T, Amieva MR. High-resolution mapping reveals that microniches in the gastric glands control Helicobacter pylori colonization of the stomach. PLoS Biol 2019; 17:e3000231. [PMID: 31048876 PMCID: PMC6497225 DOI: 10.1371/journal.pbio.3000231] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/29/2019] [Indexed: 12/22/2022] Open
Abstract
Lifelong infection of the gastric mucosa by Helicobacter pylori can lead to peptic ulcers and gastric cancer. However, how the bacteria maintain chronic colonization in the face of constant mucus and epithelial cell turnover in the stomach is unclear. Here, we present a new model of how H. pylori establish and persist in stomach, which involves the colonization of a specialized microenvironment, or microniche, deep in the gastric glands. Using quantitative three-dimensional (3D) confocal microscopy and passive CLARITY technique (PACT), which renders tissues optically transparent, we analyzed intact stomachs from mice infected with a mixture of isogenic, fluorescent H. pylori strains with unprecedented spatial resolution. We discovered that a small number of bacterial founders initially establish colonies deep in the gastric glands and then expand to colonize adjacent glands, forming clonal population islands that persist over time. Gland-associated populations do not intermix with free-swimming bacteria in the surface mucus, and they compete for space and prevent newcomers from establishing in the stomach. Furthermore, bacterial mutants deficient in gland colonization are outcompeted by wild-type (WT) bacteria. Finally, we found that host factors such as the age at infection and T-cell responses control bacterial density within the glands. Collectively, our results demonstrate that microniches in the gastric glands house a persistent H. pylori reservoir, which we propose replenishes the more transient bacterial populations in the superficial mucosa.
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Affiliation(s)
- Connie Fung
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Mifuyu Nakajima
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Emma C Skoog
- Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, California, United States of America
| | | | - Jessica A Klein
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Trevor D Lawley
- Host-Microbiota Interactions Laboratory, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Jay V Solnick
- Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, California, United States of America
- Department of Medicine, University of California, Davis School of Medicine, Davis, California, United States of America
- Department of Microbiology and Immunology, University of California, Davis School of Medicine, Davis, California, United States of America
| | - Tadashi Fukami
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Manuel R Amieva
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
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36
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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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Haque S, Yadav DK, Bisht SC, Yadav N, Singh V, Dubey KK, Jawed A, Wahid M, Dar SA. Quorum sensing pathways in Gram-positive and -negative bacteria: potential of their interruption in abating drug resistance. J Chemother 2019; 31:161-187. [DOI: 10.1080/1120009x.2019.1599175] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Gene Expression Laboratory, Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India
| | - Dinesh K. Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Shekhar C. Bisht
- Department of Biotechnology, H.N.B Garhwal University, Srinagar, Uttarakhand, India
| | - Neelam Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Vineeta Singh
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Kashyap Kumar Dubey
- Industrial Biotechnology Laboratory, University Institute of Engineering and Technology, M.D. University, Rohtak, Haryana, India
| | - Arshad Jawed
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Sajad Ahmad Dar
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Departments of Microbiology, University College of Medical Sciences (University of Delhi), Delhi, India
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Teren M, Turonova Michova H, Vondrakova L, Demnerova K. Molecules Autoinducer 2 and cjA and Their Impact on Gene Expression in Campylobacter jejuni. J Mol Microbiol Biotechnol 2019; 28:207-215. [DOI: 10.1159/000495411] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 11/14/2018] [Indexed: 11/19/2022] Open
Abstract
Quorum sensing is a widespread form of cell-to-cell communication, which is based on the production of signaling molecules known as autoinducers (AIs). The first group contains highly species-specific N-acyl homoserine lactones (N-AHLs), generally known as AI-1, which are produced by AHL synthase. The second group, possessing the characteristic structure of a furanone ring, are known as AI-2. The enzyme responsible for their production is S-ribosylhomocysteine lyase (LuxS). In <i>Campylobacter jejuni</i>, AI-2 and LuxS play a role in many important processes, including biofilm formation, stress response, motility, expression of virulence factors, and colonization. However, neither the receptor protein nor the exact structure of the AI-2 molecule have been identified to date. Similarly, little is known about the possible existence of AHL-synthase producing AI-1 and its impact on gene expression. Recently, an analogue of homoserine lactone, called cjA, was isolated from a cell-free supernatant of <i>C. jejuni</i> strain<i></i> 81–176 and from the food isolate c11. The molecule cjA particularly impacted the expression of virulence factors and biofilm formation. This review summarizes the role of AI-2 and cjA in the context of biofilm formation, motility, stress responses, and expression of virulence factors.
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Matilla MA, Krell T. The effect of bacterial chemotaxis on host infection and pathogenicity. FEMS Microbiol Rev 2018; 42:4563582. [PMID: 29069367 DOI: 10.1093/femsre/fux052] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022] Open
Abstract
Chemotaxis enables microorganisms to move according to chemical gradients. Although this process requires substantial cellular energy, it also affords key physiological benefits, including enhanced access to growth substrates. Another important implication of chemotaxis is that it also plays an important role in infection and disease, as chemotaxis signalling pathways are broadly distributed across a variety of pathogenic bacteria. Furthermore, current research indicates that chemotaxis is essential for the initial stages of infection in different human, animal and plant pathogens. This review focuses on recent findings that have identified specific bacterial chemoreceptors and corresponding chemoeffectors associated with pathogenicity. Pathogenicity-related chemoeffectors are either host and niche-specific signals or intermediates of the host general metabolism. Plant pathogens were found to contain an elevated number of chemotaxis signalling genes and functional studies demonstrate that these genes are critical for their ability to enter the host. The expanding body of knowledge of the mechanisms underlying chemotaxis in pathogens provides a foundation for the development of new therapeutic strategies capable of blocking infection and preventing disease by interfering with chemotactic signalling pathways.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
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Kaur A, Capalash N, Sharma P. Quorum sensing in thermophiles: prevalence of autoinducer-2 system. BMC Microbiol 2018; 18:62. [PMID: 29954335 PMCID: PMC6022435 DOI: 10.1186/s12866-018-1204-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 06/19/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Quorum sensing is a mechanism of cell to cell communication that requires the production and detection of signaling molecules called autoinducers. Although mesophilic bacteria is known to utilize this for synchronization of physiological processes such as bioluminescence, virulence, biofilm formation, motility and cell competency through signaling molecules (acyl homoserine lactones, AI-1; oligopeptides, peptide based system and furanosyl borate diester, AI-2), the phenomenon of quorum sensing in thermophiles is largely unknown. RESULTS In this study, proteomes of 106 thermophilic eubacteria and 21 thermophilic archaea have been investigated for the above three major quorum sensing systems to find the existence of quorum sensing in these thermophiles as there are evidences for the formation of biofilms in hot environments. Our investigation demonstrated that AI-1 system is absent in thermophiles. Further, complete peptide based two component systems for quorum sensing was also not found in any thermophile however the traces for the presence of response regulators for peptide based system were found in some of them. BLASTp search using LuxS (AI-2 synthase) protein sequence of Escherichia coli str. K-12 substr. MG1655 and autoinducer-2 receptors (LuxP of Vibrio harveyi, LsrB of E. coli str. K-12 substr. MG1655 and RbsB of Aggregatibacter actinomycetemcomitans) as queries revealed that 17 thermophilic bacteria from phyla Deinococcus- Thermus and Firmicutes possess complete AI-2 system (LuxS and LsrB and/or RbsB). Out of 106 thermophilic eubacteria 18 from phyla Deinococcus- Thermus, Proteobacteria and Firmicutes have only LuxS that might function as AI-2 synthesizing protein whereas, 16 are having only LsrB and/or RbsB which may function as AI-2 receptor in biofilms. CONCLUSIONS We anticipate that thermophilic bacteria may use elements of LsrB and RbsB operon for AI-2 signal transduction and they may use quorum sensing for purposes like biofilm formation. Nevertheless, thermophiles in which no known quorum sensing system was found may use some unknown mechanisms as the mode of communication. Further information regarding quorum sensing will be explored to develop strategies to disrupt the biofilms of thermophiles.
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Affiliation(s)
- Amandeep Kaur
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Prince Sharma
- Department of Microbiology, Panjab University, Chandigarh, India
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Helicobacter pylori Biofilm Formation and Its Potential Role in Pathogenesis. Microbiol Mol Biol Rev 2018; 82:82/2/e00001-18. [PMID: 29743338 DOI: 10.1128/mmbr.00001-18] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Despite decades of effort, Helicobacter pylori infections remain difficult to treat. Over half of the world's population is infected by H. pylori, which is a major cause of duodenal and gastric ulcers as well as gastric cancer. During chronic infection, H. pylori localizes within the gastric mucosal layer, including deep within invaginations called glands; thanks to its impressive ability to survive despite the harsh acidic environment, it can persist for the host's lifetime. This ability to survive and persist in the stomach is associated with urease production, chemotactic motility, and the ability to adapt to the fluctuating environment. Additionally, biofilm formation has recently been suggested to play a role in colonization. Biofilms are surface-associated communities of bacteria that are embedded in a hydrated matrix of extracellular polymeric substances. Biofilms pose a substantial health risk and are key contributors to many chronic and recurrent infections. This link between biofilm-associated bacteria and chronic infections likely results from an increased tolerance to conventional antibiotic treatments as well as immune system action. The role of this biofilm mode in antimicrobial treatment failure and H. pylori survival has yet to be determined. Furthermore, relatively little is known about the H. pylori biofilm structure or the genes associated with this mode of growth. In this review, therefore, we aim to highlight recent findings concerning H. pylori biofilms and the molecular mechanism of their formation. Additionally, we discuss the potential roles of biofilms in the failure of antibiotic treatment and in infection recurrence.
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Johnson KS, Ottemann KM. Colonization, localization, and inflammation: the roles of H. pylori chemotaxis in vivo. Curr Opin Microbiol 2017; 41:51-57. [PMID: 29202336 DOI: 10.1016/j.mib.2017.11.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/27/2017] [Accepted: 11/16/2017] [Indexed: 12/18/2022]
Abstract
Helicobacter pylori is a Gram-negative bacterium that infects half of the world's population, causing gastritis, peptic ulcers, and gastric cancer. To establish chronic stomach infection, H. pylori utilizes chemotaxis, driven by a conserved signal transduction system. Chemotaxis allows H. pylori to sense an array of environmental and bacterial signals within the stomach, guiding its motility towards its preferred niche within the gastric mucosa and glands. Fine-tuned localization, regulated by the chemotaxis system, enables robust colonization during the acute stage of infection. During chronic infection, chemotaxis helps maintain bacterial populations and modulates the host immune response. Given its importance in host colonization and disease, chemotaxis is an attractive target for future treatments against H. pylori infections.
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Affiliation(s)
- Kevin S Johnson
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
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Jani S, Seely AL, Peabody V GL, Jayaraman A, Manson MD. Chemotaxis to self-generated AI-2 promotes biofilm formation in Escherichia coli. MICROBIOLOGY-SGM 2017; 163:1778-1790. [PMID: 29125461 DOI: 10.1099/mic.0.000567] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Responses to the interspecies quorum-sensing signal autoinducer-2 (AI-2) regulate the patterns of gene expression that promote biofilm development. Escherichia coli also senses AI-2 as a chemoattractant, a response that requires the periplasmic AI-2-binding protein LsrB and the chemoreceptor Tsr. Here, we confirm, as previously observed, that under static conditions highly motile E. coli cells self-aggregate and form surface-adherent structures more readily than cells lacking LsrB and Tsr, or than ΔluxS cells unable to produce AI-2. This difference is observed both at 37 and 30 °C. Cells deleted for the genes encoding the lsrACDBFG operon repressor (ΔlsrR), or the AI-2 kinase (ΔlsrK), or an AI-2 uptake channel protein (ΔlsrC), or an AI-2 metabolism enzyme (ΔlsrG) are also defective in biofilm formation. The Δtsr and ΔlsrB cells are totally defective in AI-2 chemotaxis, whereas the other mutants show normal or near-normal chemotaxis to external gradients of AI-2. These data demonstrate that chemotaxis to external AI-2 is necessary but not sufficient to induce the full range of density-dependent behaviours that are required for optimal biofilm formation. We also demonstrate that, compared to other binding-protein-dependent chemotaxis systems in E. coli, low levels (on the order of ~250 molecules of periplasmic LsrB per wild-type cell and as low as ~50 molecules per cell in some mutants) are adequate for a strong chemotaxis response to external gradients of AI-2.
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Affiliation(s)
- Sneha Jani
- Department of Biology, 3258 TAMU, Texas A&M University, College Station, TX 77843-3258, USA
| | - Andrew L Seely
- Department of Biology, 3258 TAMU, Texas A&M University, College Station, TX 77843-3258, USA
| | - George L Peabody V
- Department of Chemical Engineering, 3122 TAMU, Texas A&M University, College Station, TX 77843-3122, USA
| | - Arul Jayaraman
- Department of Chemical Engineering, 3122 TAMU, Texas A&M University, College Station, TX 77843-3122, USA
| | - Michael D Manson
- Department of Biology, 3258 TAMU, Texas A&M University, College Station, TX 77843-3258, USA
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Krzyżek P, Gościniak G. A proposed role for diffusible signal factors in the biofilm formation and morphological transformation of Helicobacter pylori. TURKISH JOURNAL OF GASTROENTEROLOGY 2017; 29:7-13. [PMID: 29082887 DOI: 10.5152/tjg.2017.17349] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Due to the increasing resistance of Helicobacter pylori to antibiotics, there is a growing need for new strategies for the effective eradication of this pathogen. The inhibition of quorum-sensing activity in most microorganisms leads to a decrease in virulence. A different reaction is observed in H. pylori, as interfering with the production of autoinducer-2 initiates biofilm formation and increases the survival of these bacteria. Therefore, it is believed that there is an alternative way to control the physiological changes of H. pylori exposed to environmental stress. In this article, we present the compounds probably involved in the modulation of H. pylori virulence. Diffusible signal factors (DSFs) are fatty acid signal molecules involved in communication between microbes. DSFs are likely to stimulate H. Pylori transition into a sedentary state that correlates with bacterial transformation into a more resistant coccoid form and initiates biofilm formation. Biofilm is a structure that plays a crucial role in protecting against adverse environmental factors (low pH, oxidative stress, action of immune system) and limiting the effective concentration of antimicrobial substances. This article has suggested and characterized the existence of an alternative DSF-mediated cell-cell signaling of H. pylori, which controls autoaggregative behaviors, biofilm formation, and the transition of microorganisms into the coccoid form.
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Affiliation(s)
- Paweł Krzyżek
- Department of Microbiology, Wroclaw Medical University, Wroclaw, Poland
| | - Grażyna Gościniak
- Department of Microbiology, Wroclaw Medical University, Wroclaw, Poland
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Machuca MA, Johnson KS, Liu YC, Steer DL, Ottemann KM, Roujeinikova A. Helicobacter pylori chemoreceptor TlpC mediates chemotaxis to lactate. Sci Rep 2017; 7:14089. [PMID: 29075010 PMCID: PMC5658362 DOI: 10.1038/s41598-017-14372-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/06/2017] [Indexed: 12/13/2022] Open
Abstract
It is recently appreciated that many bacterial chemoreceptors have ligand-binding domains (LBD) of the dCACHE family, a structure with two PAS-like subdomains, one membrane-proximal and the other membrane-distal. Previous studies had implicated only the membrane-distal subdomain in ligand recognition. Here, we report the 2.2 Å resolution crystal structure of dCACHE LBD of the Helicobacter pylori chemoreceptor TlpC. H. pylori tlpC mutants are outcompeted by wild type during stomach colonisation, but no ligands had been mapped to this receptor. The TlpC dCACHE LBD has two PAS-like subdomains, as predicted. The membrane-distal one possesses a long groove instead of a small, well-defined pocket. The membrane-proximal subdomain, in contrast, had a well-delineated pocket with a small molecule that we identified as lactate. We confirmed that amino acid residues making contact with the ligand in the crystal structure-N213, I218 and Y285 and Y249-were required for lactate binding. We determined that lactate is an H. pylori chemoattractant that is sensed via TlpC with a K D = 155 µM. Lactate is utilised by H. pylori, and our work suggests that this pathogen seeks out lactate using chemotaxis. Furthermore, our work suggests that dCACHE domain proteins can utilise both subdomains for ligand recognition.
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Affiliation(s)
- Mayra A Machuca
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Kevin S Johnson
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Yu C Liu
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - David L Steer
- Monash Biomedical Proteomics Facility, Monash University, Clayton, Victoria, 3800, Australia
| | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA.
| | - Anna Roujeinikova
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia.
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46
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Abstract
Chemoreceptors in bacteria detect a variety of signals and feed this information into chemosensory pathways that represent a major mode of signal transduction. The five chemoreceptors from Escherichia coli have served as traditional models in the study of this protein family. Genome analyses revealed that many bacteria contain much larger numbers of chemoreceptors with broader sensory capabilities. Chemoreceptors differ in topology, sensing mode, cellular location, and, above all, the type of ligand binding domain (LBD). Here, we highlight LBD diversity using well-established and emerging model organisms as well as genomic surveys. Nearly a hundred different types of protein domains that are found in chemoreceptor sequences are known or predicted LBDs, but only a few of them are ubiquitous. LBDs of the same class recognize different ligands, and conversely, the same ligand can be recognized by structurally different LBDs; however, recent studies began to reveal common characteristics in signal-LBD relationships. Although signals can stimulate chemoreceptors in a variety of different ways, diverse LBDs appear to employ a universal transmembrane signaling mechanism. Current and future studies aim to establish relationships between LBD types, the nature of signals that they recognize, and the mechanisms of signal recognition and transduction.
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47
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Lee AY, Kao CY, Wang YK, Lin SY, Lai TY, Sheu BS, Lo CJ, Wu JJ. Inactivation of ferric uptake regulator (Fur) attenuates Helicobacter pylori J99 motility by disturbing the flagellar motor switch and autoinducer-2 production. Helicobacter 2017; 22. [PMID: 28402041 DOI: 10.1111/hel.12388] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Flagellar motility of Helicobacter pylori has been shown to be important for the bacteria to establish initial colonization. The ferric uptake regulator (Fur) is a global regulator that has been identified in H. pylori which is involved in the processes of iron uptake and establishing colonization. However, the role of Fur in H. pylori motility is still unclear. MATERIALS AND METHODS Motility of the wild-type, fur mutant, and fur revertant J99 were determined by a soft-agar motility assay and direct video observation. The bacterial shape and flagellar structure were evaluated by transmission electron microscopy. Single bacterial motility and flagellar switching were observed by phase-contrast microscopy. Autoinducer-2 (AI-2) production in bacterial culture supernatant was analyzed by a bioluminescence assay. RESULTS The fur mutant showed impaired motility in the soft-agar assay compared with the wild-type J99 and fur revertant. The numbers and lengths of flagellar filaments on the fur mutant cells were similar to those of the wild-type and revertant cells. Phenotypic characterization showed similar swimming speed but reduction in switching rate in the fur mutant. The AI-2 production of the fur mutant was dramatically reduced compared with wild-type J99 in log-phase culture medium. CONCLUSIONS These results indicate that Fur positively modulates H. pylori J99 motility through interfering with bacterial flagellar switching.
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Affiliation(s)
- Ai-Yun Lee
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Cheng-Yen Kao
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University, Taipei, Taiwan
| | - Yao-Kuan Wang
- Department of Physics and Graduate Institute of Biophysics, National Central University, Jhongli, Taiwan
| | - Ssu-Yuan Lin
- Department of Physics and Graduate Institute of Biophysics, National Central University, Jhongli, Taiwan
| | - Tze-Ying Lai
- Department of Physics and Graduate Institute of Biophysics, National Central University, Jhongli, Taiwan
| | - Bor-Shyang Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Internal Medicine, Tainan Hospital, Ministry of Health & Welfare, Taiwan
| | - Chien-Jung Lo
- Department of Physics and Graduate Institute of Biophysics, National Central University, Jhongli, Taiwan
| | - Jiunn-Jong Wu
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University, Taipei, Taiwan
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Abstract
BACKGROUND Helicobacter pylori is well adapted to colonize the epithelial surface of the human gastric mucosa and can cause persistent infections. In order to infect the gastric mucosa, it has to survive in the gastric acidic pH. This organism has well developed mechanisms to neutralize the effects of acidic pH. OBJECTIVE This review article was designed to summarize the various functional and molecular aspects by which the bacterium can combat and survive the gastric acidic pH in order to establish the persistent infections. METHODS We used the keywords (acid acclimation, gastric acidic environment, H. pylori and survival) in combination or alone for pubmed search of recent scientific literatures. One hundred and forty one papers published between 1989 and 2016 were sorted out. The articles published with only abstracts, other than in English language, case reports and reviews were excluded. RESULTS Many literatures describing the role of several factors in acid survival were found. Recently, the role of several other factors has been claimed to participate in acid survival. CONCLUSION In conclusion, this organism has well characterized mechanisms for acid survival.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan,Department of Medicine-Gastroenterology, Baylor College of Medicine, Houston, Texas, USA,Corresponding author: Yoshio Yamaoka, MD, PhD, Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu-City, Oita 879-5593, Japan, Tel: +81-97-586-5740; Fax: +81-97-586-5749,
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49
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Abstract
Bacterial pathogens must endure or adapt to different environments and stresses during transmission and infection. Posttranscriptional gene expression control by regulatory RNAs, such as small RNAs and riboswitches, is now considered central to adaptation in many bacteria, including pathogens. The study of RNA-based regulation (riboregulation) in pathogenic species has provided novel insight into how these bacteria regulate virulence gene expression. It has also uncovered diverse mechanisms by which bacterial small RNAs, in general, globally control gene expression. Riboregulators as well as their targets may also prove to be alternative targets or provide new strategies for antimicrobials. In this article, we present an overview of the general mechanisms that bacteria use to regulate with RNA, focusing on examples from pathogens. In addition, we also briefly review how deep sequencing approaches have aided in opening new perspectives in small RNA identification and the study of their functions. Finally, we discuss examples of riboregulators in two model pathogens that control virulence factor expression or survival-associated phenotypes, such as stress tolerance, biofilm formation, or cell-cell communication, to illustrate how riboregulation factors into regulatory networks in bacterial pathogens.
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50
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Chandrashekhar K, Kassem II, Rajashekara G. Campylobacter jejuni transducer like proteins: Chemotaxis and beyond. Gut Microbes 2017; 8:323-334. [PMID: 28080213 PMCID: PMC5570417 DOI: 10.1080/19490976.2017.1279380] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 12/12/2016] [Accepted: 12/29/2016] [Indexed: 02/03/2023] Open
Abstract
Chemotaxis, a process that mediates directional motility toward or away from chemical stimuli (chemoeffectors/ligands that can be attractants or repellents) in the environment, plays an important role in the adaptation of Campylobacter jejuni to disparate niches. The chemotaxis system consists of core signal transduction proteins and methyl-accepting-domain-containing Transducer like proteins (Tlps). Ligands binding to Tlps relay a signal to chemotaxis proteins in the cytoplasm which initiate a signal transduction cascade, culminating into a directional flagellar movement. Tlps facilitate substrate-specific chemotaxis in C. jejuni, which plays an important role in the pathogen's adaptation, pathobiology and colonization of the chicken gastrointestinal tract. However, the role of Tlps in C. jejuni's host tissue specific colonization, physiology and virulence remains not completely understood. Based on recent studies, it can be predicted that Tlps might be important targets for developing strategies to control C. jejuni via vaccines and antimicrobials.
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Affiliation(s)
- Kshipra Chandrashekhar
- Department of Food Animal Health and Preventive Medicine, Ohio Agricultural Research and Development Center, Ohio State University, Wooster, Ohio, USA
| | - Issmat I. Kassem
- Department of Food Animal Health and Preventive Medicine, Ohio Agricultural Research and Development Center, Ohio State University, Wooster, Ohio, USA
| | - Gireesh Rajashekara
- Department of Food Animal Health and Preventive Medicine, Ohio Agricultural Research and Development Center, Ohio State University, Wooster, Ohio, USA
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