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Yamaoka Y, Saruuljavkhlan B, Alfaray RI, Linz B. Pathogenomics of Helicobacter pylori. Curr Top Microbiol Immunol 2023; 444:117-155. [PMID: 38231217 DOI: 10.1007/978-3-031-47331-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The human stomach bacterium Helicobacter pylori, the causative agent of gastritis, ulcers and adenocarcinoma, possesses very high genetic diversity. H. pylori has been associated with anatomically modern humans since their origins over 100,000 years ago and has co-evolved with its human host ever since. Predominantly intrafamilial and local transmission, along with genetic isolation, genetic drift, and selection have facilitated the development of distinct bacterial populations that are characteristic for large geographical areas. H. pylori utilizes a large arsenal of virulence and colonization factors to mediate the interaction with its host. Those include various adhesins, the vacuolating cytotoxin VacA, urease, serine protease HtrA, the cytotoxin-associated genes pathogenicity island (cagPAI)-encoded type-IV secretion system and its effector protein CagA, all of which contribute to disease development. While many pathogenicity-related factors are present in all strains, some belong to the auxiliary genome and are associated with specific phylogeographic populations. H. pylori is naturally competent for DNA uptake and recombination, and its genome evolution is driven by extraordinarily high recombination and mutation rates that are by far exceeding those in other bacteria. Comparative genome analyses revealed that adaptation of H. pylori to individual hosts is associated with strong selection for particular protein variants that facilitate immune evasion, especially in surface-exposed and in secreted virulence factors. Recent studies identified single-nucleotide polymorphisms (SNPs) in H. pylori that are associated with the development of severe gastric disease, including gastric cancer. Here, we review the current knowledge about the pathogenomics of H. pylori.
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Affiliation(s)
- Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1, Idaigaoka, Hasama-machi, Yufu Oita, 879-5593, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Batsaikhan Saruuljavkhlan
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1, Idaigaoka, Hasama-machi, Yufu Oita, 879-5593, Japan
| | - Ricky Indra Alfaray
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1, Idaigaoka, Hasama-machi, Yufu Oita, 879-5593, Japan
- Helicobacter pylori and Microbiota Study Group, Universitas Airlangga, Surabaya, 60286, East Java, Indonesia
| | - Bodo Linz
- Division of Microbiology, Department Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058, Erlangen, Germany.
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2
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Thorpe HA, Tourrette E, Yahara K, Vale FF, Liu S, Oleastro M, Alarcon T, Perets TT, Latifi-Navid S, Yamaoka Y, Martinez-Gonzalez B, Karayiannis I, Karamitros T, Sgouras DN, Elamin W, Pascoe B, Sheppard SK, Ronkainen J, Aro P, Engstrand L, Agreus L, Suerbaum S, Thorell K, Falush D. Repeated out-of-Africa expansions of Helicobacter pylori driven by replacement of deleterious mutations. Nat Commun 2022; 13:6842. [PMID: 36369175 PMCID: PMC9652371 DOI: 10.1038/s41467-022-34475-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022] Open
Abstract
Helicobacter pylori lives in the human stomach and has a population structure resembling that of its host. However, H. pylori from Europe and the Middle East trace substantially more ancestry from modern African populations than the humans that carry them. Here, we use a collection of Afro-Eurasian H. pylori genomes to show that this African ancestry is due to at least three distinct admixture events. H. pylori from East Asia, which have undergone little admixture, have accumulated many more non-synonymous mutations than African strains. European and Middle Eastern bacteria have elevated African ancestry at the sites of these mutations, implying selection to remove them during admixture. Simulations show that population fitness can be restored after bottlenecks by migration and subsequent admixture of small numbers of bacteria from non-bottlenecked populations. We conclude that recent spread of African DNA has been driven by deleterious mutations accumulated during the original out-of-Africa bottleneck.
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Affiliation(s)
- Harry A Thorpe
- Department of Biostatistics, University of Oslo, Oslo, Norway
| | - Elise Tourrette
- CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Koji Yahara
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Filipa F Vale
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Siqi Liu
- CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Mónica Oleastro
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health Dr Ricardo Jorge, Lisbon, Portugal
| | - Teresa Alarcon
- Department of Microbiology, Hospital Universitario La Princesa, Instituto de Investigación Sanitaria Princesa, Madrid, Spain
| | - Tsachi-Tsadok Perets
- Gastroenterology Laboratory, Rabin Medical Center, Petah Tikva, Israel
- Department of Digital Medical Technologies, Holon Institute of Technology, Holon, Israel
| | - Saeid Latifi-Navid
- Department of Biology, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Oita, Japan
- Department of Medicine-Gastroenterology, Baylor College of Medicine, Houston, TX, USA
| | | | - Ioannis Karayiannis
- Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece
| | | | | | - Wael Elamin
- G42 Healthcare, Abu Dhabi, UAE
- Elrazi University, Khartoum, Sudan
| | - Ben Pascoe
- Department of Biology, University of Oxford, Oxford, UK
| | - Samuel K Sheppard
- Ineos Oxford Institute, Department of Biology, University of Oxford, Oxford, UK
| | - Jukka Ronkainen
- Center for Life Course Health Research, University of Oulu, Oulu, Finland
- Primary Health Care Center, Tornio, Finland
| | | | - Lars Engstrand
- Center for Translational Microbiome Research, Department for Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Lars Agreus
- Division of Family Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Sebastian Suerbaum
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Munich, Germany
- Department of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hanover, Germany
- DZIF German Center for Infection Research, Hannover-Braunschweig and Munich Partner Sites, Munich, Germany
| | - Kaisa Thorell
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Daniel Falush
- CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
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3
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Biomarker Characterization and Prediction of Virulence and Antibiotic Resistance from Helicobacter pylori Next Generation Sequencing Data. Biomolecules 2022; 12:biom12050691. [PMID: 35625618 PMCID: PMC9138241 DOI: 10.3390/biom12050691] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/02/2022] [Accepted: 05/07/2022] [Indexed: 02/06/2023] Open
Abstract
The Gram-negative bacterium Helicobacter pylori colonizes c.a. 50% of human stomachs worldwide and is the major risk factor for gastric adenocarcinoma. Its high genetic variability makes it difficult to identify biomarkers of early stages of infection that can reliably predict its outcome. Moreover, the increasing antibiotic resistance found in H. pylori defies therapy, constituting a major human health problem. Here, we review H. pylori virulence factors and genes involved in antibiotic resistance, as well as the technologies currently used for their detection. Furthermore, we show that next generation sequencing may lead to faster characterization of virulence factors and prediction of the antibiotic resistance profile, thus contributing to personalized treatment and management of H. pylori-associated infections. With this new approach, more and permanent data will be generated at a lower cost, opening the future to new applications for H. pylori biomarker identification and antibiotic resistance prediction.
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CagL polymorphisms between East Asian and Western Helicobacter pylori are associated with different abilities to induce IL-8 secretion. J Microbiol 2021; 59:763-770. [PMID: 34061339 DOI: 10.1007/s12275-021-1136-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 12/17/2022]
Abstract
Helicobacter pylori colonizes human gastric mucosa. Its infection is associated with gastric diseases including gastric cancer. CagA is one of the most important toxins produced by H. pylori. It is related to gastric cancer which can be injected into host cells via a type IV secretion system (T4SS). CagL is a structural component of T4SS apparatus, which triggers host cell signaling pathway. It has been reported that CagL polymorphisms may influence the severity of disease development. To explore the contribution of CagL polymorphisms between East Asian and Western H. pylori in pathogenesis, cagL gene in G27 H. pylori was swapped by K74 cagL which is identical to East Asian CagL consensus sequence and by Western 26695 H. pylori, resulting in G27 ΔcagL/cagLK74 and G27 ΔcagL/cagL26695, respectively. Intriguingly, G27 ΔcagL/cagLK74 showed significantly less ability of IL-8 induction than G27 ΔcagL/cagL26695 while displayed similar abilities of CagA phosphorylation, and cell elongation. Taken together, this study suggests that the CagL polymorphism may influence IL-8 induction, and K74 CagL has less ability to induce IL-8 secretion than G27 or 26695 CagL. Further research should address how the different capabilities of IL-8 induction between intraspecies-CagL are associated with the large differences of the incidence of gastric cancer between East Asian and Western countries.
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Zhao Q, Song C, Wang K, Li D, Yang Y, Liu D, Wang L, Zhou N, Xie Y. Prevalence of Helicobacter pylori babA, oipA, sabA, and homB genes in isolates from Chinese patients with different gastroduodenal diseases. Med Microbiol Immunol 2020; 209:565-577. [PMID: 32219508 DOI: 10.1007/s00430-020-00666-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/16/2020] [Indexed: 02/06/2023]
Abstract
Disease outcome is associated with virulence factors of Helicobacter pylori (H. pylori), which are partially attributed to the outer membrane protein (OMP). This study aimed to investigate the correlation between the four OMP genes (babA, oipA, sabA, and homB) and gastroduodenal diseases. One hundred and seventy-seven H. pylori strains were isolated from Chinese patients with different gastroduodenal diseases (49 chronic gastritis, 19 gastric ulcer, 33 gastric cancer, and 76 duodenal ulcer), 94 of which contained pathological information (41 superficial gastritis, 24 intestinal hyperplasia, and 29 gastric adenocarcinoma). The full-length amplification of babA, oipA, sabA, and homB genes was acquired and sequenced. Then, the genetic polymorphism was analyzed to compare with the reference strains from the GenBank database. Functional status and cluster analysis were also performed to evaluate the impact of genetic polymorphism on disease outcome. The prevalence of babA, oipA, sabA, and homB genes were 91.5%, 100%, 94.0%, and 95.5%, respectively. The four OMP genes were characterized by genetic polymorphism and in the status of positive selection (Ka/Ks> 1). The proportion of strains with functional status on for oipA and sabA gene was 100% and 76.2%, respectively. The sequences of four OMP genes were mainly clustered together with the East Asian references. The four OMP genes were not different in patients with gastroduodenal diseases and pathologic changes (P > 0.05). H. pylori babA, oipA, sabA, and homB genes were common in the Chinese populations, but did not seem to be involved in the development of gastroduodenal diseases.
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Affiliation(s)
- Qiaoyun Zhao
- Department of Gastroenterology, First Affiliated Hospital of Nanchang University, No.17 Yongwaizheng Street, Donghu District, Nanchang, 330006, Jiangxi, China.,Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Conghua Song
- Department of Gastroenterology, First Affiliated Hospital of Nanchang University, No.17 Yongwaizheng Street, Donghu District, Nanchang, 330006, Jiangxi, China.,Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Department of Gastroenterology, Affiliated Hospital of Putian University, Putian, 351100, Fujian, China
| | - Ke Wang
- Laboratory of Biochemistry and Molecular Biology, Jiangxi Institute of Medical Sciences, Nanchang, 330006, Jiangxi, China
| | - Donghong Li
- Laboratory of Biochemistry and Molecular Biology, Jiangxi Institute of Medical Sciences, Nanchang, 330006, Jiangxi, China
| | - Yang Yang
- Department of Gastroenterology, First Affiliated Hospital of Nanchang University, No.17 Yongwaizheng Street, Donghu District, Nanchang, 330006, Jiangxi, China.,Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Dongsheng Liu
- Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Le Wang
- Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Nanjin Zhou
- Laboratory of Biochemistry and Molecular Biology, Jiangxi Institute of Medical Sciences, Nanchang, 330006, Jiangxi, China
| | - Yong Xie
- Department of Gastroenterology, First Affiliated Hospital of Nanchang University, No.17 Yongwaizheng Street, Donghu District, Nanchang, 330006, Jiangxi, China. .,Microbiology Laboratory, Gastroenterology Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China. .,Gastroenterology Research Center, Key Laboratory of Digestive Diseases of Jiangxi Province, Nanchang, 330006, Jiangxi, China.
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6
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García-Zea JA, de la Herrán R, Robles Rodríguez F, Navajas-Pérez R, Ruiz Rejón C. Detection and variability analyses of CRISPR-like loci in the H. pylori genome. PeerJ 2019; 7:e6221. [PMID: 30648020 PMCID: PMC6330956 DOI: 10.7717/peerj.6221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori is a human pathogenic bacterium with a high genomic plasticity. Although the functional CRISPR-Cas system has not been found in its genome, CRISPR-like loci have been recently identified. In this work, 53 genomes from different geographical areas are analyzed for the search and analysis of variability of this type of structure. We confirm the presence of a locus that was previously described in the VlpC gene in al lgenomes, and we characterize new CRISPR-like loci in other genomic locations. By studying the variability and gene location of these loci, the evolution and the possible roles of these sequences are discussed. Additionally, the usefulness of this type of sequences as a phylogenetic marker has been demonstrated, associating the different strains by geographical area.
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Affiliation(s)
| | - Roberto de la Herrán
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | | | - Rafael Navajas-Pérez
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Carmelo Ruiz Rejón
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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7
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Bravo D, Hoare A, Soto C, Valenzuela MA, Quest AFG. Helicobacter pylori in human health and disease: Mechanisms for local gastric and systemic effects. World J Gastroenterol 2018; 24:3071-3089. [PMID: 30065554 PMCID: PMC6064966 DOI: 10.3748/wjg.v24.i28.3071] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/17/2018] [Accepted: 06/27/2018] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) is present in roughly 50% of the human population worldwide and infection levels reach over 70% in developing countries. The infection has classically been associated with different gastro-intestinal diseases, but also with extra gastric diseases. Despite such associations, the bacterium frequently persists in the human host without inducing disease, and it has been suggested that H. pylori may also play a beneficial role in health. To understand how H. pylori can produce such diverse effects in the human host, several studies have focused on understanding the local and systemic effects triggered by this bacterium. One of the main mechanisms by which H. pylori is thought to damage the host is by inducing local and systemic inflammation. However, more recently, studies are beginning to focus on the effects of H. pylori and its metabolism on the gastric and intestinal microbiome. The objective of this review is to discuss how H. pylori has co-evolved with humans, how H. pylori presence is associated with positive and negative effects in human health and how inflammation and/or changes in the microbiome are associated with the observed outcomes.
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Affiliation(s)
- Denisse Bravo
- Oral Microbiology Laboratory, Pathology and Oral Medicine Department, Faculty of Dentistry, Universidad de Chile, Santiago 8380492, Chile
| | - Anilei Hoare
- Oral Microbiology Laboratory, Pathology and Oral Medicine Department, Faculty of Dentistry, Universidad de Chile, Santiago 8380492, Chile
| | - Cristopher Soto
- Oral Microbiology Laboratory, Pathology and Oral Medicine Department, Faculty of Dentistry, Universidad de Chile, Santiago 8380492, Chile
| | - Manuel A Valenzuela
- Advanced Center for Chronic Diseases, Institute for Health-Related Research and Innovation, Faculty of Health Sciences, Universidad Central de Chile, Santiago 8380447, Chile
| | - Andrew FG Quest
- Advanced Center for Chronic Diseases, Center for Studies on Exercise, Metabolism and Cancer, Biomedical Science Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380447, Chile
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8
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Bullock KK, Shaffer CL, Brooks AW, Secka O, Forsyth MH, McClain MS, Cover TL. Genetic signatures for Helicobacter pylori strains of West African origin. PLoS One 2017; 12:e0188804. [PMID: 29186206 PMCID: PMC5706691 DOI: 10.1371/journal.pone.0188804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 11/13/2017] [Indexed: 01/22/2023] Open
Abstract
Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of H. pylori strains from seven globally distributed populations or subpopulations and identified encoded proteins that exhibited the highest levels of sequence divergence. These included secreted proteins, an LPS glycosyltransferase, fucosyltransferases, proteins involved in molybdopterin biosynthesis, and Clp protease adaptor (ClpS). Among proteins encoded by the cag pathogenicity island, CagA and CagQ exhibited the highest levels of sequence diversity. We then identified proteins in strains of Western African origin (classified as hspWAfrica by MLST analysis) with sequences that were highly divergent compared to those in other populations of strains. These included ATP-dependent Clp protease, ClpS, and proteins of unknown function. Three of the divergent proteins sequences identified in West African strains were characterized by distinct insertions or deletions up to 8 amino acids in length. These polymorphisms in rapidly evolving proteins represent robust genetic signatures for H. pylori strains of West African origin.
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Affiliation(s)
- Kennady K. Bullock
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Carrie L. Shaffer
- Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, United States of America
| | - Andrew W. Brooks
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Ousman Secka
- Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Mark H. Forsyth
- Department of Biology, The College of William and Mary, Williamsburg, Virginia, United States of America
| | - Mark S. McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Timothy L. Cover
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, United States of America
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Kumar N, Albert MJ, Al Abkal H, Siddique I, Ahmed N. What constitutes an Arabian Helicobacter pylori? Lessons from comparative genomics. Helicobacter 2017; 22. [PMID: 27277215 DOI: 10.1111/hel.12323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Helicobacter pylori, the human gastric pathogen, causes a variety of gastric diseases ranging from mild gastritis to gastric cancer. While the studies on H. pylori are dominated by those based on either East Asian or Western strains, information regarding H. pylori strains prevalent in the Middle East remains scarce. Therefore, we carried out whole-genome sequencing and comparative analysis of three H. pylori strains isolated from three native Arab, Kuwaiti patients. MATERIALS AND METHODS H. pylori strains were sequenced using Illumina platform. The sequence reads were filtered and draft genomes were assembled and annotated. Various pathogenicity-associated regions and phages present within the genomes were identified. Phylogenetic analysis was carried out to determine the genetic relatedness of Kuwaiti strains to various lineages of H. pylori. The core genome content and virulence-related genes were analyzed to assess the pathogenic potential. RESULTS The three genomes clustered along with HpEurope strains in the phylogenetic tree comprising various H. pylori lineages. A total of 1187 genes spread among various functional classes were identified in the core genome analysis. The three genomes possessed a complete cagPAI and also retained most of the known outer membrane proteins as well as virulence-related genes. The cagA gene in all three strains consisted of an AB-C type EPIYA motif. CONCLUSIONS The comparative genomic analysis of Kuwaiti H. pylori strains revealed a European ancestry and a high pathogenic potential.
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Affiliation(s)
- Narender Kumar
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, Telangana, India
| | - M John Albert
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Hanan Al Abkal
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Iqbal Siddique
- Department of Medicine, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Niyaz Ahmed
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, Telangana, India
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10
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Kumar A, Manivelan V, Bansal M. Structural features of DNA are conserved in the promoter region of orthologous genes across different strains ofHelicobacter pylori. FEMS Microbiol Lett 2016; 363:fnw207. [DOI: 10.1093/femsle/fnw207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2016] [Indexed: 12/19/2022] Open
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11
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Foegeding NJ, Caston RR, McClain MS, Ohi MD, Cover TL. An Overview of Helicobacter pylori VacA Toxin Biology. Toxins (Basel) 2016; 8:toxins8060173. [PMID: 27271669 PMCID: PMC4926140 DOI: 10.3390/toxins8060173] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/18/2016] [Accepted: 05/27/2016] [Indexed: 12/11/2022] Open
Abstract
The VacA toxin secreted by Helicobacter pylori enhances the ability of the bacteria to colonize the stomach and contributes to the pathogenesis of gastric adenocarcinoma and peptic ulcer disease. The amino acid sequence and structure of VacA are unrelated to corresponding features of other known bacterial toxins. VacA is classified as a pore-forming toxin, and many of its effects on host cells are attributed to formation of channels in intracellular sites. The most extensively studied VacA activity is its capacity to stimulate vacuole formation, but the toxin has many additional effects on host cells. Multiple cell types are susceptible to VacA, including gastric epithelial cells, parietal cells, T cells, and other types of immune cells. This review focuses on the wide range of VacA actions that are detectable in vitro, as well as actions of VacA in vivo that are relevant for H. pylori colonization of the stomach and development of gastric disease.
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Affiliation(s)
- Nora J Foegeding
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Rhonda R Caston
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Mark S McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Melanie D Ohi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Timothy L Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
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12
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Abstract
Gastric cancer is a leading cause of cancer-related death worldwide. Helicobacter pylori infection is the strongest known risk factor for this malignancy. An important goal is to identify H. pylori-infected persons at high risk for gastric cancer, so that these individuals can be targeted for therapeutic intervention. H. pylori exhibits a high level of intraspecies genetic diversity, and over the past two decades, many studies have endeavored to identify strain-specific features of H. pylori that are linked to development of gastric cancer. One of the most prominent differences among H. pylori strains is the presence or absence of a 40-kb chromosomal region known as the cag pathogenicity island (PAI). Current evidence suggests that the risk of gastric cancer is very low among persons harboring H. pylori strains that lack the cag PAI. Among persons harboring strains that contain the cag PAI, the risk of gastric cancer is shaped by a complex interplay among multiple strain-specific bacterial factors as well as host factors. This review discusses the strain-specific properties of H. pylori that correlate with increased gastric cancer risk, focusing in particular on secreted proteins and surface-exposed proteins, and describes evidence from cell culture and animal models linking these factors to gastric cancer pathogenesis. Strain-specific features of H. pylori that may account for geographic variation in gastric cancer incidence are also discussed.
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13
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Worldwide Population Structure, Long-Term Demography, and Local Adaptation of Helicobacter pylori. Genetics 2015; 200:947-63. [PMID: 25995212 DOI: 10.1534/genetics.115.176404] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/15/2015] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori is an important human pathogen associated with serious gastric diseases. Owing to its medical importance and close relationship with its human host, understanding genomic patterns of global and local adaptation in H. pylori may be of particular significance for both clinical and evolutionary studies. Here we present the first such whole genome analysis of 60 globally distributed strains, from which we inferred worldwide population structure and demographic history and shed light on interesting global and local events of positive selection, with particular emphasis on the evolution of San-associated lineages. Our results indicate a more ancient origin for the association of humans and H. pylori than previously thought. We identify several important perspectives for future clinical research on candidate selected regions that include both previously characterized genes (e.g., transcription elongation factor NusA and tumor necrosis factor alpha-inducing protein Tipα) and hitherto unknown functional genes.
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You Y, He L, Zhang M, Zhang J. Comparative genomics of a Helicobacter pylori isolate from a Chinese Yunnan Naxi ethnic aborigine suggests high genetic divergence and phage insertion. PLoS One 2015; 10:e0120659. [PMID: 25799515 PMCID: PMC4370579 DOI: 10.1371/journal.pone.0120659] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 01/07/2015] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a common pathogen correlated with several severe digestive diseases. It has been reported that isolates associated with different geographic areas, different diseases and different individuals might have variable genomic features. Here, we describe draft genomic sequences of H. pylori strains YN4-84 and YN1-91 isolated from patients with gastritis from the Naxi and Han populations of Yunnan, China, respectively. The draft sequences were compared to 45 other publically available genomes, and a total of 1059 core genes were identified. Genes involved in restriction modification systems, type four secretion system three (TFS3) and type four secretion system four (TFS4), were identified as highly divergent. Both YN4-84 and YN1-91 harbor intact cag pathogenicity island (cagPAI) and have EPIYA-A/B/D type at the carboxyl terminal of cagA. The vacA gene type is s1m2i1. Another major finding was a 32.5-kb prophage integrated in the YN4-84 genome. The prophage shares most of its genes (30/33) with Helicobacter pylori prophage KHP30. Moreover, a 1,886 bp transposable sequence (IS605) was found in the prophage. Our results imply that the Naxi ethnic minority isolate YN4-84 and Han isolate YN1-91 belong to the hspEAsia subgroup and have diverse genome structure. The genome has been extensively modified in several regions involved in horizontal DNA transfer. The important roles played by phages in the ecology and microevolution of H. pylori were further emphasized. The current data will provide valuable information regarding the H. pylori genome based on historic human migrations and population structure.
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Affiliation(s)
- Yuanhai You
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, China
| | - Lihua He
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, China
| | - Maojun Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, China
| | - Jianzhong Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, China
- * E-mail:
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15
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Wang J, Sun Y, Bertagnolli MM. Comparison of gastric cancer survival between Caucasian and Asian patients treated in the United States: results from the Surveillance Epidemiology and End Results (SEER) database. Ann Surg Oncol 2015; 22:2965-71. [PMID: 25631065 DOI: 10.1245/s10434-015-4388-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The prognosis for gastric cancer is better for Asian than for Caucasian patients. The primary driver of this difference is unknown. This study determined whether the survival advantage of Asian ethnicity continued to hold after control was used for other well-known prognostic factors. METHODS In this study, 12,773 patients who underwent gastrectomy for treatment of adenocarcinoma of the stomach were identified from the Surveillance, Epidemiology, and End Results cancer registry. Patients with cardia tumor were excluded from the study. The independent prognostic effect of ethnicity was evaluated by adjusting for other known factors. RESULTS The Asian patients tended to have a diagnosis at an earlier age (66.8 vs. 68.5 years), more lymph nodes examined (16 vs. 13), and more positive lymph nodes (5.1 vs. 4.8). Survival was better for the Asian patients than for the Caucasian patients, with a 12 % 5-year survival difference. Among the patients with IB, IIA, and IIB disease, the Asian patients had 37, 72, and 13 months longer median survival time than the corresponding Caucasian patients. The multivariate Cox model showed persistence of this result after adjustment for imbalances of age, gender, tumor grade, and number of examined and positive lymph nodes. The largest risk reduction was observed for the stage IA patients (31 %) and the smallest for the stage IIIC patients (9 %). CONCLUSION After excluding proximal gastric cancers, controlling for the imbalance of known prognostic factors, and decreasing in the influence of D2 lymphadenectomy, stage migration, and chemo/radiation therapy by including only patients treated in the United States, this study found that the survival advantage of Asian ethnicity continued to be present.
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Affiliation(s)
- Jiping Wang
- Division of Surgical Oncology, Brigham and Women's Hospital, Boston, MA, USA,
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Kumar N, Mariappan V, Baddam R, Lankapalli AK, Shaik S, Goh KL, Loke MF, Perkins T, Benghezal M, Hasnain SE, Vadivelu J, Marshall BJ, Ahmed N. Comparative genomic analysis of Helicobacter pylori from Malaysia identifies three distinct lineages suggestive of differential evolution. Nucleic Acids Res 2014; 43:324-35. [PMID: 25452339 PMCID: PMC4288169 DOI: 10.1093/nar/gku1271] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The discordant prevalence of Helicobacter pylori and its related diseases, for a long time, fostered certain enigmatic situations observed in the countries of the southern world. Variation in H. pylori infection rates and disease outcomes among different populations in multi-ethnic Malaysia provides a unique opportunity to understand dynamics of host–pathogen interaction and genome evolution. In this study, we extensively analyzed and compared genomes of 27 Malaysian H. pylori isolates and identified three major phylogeographic lineages: hspEastAsia, hpEurope and hpSouthIndia. The analysis of the virulence genes within the core genome, however, revealed a comparable pathogenic potential of the strains. In addition, we identified four genes limited to strains of East-Asian lineage. Our analyses identified a few strain-specific genes encoding restriction modification systems and outlined 311 core genes possibly under differential evolutionary constraints, among the strains representing different ethnic groups. The cagA and vacA genes also showed variations in accordance with the host genetic background of the strains. Moreover, restriction modification genes were found to be significantly enriched in East-Asian strains. An understanding of these variations in the genome content would provide significant insights into various adaptive and host modulation strategies harnessed by H. pylori to effectively persist in a host-specific manner.
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Affiliation(s)
- Narender Kumar
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Ramani Baddam
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Aditya K Lankapalli
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Sabiha Shaik
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Khean-Lee Goh
- Department of Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Mun Fai Loke
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Tim Perkins
- School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Mohammed Benghezal
- School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Seyed E Hasnain
- Kusuma School of Biological Sciences, Indian Institute of Technology, Hauz Khas, New Delhi, 110016, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Barry J Marshall
- School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Niyaz Ahmed
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Gachibowli, Hyderabad, 500046, India Institute of Biological Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia
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Lin D, Koskella B. Friend and foe: factors influencing the movement of the bacterium Helicobacter pylori along the parasitism-mutualism continuum. Evol Appl 2014; 8:9-22. [PMID: 25667600 PMCID: PMC4310578 DOI: 10.1111/eva.12231] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/14/2014] [Indexed: 12/11/2022] Open
Abstract
Understanding the transition of bacterial species from commensal to pathogen, or vice versa, is a key application of evolutionary theory to preventative medicine. This requires working knowledge of the molecular interaction between hosts and bacteria, ecological interactions among microbes, spatial variation in bacterial prevalence or host life history, and evolution in response to these factors. However, there are very few systems for which such broad datasets are available. One exception is the gram-negative bacterium, Helicobacter pylori, which infects upwards of 50% of the global human population. This bacterium is associated with a wide breadth of human gastrointestinal disease, including numerous cancers, inflammatory disorders, and pathogenic infections, but is also known to confer fitness benefits to its host both indirectly, through interactions with other pathogens, and directly. Outstanding questions are therefore why, when, and how this bacterium transitions along the parasitism–mutualism continuum. We examine known virulence factors, genetic predispositions of the host, and environmental contributors that impact progression of clinical disease and help define geographical trends in disease incidence. We also highlight the complexity of the interaction and discuss future therapeutic strategies for disease management and public health in light of the longstanding evolutionary history between the bacterium and its human host.
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Merchant SJ, Li L, Kim J. Racial and ethnic disparities in gastric cancer outcomes: More important than surgical technique? World J Gastroenterol 2014; 20:11546-11551. [PMID: 25206261 PMCID: PMC4155347 DOI: 10.3748/wjg.v20.i33.11546] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/08/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Racial and ethnic disparities in cancer care are major public health concerns and their identification is necessary to develop interventions to eliminate these disparities. We and others have previously observed marked disparities in gastric cancer outcomes between Eastern and Western patients. These disparities have long been attributed to surgical technique and extent of lymphadenectomy. However, more recent evidence suggests that other factors such as tumor biology, environmental factors such as Helicobacter pylori infection and stage migration may also significantly contribute to these observed disparities. We review the literature surrounding disparities in gastric cancer and provide data pertaining to potential contributing factors.
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Abstract
The present manuscript focuses on the new information that was published in the field of diagnosis of Helicobacter pylori this past year. While there is little news about the invasive tests, more data are coming concerning the endoscopic features of H. pylori infection. Major efforts were also done to improve molecular detection of the mutations involved in antibiotic resistance. New antibody-based tests (stool antigen test or indirect antibody tests) were also developed.
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Affiliation(s)
- Francis Mégraud
- Laboratoire de bactériologie, Université de Bordeaux, 33076, Bordeaux, France; INSERM U853, 33076, Bordeaux, France
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Fischer W, Breithaupt U, Kern B, Smith SI, Spicher C, Haas R. A comprehensive analysis of Helicobacter pylori plasticity zones reveals that they are integrating conjugative elements with intermediate integration specificity. BMC Genomics 2014; 15:310. [PMID: 24767410 PMCID: PMC4234485 DOI: 10.1186/1471-2164-15-310] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 04/16/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The human gastric pathogen Helicobacter pylori is a paradigm for chronic bacterial infections. Its persistence in the stomach mucosa is facilitated by several mechanisms of immune evasion and immune modulation, but also by an unusual genetic variability which might account for the capability to adapt to changing environmental conditions during long-term colonization. This variability is reflected by the fact that almost each infected individual is colonized by a genetically unique strain. Strain-specific genes are dispersed throughout the genome, but clusters of genes organized as genomic islands may also collectively be present or absent. RESULTS We have comparatively analysed such clusters, which are commonly termed plasticity zones, in a high number of H. pylori strains of varying geographical origin. We show that these regions contain fixed gene sets, rather than being true regions of genome plasticity, but two different types and several subtypes with partly diverging gene content can be distinguished. Their genetic diversity is incongruent with variations in the rest of the genome, suggesting that they are subject to horizontal gene transfer within H. pylori populations. We identified 40 distinct integration sites in 45 genome sequences, with a conserved heptanucleotide motif that seems to be the minimal requirement for integration. CONCLUSIONS The significant number of possible integration sites, together with the requirement for a short conserved integration motif and the high level of gene conservation, indicates that these elements are best described as integrating conjugative elements (ICEs) with an intermediate integration site specificity.
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Affiliation(s)
- Wolfgang Fischer
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, D-80336 Munich, Germany.
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Analysis of surface-exposed outer membrane proteins in Helicobacter pylori. J Bacteriol 2014; 196:2455-71. [PMID: 24769695 DOI: 10.1128/jb.01768-14] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
More than 50 Helicobacter pylori genes are predicted to encode outer membrane proteins (OMPs), but there has been relatively little experimental investigation of the H. pylori cell surface proteome. In this study, we used selective biotinylation to label proteins localized to the surface of H. pylori, along with differential detergent extraction procedures to isolate proteins localized to the outer membrane. Proteins that met multiple criteria for surface-exposed outer membrane localization included known adhesins, as well as Cag proteins required for activity of the cag type IV secretion system, putative lipoproteins, and other proteins not previously recognized as cell surface components. We identified sites of nontryptic cleavage consistent with signal sequence cleavage, as well as C-terminal motifs that may be important for protein localization. A subset of surface-exposed proteins were highly susceptible to proteolysis when intact bacteria were treated with proteinase K. Most Hop and Hom OMPs were susceptible to proteolysis, whereas Hor and Hof proteins were relatively resistant. Most of the protease-susceptible OMPs contain a large protease-susceptible extracellular domain exported beyond the outer membrane and a protease-resistant domain at the C terminus with a predicted β-barrel structure. These features suggest that, similar to the secretion of the VacA passenger domain, the N-terminal domains of protease-susceptible OMPs are exported through an autotransporter pathway. Collectively, these results provide new insights into the repertoire of surface-exposed H. pylori proteins that may mediate bacterium-host interactions, as well as the cell surface topology of these proteins.
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Repetto O, Zanussi S, Casarotto M, Canzonieri V, De Paoli P, Cannizzaro R, De Re V. Differential proteomics of Helicobacter pylori associated with autoimmune atrophic gastritis. Mol Med 2014; 20:57-71. [PMID: 24395566 DOI: 10.2119/molmed.2013.00076] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 12/23/2013] [Indexed: 12/20/2022] Open
Abstract
Atrophic autoimmune gastritis (AAG) is a condition of chronic inflammation and atrophy of stomach mucosa, for which development can be partially triggered by the bacterial pathogen Helicobacter pylori (HP). HP can cause a variety of gastric diseases, such as duodenal ulcer (DU) or gastric cancer (GC). In this study, a comparative proteomic approach was used by two-dimensional fluorescence difference gel electrophoresis (DIGE) to identify differentially expressed proteins of HP strains isolated from patients with AAG, to identify markers of HP strain associated with AAG. Proteome profiles of HP isolated from GC or DU were used as a reference to compare proteomic levels. Proteomics analyses revealed 27 differentially expressed spots in AAG-associated HP in comparison with GC, whereas only 9 differential spots were found in AAG-associated HP profiles compared with DU. Proteins were identified after matrix-assisted laser desorption ionization (MALDI)-TOF and peptide mass fingerprinting. Some AAG-HP differential proteins were common between DU- and GC-HP (peroxiredoxin, heat shock protein 70 [HSP70], adenosine 5'-triphosphate [ATP] synthase subunit α, flagellin A). Our results presented here may suggest that comparative proteomes of HP isolated from AAG and DU share more common protein expression than GC and provide subsets of putative AAG-specific upregulated or downregulated proteins that could be proposed as putative markers of AAG-associated HP. Other comparative studies by two-dimensional maps integrated with functional genomics of candidate proteins will undoubtedly contribute to better decipher the biology of AAG-associated HP strains.
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Affiliation(s)
- Ombretta Repetto
- Facility of Bio-Proteomics, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Stefania Zanussi
- Microbiology-Immunology and Virology, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Mariateresa Casarotto
- Microbiology-Immunology and Virology, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Vincenzo Canzonieri
- Pathology Unit, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Paolo De Paoli
- Facility of Bio-Proteomics, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Renato Cannizzaro
- Gastroenterology Unit, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
| | - Valli De Re
- Facility of Bio-Proteomics, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Italy
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Comparative analysis of the full genome of Helicobacter pylori isolate Sahul64 identifies genes of high divergence. J Bacteriol 2013; 196:1073-83. [PMID: 24375107 DOI: 10.1128/jb.01021-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Isolates of Helicobacter pylori can be classified phylogeographically. High genetic diversity and rapid microevolution are a hallmark of H. pylori genomes, a phenomenon that is proposed to play a functional role in persistence and colonization of diverse human populations. To provide further genomic evidence in the lineage of H. pylori and to further characterize diverse strains of this pathogen in different human populations, we report the finished genome sequence of Sahul64, an H. pylori strain isolated from an indigenous Australian. Our analysis identified genes that were highly divergent compared to the 38 publically available genomes, which include genes involved in the biosynthesis and modification of lipopolysaccharide, putative prophage genes, restriction modification components, and hypothetical genes. Furthermore, the virulence-associated vacA locus is a pseudogene and the cag pathogenicity island (cagPAI) is not present. However, the genome does contain a gene cluster associated with pathogenicity, including dupA. Our analysis found that with the addition of Sahul64 to the 38 genomes, the core genome content of H. pylori is reduced by approximately 14% (∼170 genes) and the pan-genome has expanded from 2,070 to 2,238 genes. We have identified three putative horizontally acquired regions, including one that is likely to have been acquired from the closely related Helicobacter cetorum prior to speciation. Our results suggest that Sahul64, with the absence of cagPAI, highly divergent cell envelope proteins, and a predicted nontransportable VacA protein, could be more highly adapted to ancient indigenous Australian people but with lower virulence potential compared to other sequenced and cagPAI-positive H. pylori strains.
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Genomic evolution and transmission of Helicobacter pylori in two South African families. Proc Natl Acad Sci U S A 2013; 110:13880-5. [PMID: 23898187 DOI: 10.1073/pnas.1304681110] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori infects the stomachs of one in two humans and can cause sequelae that include ulcers and cancer. Here we sequenced the genomes of 97 H. pylori isolates from 52 members of two families living in rural conditions in South Africa. From each of 45 individuals, two H. pylori strains were isolated from the antrum and corpus parts of the stomach, and comparisons of their genomes enabled us to study within-host evolution. In 5 of these 45 hosts, the two genomes were too distantly related to be derived from each other and therefore represented evidence of multiple infections. From the remaining 40 genome pairs, we estimated that the synonymous mutation rate was 1.38 × 10(-5) per site per year, with a low effective population size within host probably reflecting population bottlenecks and immune selection. Some individuals showed very little evidence for recombination, whereas in others, recombination introduced up to 100-times more substitutions than mutation. These differences may reflect unequal opportunities for recombination depending on the presence or absence of multiple infections. Comparing the genomes carried by distinct individuals enabled us to establish probable transmission links. Transmission events were found significantly more frequently between close relatives, and between individuals living in the same house. We found, however, that a majority of individuals (27/52) were not linked by transmission to other individuals. Our results suggest that transmission does not always occur within families, and that coinfection with multiple strains is frequent and evolutionarily important despite a fast turnover of the infecting strains within-host.
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Phylogeographic origin of Helicobacter pylori determines host-adaptive responses upon coculture with gastric epithelial cells. Infect Immun 2013; 81:2468-77. [PMID: 23630959 DOI: 10.1128/iai.01182-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
While Helicobacter pylori infects over 50% of the world's population, the mechanisms involved in the development of gastric disease are not fully understood. Bacterial, host, and environmental factors play a role in disease outcome. To investigate the role of bacterial factors in H. pylori pathogenesis, global gene expression of six H. pylori isolates was analyzed during coculture with gastric epithelial cells. Clustering analysis of six Colombian clinical isolates from a region with low gastric cancer risk and a region with high gastric cancer risk segregated strains based on their phylogeographic origin. One hundred forty-six genes had increased expression in European strains, while 350 genes had increased expression in African strains. Differential expression was observed in genes associated with motility, pathogenicity, and other adaptations to the host environment. European strains had greater expression of the virulence factors cagA, vacA, and babB and were associated with increased gastric histologic lesions in patients. In AGS cells, European strains promoted significantly higher interleukin-8 (IL-8) expression than did African strains. African strains significantly induced apoptosis, whereas only one European strain significantly induced apoptosis. Our data suggest that gene expression profiles of clinical isolates can discriminate strains by phylogeographic origin and that these profiles are associated with changes in expression of the proinflammatory and protumorigenic cytokine IL-8 and levels of apoptosis in host epithelial cells. These findings support the hypothesis that bacterial factors determined by the phylogeographic origin of H. pylori strains may promote increased gastric disease.
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