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Sedarat Z, Taylor-Robinson AW. Helicobacter pylori Outer Membrane Proteins and Virulence Factors: Potential Targets for Novel Therapies and Vaccines. Pathogens 2024; 13:392. [PMID: 38787244 PMCID: PMC11124246 DOI: 10.3390/pathogens13050392] [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: 02/26/2024] [Revised: 04/12/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Helicobacter pylori is a gastric oncopathogen that infects over half of the world's human population. It is a Gram-negative, microaerophilic, helix-shaped bacterium that is equipped with flagella, which provide high motility. Colonization of the stomach is asymptomatic in up to 90% of people but is a recognized risk factor for developing various gastric disorders such as gastric ulcers, gastric cancer and gastritis. Invasion of the human stomach occurs via numerous virulence factors such as CagA and VacA. Similarly, outer membrane proteins (OMPs) play an important role in H. pylori pathogenicity as a means to adapt to the epithelial environment and thereby facilitate infection. While some OMPs are porins, others are adhesins. The epithelial cell receptors SabA, BabA, AlpA, OipA, HopQ and HopZ have been extensively researched to evaluate their epidemiology, structure, role and genes. Moreover, numerous studies have been performed to seek to understand the complex relationship between these factors and gastric diseases. Associations exist between different H. pylori virulence factors, the co-expression of which appears to boost the pathogenicity of the bacterium. Improved knowledge of OMPs is a major step towards combatting this global disease. Here, we provide a current overview of different H. pylori OMPs and discuss their pathogenicity, epidemiology and correlation with various gastric diseases.
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Affiliation(s)
- Zahra Sedarat
- Cellular & Molecular Research Centre, Shahrekord University of Medical Sciences, Shahrekord 8813833435, Iran;
| | - Andrew W. Taylor-Robinson
- College of Health Sciences, VinUniversity, Gia Lam District, Hanoi 67000, Vietnam
- Center for Global Health, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 1904, USA
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Helicobacter pylori BabA-SabA Key Roles in the Adherence Phase: The Synergic Mechanism for Successful Colonization and Disease Development. Toxins (Basel) 2021; 13:toxins13070485. [PMID: 34357957 PMCID: PMC8310295 DOI: 10.3390/toxins13070485] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/03/2021] [Accepted: 07/07/2021] [Indexed: 01/21/2023] Open
Abstract
Helicobacter pylori is a pathogenic microorganism that successfully inhabits the human stomach, colonizing it by producing several virulence factors responsible for preventing host self-defense mechanisms. The adherence mechanism to gastric mucosal tissue is one of the most important processes for effective colonization in the stomach. The blood group antigen-binding adhesion (BabA) and sialic acid-binding adherence (SabA) are two H. pylori outer membrane proteins able to interact with antigens in the gastroduodenal tract. H. pylori possesses several mechanisms to control the regulation of both BabA and SabA in either the transcriptional or translational level. BabA is believed to be the most important protein in the early infection phase due to its ability to interact with various Lewis antigens, whereas SabA interaction with sialylated Lewis antigens may prove important for the adherence process in the inflamed gastric mucosal tissue in the ongoing-infection phase. The adherence mechanisms of BabA and SabA allow H. pylori to anchor in the gastric mucosa and begin the colonization process.
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Prevalence of the Helicobacter pylori babA2 Gene in Children Mainly Depends on the PCR Primer Set Used. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2020; 2020:4080248. [PMID: 32855749 PMCID: PMC7443014 DOI: 10.1155/2020/4080248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/20/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023]
Abstract
Various polymerase chain reaction- (PCR-) based methods with varying positivity rates were designed to detect the Helicobacter pylori babA2 gene. To compare different primer sets, babA2 prevalence was determined in 279 H. pylori-positive pediatric samples using the 832 bp, 139 bp, and 271 bp PCR primer sets, resulting in 34.0%, 51.3%, and 79.6% prevalence of the babA2 gene, respectively. The babA2 status determined using the 832 bp and 139 bp PCR primer sets significantly correlated with bacterial density and activity of inflammation, whereas no such correlations were found using the 271 bp PCR primer set. The 139 and 832 bp PCR primer sets concordantly detected the babA2 gene in 93 cases; however, in comparison to the 832 bp PCR primer set, the 139 bp PCR primer set detected additional 50 babA2 cases, whereas only two 832 bp positive cases were missed. The 271 bp PCR primer set missed 32 babA2 cases that were 832 bp and/or 139 bp PCR positive, but tested solely positive in 109 cases. Interestingly, cloning of a subset of 271 bp PCR positive samples revealed amplification of the babA/B gene chimera. Hence, in our opinion, the 271 bp PCR protocol is not a reliable diagnostic tool for detecting the babA2 gene in children. Our results reaffirm previous observations that the use of certain babA2 PCR primer sets can significantly impact estimation of the prevalence and clinical relevance of the H. pylori babA2 gene in children, suggesting babA2 detection methods should be carefully selected.
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Hanafiah A, Lopes BS. Genetic diversity and virulence characteristics of Helicobacter pylori isolates in different human ethnic groups. INFECTION GENETICS AND EVOLUTION 2019; 78:104135. [PMID: 31837482 DOI: 10.1016/j.meegid.2019.104135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 12/03/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori is the most predominant bacterium in almost 50% of the world's population and colonization causes a persistent inflammatory response leading to chronic gastritis. It shows high genetic diversity and individuals generally harbour a distinct bacterial population. With the advancement of whole-genome sequencing technology, new H. pylori subpopulations have been identified that show admixture between various H. pylori strains. Genotypic variation of H. pylori may be related to the presence of virulence factors among strains and is associated with different outcomes of infection in different individuals. This review summarizes the genetic diversity in H. pylori strain populations and its virulence characteristics responsible for variable outcomes in different ethnic groups.
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Affiliation(s)
- Alfizah Hanafiah
- Department of Medical Microbiology & Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000 Cheras, Kuala Lumpur, Malaysia.
| | - Bruno S Lopes
- Department of Medical Microbiology, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, 0:025 Polwarth Building, Aberdeen AB25 2ZD, United Kingdom.
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Isaeva GS. Pangenomic studies of Helicobacter pylori: a key to understanding pathogenesis and human history. MINERVA BIOTECNOL 2019. [DOI: 10.23736/s1120-4826.19.02564-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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6
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Zhao H, Xu L, Xu Z, Ding Y, Yu H, Zhang Y, Wu Y, Li B, Ji X. Investigation on the role of gene hp0788 in Helicobacter pylori in infecting gastric epithelial cells. Microb Pathog 2019; 137:103739. [PMID: 31513896 DOI: 10.1016/j.micpath.2019.103739] [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: 04/09/2019] [Revised: 08/20/2019] [Accepted: 09/08/2019] [Indexed: 11/30/2022]
Abstract
Helicobacter pylori infection can cause a wide range of digestive diseases. Gene hp0788 encodes an outer membrane protein HofF, which can reduce the bacterial adherence to the GES-1 cells and affect pathogenesis of H. pylori. In this study, the role of hp0788 in H. pylori infection was further analyzed. RNA-seq data showed that two genes (hp0523 and hp0539), located on the cagPAI, were down-regulated in Δ0788 mutant. The changes were confirmed through qRT-PCR, and the expression of these two genes will be almost recovered to the normal level in complemented strain. These two genes, hp0523 and hp0539, are known to be necessary for integrated T4SS, which related to CagA translocation and IL-8 induction. In H. pylori infected assay, lower amount of phosphorylated CagA and lower induction of IL-8 were both detected in GES-1 cells infected by Δ0788 mutant, compared with the wild type strain. Meanwhile, these reductions almost recovered to the wild-type level in complemented strain. These results reveal that there is a correlation between hp0788 disruption and CagA/IL-8 decline. Deletion of CagA-encoding gene (hp0547) in Δ0788 mutant was further constructed. The double deleted mutant shows lower IL-8-inducing capability than Δ0788 mutant, indicated the correlation between deficiency of CagA and reduced IL-8 production. These results together imply that disruption of hp0788 might affect the efficiency of T4SS and CagA injection, then weaken the induction of IL-8 in infected GES-1 cells.
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Affiliation(s)
- Huilin Zhao
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Linlin Xu
- Department of Neurology, Second Hospital, Shandong University, Jinan, China
| | - Zheng Xu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Yunfei Ding
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Haonan Yu
- School of Clinical Medicine, Binzhou Medical University, Yantai, China
| | - Ying Zhang
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Yulong Wu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China
| | - Boqing Li
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China.
| | - Xiaofei Ji
- Department of Pathogenic Biology, School of Basic Medical Sciences, Binzhou Medical University, Yantai, China.
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Gupta N, Maurya S, Verma H, Verma VK. Unraveling the factors and mechanism involved in persistence: Host-pathogen interactions in Helicobacter pylori. J Cell Biochem 2019; 120:18572-18587. [PMID: 31237031 DOI: 10.1002/jcb.29201] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 05/20/2019] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori and humans have one of the most complex relationships in nature. How a bacterium manages to live in one of the harshest and hostile environments is a topic of unraveling mysteries. H. pylori is a prevalent species and it colonizes the human gut of more than 50% of the world population. It infects the epithelial region of antrum and persists there for a long period. Over the time of evolution, H. pylori has developed complex strategies to extend the degree of inflammation in gastric mucosa. H. pylori needs specific adaptations for initial colonization into the host environment like helical shape, flagellar movement, chemotaxis, and the production of urease enzyme that neutralizes acidic environment of the stomach. There are several factors from the bacterium as well as from the host that participate in these complex interactions. On the other hand, to establish the persistent infection, H. pylori escapes the immune system by mimicking the host antigens. This pathogen has the ability to dodge the immune system and then persist there in the form of host cell, which leads to immune tolerance. H. pylori has an ability to manipulate its own pathogen-associated molecular patterns, which leads to an inhibition in the binding with specific pattern recognition receptors of the host to avoid immune cell detection. Also, it manipulates the host metabolic homeostasis in the gastric epithelium. Besides, it has several genes, which may get involved in the acquisition of nutrition from the host to survive longer in the host. Due to the persistence of H. pylori, it causes chronic inflammation and raises the chances of gastric cancer. This review highlights the important elements, which are certainly responsible for the persistence of H. pylori in the human host.
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Affiliation(s)
- Nidhi Gupta
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Kishangarh, India
| | - Shweta Maurya
- Department of Microbiology, School of Life Sciences, Central University of Rajasthan, Kishangarh, India
| | - Harshvardhan Verma
- Department of Microbiology, School of Life Sciences, Central University of Rajasthan, Kishangarh, India
| | - Vijay K Verma
- Department of Microbiology, School of Life Sciences, Central University of Rajasthan, Kishangarh, India
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Javed S, Skoog EC, Solnick JV. Impact of Helicobacter pylori Virulence Factors on the Host Immune Response and Gastric Pathology. Curr Top Microbiol Immunol 2019; 421:21-52. [PMID: 31123884 DOI: 10.1007/978-3-030-15138-6_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Helicobacter pylori chronically infects nearly half the world's population, yet most of those infected remain asymptomatic throughout their lifetime. The outcome of infection-peptic ulcer disease or gastric cancer versus asymptomatic colonization-is a product of host genetics, environmental influences, and differences in bacterial virulence factors. Here, we review the current understanding of the cag pathogenicity island (cagPAI), the vacuolating cytotoxin (VacA), and a large family of outer membrane proteins (OMPs), which are among the best understood H. pylori virulence determinants that contribute to disease. Each of these virulence factors is characterized by allelic and phenotypic diversity that is apparent within and across individuals, as well as over time, and modulates inflammation. From the bacterial perspective, inflammation is probably a necessary evil because it promotes nutrient acquisition, but at the cost of reduction in bacterial load and therefore decreases the chance of transmission to a new host. The general picture that emerges is one of a chronic bacterial infection that is dependent on both inducing and carefully regulating the host inflammatory response. A better understanding of these regulatory mechanisms may have implications for the control of chronic inflammatory diseases that are increasingly common causes of human morbidity and mortality.
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Affiliation(s)
- Sundus Javed
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA.,Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Emma C Skoog
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA
| | - Jay V Solnick
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA. .,Center for Comparative Medicine, University of California, Davis, Davis, CA, 95616, USA.
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9
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Bonsor DA, Sundberg EJ. Roles of Adhesion to Epithelial Cells in Gastric Colonization by Helicobacter pylori. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:57-75. [PMID: 31016628 DOI: 10.1007/5584_2019_359] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Helicobacter pylori adherence to host epithelial cells is essential for its survival against the harsh conditions of the stomach and for successful colonization. Adherence of H. pylori is achieved through several related families of outer membrane proteins and proteins of a type IV secretion system (T4SS), which bridge H. pylori to host cells through protein-protein and other protein-ligand interactions. Local environmental conditions such as cell type, available host cell surface proteins and/or ligands, as well as responses by the host immune system force H. pylori to alter expression of these proteins to adapt quickly to the local environment in order to colonize and survive. Some of these host-pathogen interactions appear to function in a "catch-and-release" manner, regulated by reversible binding at varying pH and allowing H. pylori to detach itself from cells or debris sloughed off the gastric epithelial lining in order to return for subsequent productive interactions. Other interactions between bacterial adhesin proteins and host adhesion molecules, however, appear to function as a committed step in certain pathogenic processes, such as translocation of the CagA oncoprotein through the H. pylori T4SS and into host gastric epithelial cells. Understanding these adhesion interactions is critical for devising new therapeutic strategies, as they are responsible for the earliest stage of infection and its maintenance. This review will discuss the expression and regulation of several outer membrane proteins and CagL, how they engage their known host cell protein/ligand targets, and their effects on clinical outcome.
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Affiliation(s)
- Daniel A Bonsor
- Institute of Human Virology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Eric J Sundberg
- Institute of Human Virology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD, USA. .,Department of Medicine, University of Maryland School of Medicine, University of Maryland, Baltimore, MD, USA. .,Department of Microbiology and Immunology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD, USA.
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10
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Whitmire JM, Merrell DS. Helicobacter pylori Genetic Polymorphisms in Gastric Disease Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:173-194. [DOI: 10.1007/5584_2019_365] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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11
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Noto JM, Chopra A, Loh JT, Romero-Gallo J, Piazuelo MB, Watson M, Leary S, Beckett AC, Wilson KT, Cover TL, Mallal S, Israel DA, Peek RM. Pan-genomic analyses identify key Helicobacter pylori pathogenic loci modified by carcinogenic host microenvironments. Gut 2018; 67:1793-1804. [PMID: 28924022 PMCID: PMC5857411 DOI: 10.1136/gutjnl-2017-313863] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/30/2017] [Accepted: 07/15/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Helicobacter pylori is the strongest risk factor for gastric cancer; however, the majority of infected individuals do not develop disease. Pathological outcomes are mediated by complex interactions among bacterial, host and environmental constituents, and two dietary factors linked with gastric cancer risk are iron deficiency and high salt. We hypothesised that prolonged adaptation of H. pylori to in vivo carcinogenic microenvironments results in genetic modification important for disease. DESIGN Whole genome sequencing of genetically related H. pylori strains that differ in virulence and targeted H. pylori sequencing following prolonged exposure of bacteria to in vitro carcinogenic conditions were performed. RESULTS A total of 180 unique single nucleotide polymorphisms (SNPs) were identified among the collective genomes when compared with a reference H. pylori genome. Importantly, common SNPs were identified in isolates harvested from iron-depleted and high salt carcinogenic microenvironments, including an SNP within fur (FurR88H). To investigate the direct role of low iron and/or high salt, H. pylori was continuously cultured in vitro under low iron or high salt conditions to assess fur genetic variation. Exposure to low iron or high salt selected for the FurR88H variant after only 5 days. To extend these results, fur was sequenced in 339 clinical H. pylori strains. Among the isolates examined, 17% (40/232) of strains isolated from patients with premalignant lesions harboured the FurR88H variant, compared with only 6% (6/107) of strains from patients with non-atrophic gastritis alone (p=0.0034). CONCLUSION These results indicate that specific genetic variation arises within H. pylori strains during in vivo adaptation to conditions conducive for gastric carcinogenesis.
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Affiliation(s)
- Jennifer M Noto
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia
| | - John T Loh
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Judith Romero-Gallo
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Blanca Piazuelo
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark Watson
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia
| | - Shay Leary
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia
| | - Amber C Beckett
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Keith T Wilson
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA,Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Timothy L Cover
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA,Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, Tennessee, USA
| | - Simon Mallal
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia,Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, Tennessee, USA
| | - Dawn A Israel
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Richard M Peek
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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12
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Coppens F, Castaldo G, Debraekeleer A, Subedi S, Moonens K, Lo A, Remaut H. Hop‐familyHelicobacterouter membrane adhesins form a novel class of Type 5‐like secretion proteins with an interrupted β‐barrel domain. Mol Microbiol 2018; 110:33-46. [DOI: 10.1111/mmi.14075] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2018] [Indexed: 01/10/2023]
Affiliation(s)
- Fanny Coppens
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Gaetano Castaldo
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Ayla Debraekeleer
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Suresh Subedi
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Kristof Moonens
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Alvin Lo
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
| | - Han Remaut
- Structural and Molecular Microbiology VIB‐VUB Center for Structural Biology, VIB Brussels Belgium
- Structural Biology Brussels Vrije Universiteit Brussel Brussels Belgium
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13
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Isaeva G, Valieva R. Biological characteristics and virulence of Helicobacter pylori. CLINICAL MICROBIOLOGY AND ANTIMICROBIAL CHEMOTHERAPY 2018. [DOI: 10.36488/cmac.2018.1.14-23] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
This review summarizes the most recent data on the biological characteristics of Helicobacter pylori (morphological, cultural, biochemical). H. pylori pathogenicity factors promoting colonization, adhesion, biofilm formation, aggression, and cytotoxicity, their contribution to the pathogenesis of diseases as well as the possible relationships with various clinical outcomes are described in detail. The genetic heterogeneity of H. pylori strains which can determine different clinical manifestations and have significance for conducting epidemiological studies is also considered.
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Affiliation(s)
- G.Sh. Isaeva
- Kazan Research Institute of Epidemiology and Microbiology; Kazan State Medical University (Kazan, Russia)
| | - R.I. Valieva
- Kazan Research Institute of Epidemiology and Microbiology; KazanState Medical University (Kazan, Russia)
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14
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Ansari S, Kabamba ET, Shrestha PK, Aftab H, Myint T, Tshering L, Sharma RP, Ni N, Aye TT, Subsomwong P, Uchida T, Ratanachu-ek T, Vilaichone RK, Mahachai V, Matsumoto T, Akada J, Yamaoka Y. Helicobacter pylori bab characterization in clinical isolates from Bhutan, Myanmar, Nepal and Bangladesh. PLoS One 2017; 12:e0187225. [PMID: 29107979 PMCID: PMC5673166 DOI: 10.1371/journal.pone.0187225] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 10/16/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Helicobacter pylori BabA is an important outer membrane protein that involves in the attachment to the gastric mucosa and enhances the virulence property of the bacterium. This study was aimed to characterize the bab genotypes, to evaluate its association with cagA, vacA and clinical diseases as well as degree of gastric inflammation. METHODS H. pylori isolates from four countries were subjected for the characterization of bab. The locus specific forward and bab specific reverse primers were used to get the specific products by PCR, which could distinguish the three locus (A, B and C). The histological activities were evaluated according to the Updated Sydney system. RESULT In patients from high risk countries (Bhutan and Myanmar) relatively higher frequencies of strains with babA-positivity (91.8% and 90.7%, respectively), babA at locus A (98% and 91.2%, respectively) and with single babA (96.8% and 91.2%, respectively) were found. Strains with two loci occupied were the most prevalent in Bhutan (84.6%), Myanmar (74.7%), Nepal (58.3%) and Bangladesh (56.9%). The genotype babA at locus A/babB at locus B/bab-negative at locus C (babA/babB/-) was the most common genotype isolated from Bhutan (82.7%), Myanmar (58.7%), Nepal (32%) and Bangladesh (31.4%) among all genotypes assessed. This genotype was also associated with the peptic ulcer disease (P = 0.013) when compared to gastritis. babA-positive characteristics and the genotype babA/babB/- exhibited the enhanced histological activities. CONCLUSIONS The higher prevalence of virulence associated babA-positive characteristics and enhanced histological activities in Bhutan than in Myanmar, Nepal and Bangladesh might partly explain why the peoples in Bhutan are at higher risk for developing severe gastric complications.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | | | - Pradeep Krishna Shrestha
- Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Hafeza Aftab
- Department of Gastroenterology, Dhaka Medical College and Hospital, Dhaka, Bangladesh
| | - Thein Myint
- Department of Gastroenterology, Yangon General Hospital, Yangon, Myanmar
| | - Lotay Tshering
- Department of Surgery, Jigme Dorji Wangchuck National Referral Hospital, Thimphu, Bhutan
| | - Rabi Prakash Sharma
- Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Nwe Ni
- Department of Gastroenterology, Mandalay General Hospital and University of Medicine (Mandalay), Mandalay, Myanmar
| | - Than Than Aye
- Department of Gastroenterology, Thingangyun Sanpya General Hospital and University of Medicine (2), Thingangyun, Myanmar
| | - Phawinee Subsomwong
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Tomohisa Uchida
- Department of Molecular Pathology, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan
| | | | - Ratha-korn Vilaichone
- Gastroenterology Unit, Department of Medicine, Thammasat University Hospital, Pathum Thani, Thailand
| | | | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Junko Akada
- 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, TX, United States of America
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15
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Sohrabi M, Khashei R, Alizadeh M, Asl MKH, Nejati MA, Dara M, Bazargani A. Low Rate of babA2 Genotype among Iranian Helicobacter pylori Clinical Isolates. J Clin Diagn Res 2017; 11:DC32-DC36. [PMID: 28892894 DOI: 10.7860/jcdr/2017/24810.10277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 05/04/2017] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The Blood Group Antigen-Binding Adhesion (babA), Outer Inflammatory Protein (oipA) and Sialic Acid-Binding Adhesin (sabA) as outer membrane proteins involved in Helicobacter pylori adherence to gastric mucosa have been suggested to have a role in the pathogenesis. AIM To investigate the frequency of H. pylori isolates babA2, oipA and sabA genes in Iranian dyspeptic patients. MATERIALS AND METHODS DNAs were extracted from H. pylori -positive cultures taken from 100 different dyspeptic patients. Genotyping was performed by Polymerase Chain Reaction (PCR), using the specific primers for babA2, oipA and sabA genes. Chi square test was used to investigate association between variables, p<0.05 was considered statistically significant. RESULTS All (100%) isolates possessed oipA and sabA genotypes, whereas babA2 was detected in 22% of isolates. There was no significant relationship between presence of genes with clinical outcome. The combined genotype oipA +/sabA +/ babA2- was correlated with gastritis. The rate of babA2 genotype in our isolates was lower than other Iranian reports. CONCLUSION Frequency of babA2 genotype among H. pylori isolates from Southwest of Iran is considerably less than other regions of Iran. Due to heterogeneity of H. pylori strains in different geographic regions, further work will be needed to understand the role of these virulence genes in H. pylori pathogenesis and their possible association with disease outcome.
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Affiliation(s)
- Maryam Sohrabi
- Student, Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Reza Khashei
- Assistant Professor, Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahvash Alizadeh
- Assistant Professor, Department of Internal Medicine, Gastroenterology Ward, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad-Kazem Hosseini Asl
- Associate Professor, Department of Internal Medicine, Gastroenterology Ward, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad-Ali Nejati
- Assistant Professor, Department of Internal Medicine, Gastroenterology Ward, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahintaj Dara
- Ph.D Student, Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abdollah Bazargani
- Associate Professor, Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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16
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Ansari S, Yamaoka Y. Helicobacter pylori BabA in adaptation for gastric colonization. World J Gastroenterol 2017; 23:4158-4169. [PMID: 28694656 PMCID: PMC5483490 DOI: 10.3748/wjg.v23.i23.4158] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 04/12/2017] [Accepted: 06/01/2017] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) as a causative agent of gastric complications, is well adapted for the colonization of gastric mucosa. Although the infectious process depends on several factors, the adhesion to the gastric mucosa is the first and important step. Among several outer membrane proteins, BabA is one of the significant protein involving in many inflammatory processes in addition to its role in the attachment for the persistent colonization. We performed a PubMed search using the key words: “babA”, “pylori”, “gastric complications”, “homologous recombination”, “slipped strand mispairing”; a total of 249 articles were displayed. Of these we mainly focused on articles with the full text in English and published between 2005 and 2016. H. pylori BabA is involved in binding with receptors; however, its synthesis is regulated by phase variation. In this review we confirm that H. pylori babA can be modulated at the molecular and functional levels to adapt to the stress within the gastro-intestinal tract.
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Acio-Pizzarello CR, Acio AA, Choi EJ, Bond K, Kim J, Kenan AC, Chen J, Forsyth MH. Determinants of the regulation of Helicobacter pylori adhesins include repeat sequences in both promoter and coding regions as well as the two-component system ArsRS. J Med Microbiol 2017; 66:798-807. [PMID: 28598306 DOI: 10.1099/jmm.0.000491] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PURPOSE We investigated the transcription of adhesin-encoding genes sabA, hopZ and labA in Helicobacter pylori strain J99. Each possesses a repeating homopolymeric nucleotide tract within their promoter regions, and sabA and hopZ possess repeats within their 5' coding regions. METHODOLOGY We altered the repeat lengths associated with the adhesin genes and quantified mRNA levels by real-time quantitative PCR. Using adherence to AGS cells and IL-8 assays, we examined the effects of altered transcript levels. We assessed the role of ArsRS in transcription using an arsS null mutant and by examining ArsR binding to promoter regions via electrophoretic mobility shift assays. RESULTS Extensions or truncations of promoter region repeats in hopZ and labA increased transcript levels, mirroring results shown by our lab and others for mutations in the sabA promoter. Altered lengths of the poly-cytosine thymine tract within the 5' coding region of sabA demonstrated that switching from phase-off to phase-on significantly increased mRNA levels. However, mutations in the poly-thymine tract of sabA, which increased mRNA levels, do not behave synergistically with phase-on mutations. Phase-on mutations of sabA resulted in increased H. pylori adherence to AGS cells, but only a modest effect on IL-8. hopZ and labA, and sabA paralogue sabB, transcript levels were increased in an arsS mutant and ArsR bound the promoter regions for each of these genes in vitro. CONCLUSION This work highlights the complex nature of adhesin regulation, its impact on H. pylori attachment and the pervasive role of ArsRS in adhesin expression. Such regulation may help facilitate the decades-long persistence of infection.
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Affiliation(s)
- Catherine R Acio-Pizzarello
- Department of Biology, College of William and Mary, Williamsburg, VA, USA.,Present address: University of Rochester School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - Abigail A Acio
- Department of Biology, College of William and Mary, Williamsburg, VA, USA.,Present address: Department of Forensic Science, Pennsylvania State University, State College, PA, USA
| | - Edward J Choi
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - Kimberly Bond
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - June Kim
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - Anna C Kenan
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - Jiajia Chen
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
| | - Mark H Forsyth
- Department of Biology, College of William and Mary, Williamsburg, VA, USA
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18
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Dynamic Expression of the BabA Adhesin and Its BabB Paralog during Helicobacter pylori Infection in Rhesus Macaques. Infect Immun 2017; 85:IAI.00094-17. [PMID: 28396320 DOI: 10.1128/iai.00094-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/02/2017] [Indexed: 02/07/2023] Open
Abstract
Most Helicobacter pylori strains express the BabA adhesin, which binds to ABO/Leb blood group antigens on gastric mucin and epithelial cells and is found more commonly in strains that cause peptic ulcers or gastric cancer, rather than asymptomatic infection. We and others have previously reported that in mice, gerbils, and rhesus macaques, expression of babA is lost, either by phase variation or by gene conversion, in which the babB paralog recombines into the babA locus. The functional significance of loss of babA expression is unknown. Here we report that in rhesus monkeys, there is independent selective pressure for loss of babA and for overexpression of BabB, which confers a fitness advantage. Surprisingly, loss of babA by phase variation or gene conversion is not dependent on the capacity of BabA protein to bind Leb, which suggests that it may have other, unrecognized functions. These findings have implications for the role of outer membrane protein diversity in persistent H. pylori infection.
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19
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Chua EG, Wise MJ, Khosravi Y, Seow SW, Amoyo AA, Pettersson S, Peters F, Tay CY, Perkins TT, Loke MF, Marshall BJ, Vadivelu J. Quantum changes in Helicobacter pylori gene expression accompany host-adaptation. DNA Res 2017; 24:37-49. [PMID: 27803027 PMCID: PMC5381349 DOI: 10.1093/dnares/dsw046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/23/2016] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a highly successful gastric pathogen. High genomic plasticity allows its adaptation to changing host environments. Complete genomes of H. pylori clinical isolate UM032 and its mice-adapted serial derivatives 298 and 299, generated using both PacBio RS and Illumina MiSeq sequencing technologies, were compared to identify novel elements responsible for host-adaptation. The acquisition of a jhp0562-like allele, which encodes for a galactosyltransferase, was identified in the mice-adapted strains. Our analysis implies a new β-1,4-galactosyltransferase role for this enzyme, essential for Ley antigen expression. Intragenomic recombination between babA and babB genes was also observed. Further, we expanded on the list of candidate genes whose expression patterns have been mediated by upstream homopolymer-length alterations to facilitate host adaption. Importantly, greater than four-fold reduction of mRNA levels was demonstrated in five genes. Among the down-regulated genes, three encode for outer membrane proteins, including BabA, BabB and HopD. As expected, a substantial reduction in BabA protein abundance was detected in mice-adapted strains 298 and 299 via Western analysis. Our results suggest that the expression of Ley antigen and reduced outer membrane protein expressions may facilitate H. pylori colonisation of mouse gastric epithelium.
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Affiliation(s)
- Eng-Guan Chua
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Michael J Wise
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia.,School of Computer Science and Software Engineering, The University of Western Australia, Australia
| | - Yalda Khosravi
- Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Sven Pettersson
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.,LKC School of Medicine, Nanyang Technological University, Singapore.,SCELSE Microbiome Centre, Nanyang Technological University, Singapore
| | - Fanny Peters
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Chin-Yen Tay
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Timothy T Perkins
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Mun-Fai Loke
- Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia
| | - Barry J Marshall
- The Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia.,UM Marshall Centre, High Impact Research Building, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Jamuna Vadivelu
- Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia
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20
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Host Determinants of Expression of the Helicobacter pylori BabA Adhesin. Sci Rep 2017; 7:46499. [PMID: 28418004 PMCID: PMC5394467 DOI: 10.1038/srep46499] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/17/2017] [Indexed: 12/19/2022] Open
Abstract
Expression of the Helicobacter pylori blood group antigen binding adhesin A (BabA) is more common in strains isolated from patients with peptic ulcer disease or gastric cancer, rather than asymptomatic colonization. Here we used mouse models to examine host determinants that affect H. pylori BabA expression. BabA expression was lost by phase variation as frequently in WT mice as in RAG2−/− mice that do not have functional B or T cells, and in MyD88−/−, TLR2−/− and TLR4−/− mice that are defective in toll like receptor signaling. The presence of other bacteria had no effect on BabA expression as shown by infection of germ free mice. Moreover, loss of BabA expression was not dependent on Leb expression or the capacity of BabA to bind Leb. Surprisingly, gender was the host determinant most associated with loss of BabA expression, which was maintained to a greater extent in male mice and was associated with greater bacterial load. These results suggest the possibility that loss of BabA expression is not driven by adaptive immunity or toll-like receptor signaling, and that BabA may have other, unrecognized functions in addition to serving as an adhesin that binds Leb.
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21
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Saberi S, Schmidt A, Eybpoosh S, Esmaili M, Talebkhan Y, Mohajerani N, Oghalaie A, Eshagh Hosseini M, Mohagheghi MA, Bugaytova J, Borén T, Mohammadi M. Helicobacter pylori Strains from Duodenal Ulcer Patients Exhibit Mixed babA/B Genotypes with Low Levels of BabA Adhesin and Lewis b Binding. Dig Dis Sci 2016; 61:2868-2877. [PMID: 27318698 DOI: 10.1007/s10620-016-4217-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/27/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND BabA is a Helicobacter pylori cell surface adhesin, which binds to the ABO/Le(b) histo-blood group antigens (Le(b)) and serves as a virulence factor. METHODS H. pylori single colonies were isolated from 156 [non-ulcer dyspepsia (NUD) = 97, duodenal ulcer (DU) = 34, gastric cancer (GC) = 25)] patients. babA and babB genes were evaluated by gene/locus-specific PCR. BabA protein expression and Le(b) binding activity were determined by immunoblotting and ELISA, respectively. RESULTS The combined categorization of H. pylori strains based on high, low or no levels of BabA expression and Le(b) binding, produced 4 groups: (I) BabA-high/Le(b)-high (36 %), (II) BabA-low/Le(b)-low (26 %), (III) BabA-neg/Le(b)-low (30 %) and (IV) BabA-neg/Le(b)-neg (8 %) strains. The majority (63 %) of the BabA-low/Le(b)-low strains exhibited mixed babA/B genotypes as compared to merely 18 % of the BabA-high/Le(b)-high, 15 % of the BabA-neg/Le(b)-neg and 11 % of the BabA-neg/Le(b)-low (P = 0.0001) strains. In contrast to NUD strains, the great majority (70 %) of DU strains were BabA-low/Le(b)-low (11 %, P = 0.0001), which compared to NUD strains, enhanced the risk of DU by 18.8-fold. In parallel, infection with babA/B mixed genotype strains amplified the risk of DU by 3.6-fold (vs. babA-positive: P = 0.01) to 6.9-fold (vs. babA-negative: P = 0.007). CONCLUSIONS Here, we show higher prevalence of mixed babA/B genotypes among BabA-low/Le(b)-low clinical strains. Recombination of babA and babB genes across their loci may yield lower BabA expression and lower Le(b) binding activity. We conclude that H. pylori strains with lower Le(b) binding activity are better adapted for colonization of the gastric metaplastic patches in the duodenum and enhance the risk of duodenal ulcers.
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Affiliation(s)
- Samaneh Saberi
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Alexej Schmidt
- Department of Medical Biosciences and Pathology, Umeå University, 901 85, Umeå, Sweden
| | - Sana Eybpoosh
- Research Center for Modeling in Health, Institute for Future Studies in Health, Kerman University of Medical Sciences, Kerman, 7618747653, Iran
| | - Maryam Esmaili
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Yeganeh Talebkhan
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Nazanin Mohajerani
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Akbar Oghalaie
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran
| | - Mahmoud Eshagh Hosseini
- Department of Gastroenterology, Amiralam Hospital, Tehran University of Medical Sciences, Tehran, 1145765111, Iran
| | | | - Jeanna Bugaytova
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87, Umeå, Sweden
| | - Thomas Borén
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87, Umeå, Sweden.
| | - Marjan Mohammadi
- HPGC Group, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
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Ji X, Zhao H, Zhang Y, Chen X, Li J, Li B. Construction of Novel Plasmid Vectors for Gene Knockout in Helicobacter pylori. Curr Microbiol 2016; 73:897-903. [DOI: 10.1007/s00284-016-1140-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/13/2016] [Indexed: 02/07/2023]
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23
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Kim A, Servetas SL, Kang J, Kim J, Jang S, Cha HJ, Lee WJ, Kim J, Romero-Gallo J, Peek RM, Merrell DS, Cha JH. Helicobacter pylori bab Paralog Distribution and Association with cagA, vacA, and homA/B Genotypes in American and South Korean Clinical Isolates. PLoS One 2015; 10:e0137078. [PMID: 26317221 PMCID: PMC4552749 DOI: 10.1371/journal.pone.0137078] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 08/13/2015] [Indexed: 12/19/2022] Open
Abstract
Helicobacter pylori genetic variation is a crucial component of colonization and persistence within the inhospitable niche of the gastric mucosa. As such, numerous H. pylori genes have been shown to vary in terms of presence and genomic location within this pathogen. Among the variable factors, the Bab family of outer membrane proteins (OMPs) has been shown to differ within subsets of strains. To better understand genetic variation among the bab genes and to determine whether this variation differed among isolates obtained from different geographic locations, we characterized the distribution of the Bab family members in 80 American H. pylori clinical isolates (AH) and 80 South Korean H. pylori clinical isolates (KH). Overall, we identified 23 different bab genotypes (19 in AH and 11 in KH), but only 5 occurred in greater than 5 isolates. Regardless of strain origin, a strain in which locus A and locus B were both occupied by a bab gene was the most common (85%); locus C was only occupied in those isolates that carried bab paralog at locus A and B. While the babA/babB/- genotype predominated in the KH (78.8%), no single genotype could account for greater than 40% in the AH collection. In addition to basic genotyping, we also identified associations between bab genotype and well known virulence factors cagA and vacA. Specifically, significant associations between babA at locus A and the cagA EPIYA-ABD motif (P<0.0001) and the vacA s1/i1/m1 allele (P<0.0001) were identified. Log-linear modeling further revealed a three-way association between bab carried at locus A, vacA, and number of OMPs from the HOM family (P<0.002). En masse this study provides a detailed characterization of the bab genotypes from two distinct populations. Our analysis suggests greater variability in the AH, perhaps due to adaptation to a more diverse host population. Furthermore, when considering the presence or absence of both the bab and homA/B paralogs at their given loci and the vacA genotype, an association was observed. Our results highlight the multifactorial nature of H. pylori mediated disease and the importance of considering how the specific combinations of H. pylori virulence genes and their multiple interactions with the host will collectively impact disease progression.
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Affiliation(s)
- Aeryun Kim
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
- Department of Applied Life Science, BK21 Plus Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Stephanie L. Servetas
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, Maryland, 20814, United States of America
| | - Jieun Kang
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
- Department of Applied Life Science, BK21 Plus Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Jinmoon Kim
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
- Department of Applied Life Science, BK21 Plus Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Sungil Jang
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
| | - Ho Jin Cha
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
| | - Wan Jin Lee
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
| | - June Kim
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
| | - Judith Romero-Gallo
- Departments of Cancer Biology and Medicine, Vanderbilt University, Nashville, Tennessee, 37240, United States of America
| | - Richard M. Peek
- Departments of Cancer Biology and Medicine, Vanderbilt University, Nashville, Tennessee, 37240, United States of America
| | - D. Scott Merrell
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, Maryland, 20814, United States of America
- * E-mail: (DSM); (JHC)
| | - Jeong-Heon Cha
- Department of Oral Biology, Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
- Department of Applied Life Science, BK21 Plus Project, Yonsei University College of Dentistry, Seoul, South Korea
- * E-mail: (DSM); (JHC)
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Analysis of a single Helicobacter pylori strain over a 10-year period in a primate model. Int J Med Microbiol 2015; 305:392-403. [PMID: 25804332 DOI: 10.1016/j.ijmm.2015.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/30/2015] [Accepted: 03/01/2015] [Indexed: 12/18/2022] Open
Abstract
Helicobacter pylori from different individuals exhibits substantial genetic diversity. However, the kinetics of bacterial diversification after infection with a single strain is poorly understood. We investigated evolution of H. pylori following long-term infection in the primate stomach; Rhesus macaques were infected with H. pylori strain USU101 and then followed for 10 years. H. pylori was regularly cultured from biopsies, and single colony isolates were analyzed. At 1-year, DNA fingerprinting showed that all output isolates were identical to the input strain; however, at 5-years, different H. pylori fingerprints were observed. Microarray-based comparative genomic hybridization revealed that long term persistence of USU101 in the macaque stomach was associated with specific whole gene changes. Further detailed investigation showed that levels of the BabA protein were dramatically reduced within weeks of infection. The molecular mechanisms behind this reduction were shown to include phase variation and gene loss via intragenomic rearrangement, suggesting strong selective pressure against BabA expression in the macaque model. Notably, although there is apparently strong selective pressure against babA, babA is required for establishment of infection in this model as a strain in which babA was deleted was unable to colonize experimentally infected macaques.
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25
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Dynamics of Lewis b binding and sequence variation of the babA adhesin gene during chronic Helicobacter pylori infection in humans. mBio 2014; 5:mBio.02281-14. [PMID: 25516619 PMCID: PMC4271554 DOI: 10.1128/mbio.02281-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori undergoes rapid microevolution during chronic infection, but very little is known about how this affects host interaction factors. The best-studied adhesin of H. pylori is BabA, which mediates binding to the blood group antigen Lewis b [Le(b)]. To study the dynamics of Le(b) adherence during human infection, we analyzed paired H. pylori isolates obtained sequentially from chronically infected individuals. A complete loss or significant reduction of Le(b) binding was observed in strains from 5 out of 23 individuals, indicating that the Le(b) binding phenotype is quite stable during chronic human infection. Sequence comparisons of babA identified differences due to mutation and/or recombination in 12 out of 16 strain pairs analyzed. Most amino acid changes were found in the putative N-terminal extracellular adhesion domain. One strain pair that had changed from a Le(b) binding to a nonbinding phenotype was used to study the role of distinct sequence changes in Le(b) binding. By transformations of the nonbinding strain with a babA gene amplified from the binding strain, H. pylori strains with mosaic babA genes were generated. Recombinants were enriched for a gain of Le(b) binding by biopanning or for BabA expression on the bacterial surface by pulldown assay. With this approach, we identified several amino acid residues affecting the strength of Le(b) binding. Additionally, the data showed that the C terminus of BabA, which is predicted to encode an outer membrane β-barrel domain, plays an essential role in the biogenesis of this protein. Helicobacter pylori causes a chronic infection of the human stomach that can lead to ulcers and cancer. The bacterium can bind to gastric epithelial cells with specialized outer membrane proteins. The best-studied protein is the BabA adhesin which binds to the Lewis b blood group antigen. Since H. pylori is a bacterium with very high genetic variability, we asked whether babA evolves during chronic infection and how mutations or recombination in babA affect binding. We found that BabA-mediated adherence was stable in most individuals but observed a complete loss of binding or reduced binding in 22% of individuals. One strain pair in which binding was lost was used to generate babA sequences that were mosaics of a functional allele and a nonfunctional allele, and the mosaic sequences were used to identify amino acids critically involved in binding of BabA to Lewis b.
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Prevalence of the Helicobacter pylori babA2 gene and correlation with the degree of gastritis in infected Slovenian children. Antonie van Leeuwenhoek 2014; 106:637-45. [PMID: 25055876 DOI: 10.1007/s10482-014-0234-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 07/07/2014] [Indexed: 12/16/2022]
Abstract
The aims of our study were to determine the prevalence of the babA2 gene within Helicobacter pylori strains circulating in the Slovenian pediatric population, to further clarify its significance in causing inflammation of gastric mucosa in children and to verify whether cagA, vacA, iceA and babA genes work independently or synergistically in causing gastritis. A total of 163 H. pylori isolates obtained from the same number of children were tested for the presence of cagA, vacA and iceA genes using previously established methods, while the babA2 gene was determined using novel polymerase chain reaction assay targeting a 139-bp fragment of the central region of babA2. The babA2 gene was detected in 47.9% of H. pylori samples. The presence of the babA2 gene was strongly associated with cagA, vacA s1 and vacA m1 genotype. The babA2 status correlated positively with bacterial density score, activity of inflammation and chronic inflammation of gastric mucosa. No significant correlation was found between the babA2 status and the presence of atrophy or intestinal metaplasia. In addition, the activity of gastric inflammation and density score were significantly associated with the coexpression of the cagA, vacA s1, vacA m1 and babA2 genes. The study, which included the largest number of pediatric H. pylori samples to date, confirmed that babA2 gene plays an important role in the pathogenesis of H. pylori gastritis in children. Furthermore, our results suggest that babA2, cagA and vacA s1 and m1 gene products may work synergistically in worsening the inflammation of gastric mucosa.
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The Role of Helicobacter pylori Outer Membrane Proteins in Adherence and Pathogenesis. BIOLOGY 2013; 2:1110-34. [PMID: 24833057 PMCID: PMC3960876 DOI: 10.3390/biology2031110] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 12/12/2022]
Abstract
Helicobacter pylori is one of the most successful human pathogens, which colonizes the mucus layer of the gastric epithelium of more than 50% of the world’s population. This curved, microaerophilic, Gram-negative bacterium induces a chronic active gastritis, often asymptomatic, in all infected individuals. In some cases, this gastritis evolves to more severe diseases such as peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. H. pylori has developed a unique set of factors, actively supporting its successful survival and persistence in its natural hostile ecological niche, the human stomach, throughout the individual’s life, unless treated. In the human stomach, the vast majority of H. pylori cells are motile in the mucus layer lining, but a small percentage adheres to the epithelial cell surfaces. Adherence to the gastric epithelium is important for the ability of H. pylori to cause disease because this intimate attachment facilitates: (1) colonization and persistence, by preventing the bacteria from being eliminated from the stomach, by mucus turnover and gastric peristalsis; (2) evasion from the human immune system and (3) efficient delivery of proteins into the gastric cell, such as the CagA oncoprotein. Therefore, bacteria with better adherence properties colonize the host at higher densities. H. pylori is one of the most genetically diverse bacterial species known and is equipped with an extraordinarily large set of outer membrane proteins, whose role in the infection and persistence process will be discussed in this review, as well as the different receptor structures that have been so far described for mucosal adherence.
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Abstract
Helicobacter pylori (H. pylori) infection is linked to various gastroduodenal diseases; however, only a small fraction of these patients develop associated diseases. Despite the high prevalence of H. pylori infection in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than those in other countries. The incidence of gastric cancer tends to decrease from north to south in East Asia. Such geographical differences in the pathology can be explained, at least in part, by the presence of different types of H. pylori virulence factors in addition to host and environmental factors. Virulence factors of H. pylori, such as CagA, VacA, DupA, IceA, OipA and BabA, have been demonstrated to be the predictors of severe clinical outcomes. Interestingly, a meta-analysis showed that CagA seropositivity was associated with gastric cancer compared with gastritis, even in East Asian countries where almost the strains possess cagA. Another meta-analysis also confirmed the significance of vacA, dupA and iceA. However, it is possible that additional important pathogenic genes may exist because H. pylori consists of approximately 1600 genes. Despite the advances in our understanding of the development of H. pylori infection-related diseases, further work is required to clarify the roles of H. pylori virulence factors.
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Affiliation(s)
- Seiji SHIOTA
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
,Department of General Medicine, Oita University Faculty of Medicine, Yufu-City, Oita, Japan
| | - Rumiko SUZUKI
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
| | - Yoshio YAMAOKA
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
,Department of Medicine-Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas, USA
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Salama NR, Hartung ML, Müller A. Life in the human stomach: persistence strategies of the bacterial pathogen Helicobacter pylori. Nat Rev Microbiol 2013; 11:385-99. [PMID: 23652324 DOI: 10.1038/nrmicro3016] [Citation(s) in RCA: 442] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The bacterial pathogen Helicobacter pylori has co-evolved with humans and colonizes approximately 50% of the human population, but only causes overt gastric disease in a subset of infected hosts. In this Review, we discuss the pathogenesis of H. pylori and the mechanisms it uses to promote persistent colonization of the gastric mucosa, with a focus on recent insights into the role of the virulence factors vacuolating cytotoxin (VacA), cytotoxin-associated gene A (CagA) and CagL. We also describe the immunobiology of H. pylori infection and highlight how this bacterium manipulates the innate and adaptive immune systems of the host to promote its own persistence.
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Affiliation(s)
- Nina R Salama
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Mailstop C3-168, Seattle, Washington 981091024, USA.
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Armitano RI, Matteo MJ, Goldman C, Wonaga A, Viola LA, De Palma GZ, Catalano M. Helicobacter pylori heterogeneity in patients with gastritis and peptic ulcer disease. INFECTION GENETICS AND EVOLUTION 2013; 16:377-85. [PMID: 23523597 DOI: 10.1016/j.meegid.2013.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 02/25/2013] [Accepted: 02/28/2013] [Indexed: 12/14/2022]
Abstract
Genetic diversification allows Helicobacter pylori to persist during chronic colonization/infection. We investigated the intra-host variation of several markers that suggested microevolution in patients with chonic gastritis (CG) and peptic ulcer disease (PUD). One-hundred twenty-six isolates recovered from 14 patients with CG and 13 patients with PUD were analysed. cag pathogenicity island (cagPAI), oipA, vacA, bab gene status and the presence of jhp0926, jhp0945, jhp0947, jhp0949 and jhp0940 genes from the genomic Plasticity Zone (PZ) were taken into accout to investigate intra-host variation. lspA-glmM-RFLP was performed to identify mixed infections. Only one patient was colonised/infected by two ancestrally unrelated strains. Among the 126 isolates, a significant association among cagPAI genotypes, oipA status and vacA alleles was indicated. Complete cagPAI, oipA "on", and vacA s1-m1 variants were significantly found in patients with PUD, without intra-host variations. Isolates from 7/14 patients with CG lacked babA in all chromosomal loci. In contrast, isolates from all or several biopsies of PUD patients carried babA, but in one patient only, the isolates showed positive Lewis b (Leb) binding assay. Considering cagPAI, vacA, oipA, bab genotypes, intra-host variation was also significantly higher in patients with CG. Conversely, a similarly high intra-host variation in almost PZ genes was observed in isolates from patients with CG and PUD. In conclusion, the lowest intra-host variation in cagPAI, oipA, vacA, and bab genes found in patients with PUD suggests the selection of a particular variant along the bacteria-host environment interplay during ulceration development. However, the predominance of this variant may be a refletion of the multifactorial etiology of the disease rather than the cause, as it was also found in patients with CG. The intra-host variation in PZ genes may predict that this genomic region and the other markers of microevolution studied evolve under diverse pressure(s).
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Affiliation(s)
- Rita Inés Armitano
- Instituto de Microbiología y Parasitología Médica (IMPAM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Argentina
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In vivo sequence variation in HopZ, a phase-variable outer membrane protein of Helicobacter pylori. Infect Immun 2012; 80:4364-73. [PMID: 23027539 DOI: 10.1128/iai.00977-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Helicobacter pylori outer membrane protein HopZ is regulated by a phase-variable CT repeat and occurs in two distinct allelic variants. Whole-genome comparisons of isolates from one human volunteer recently provided evidence for in vivo selection for the hopZ ON status. We explored the frequency of sequence variation in hopZ during acute and chronic human infection and studied the association of hopZ with the phylogeographic population structure of H. pylori. hopZ ON variants were cultured from 24 out of 33 volunteers challenged with the hopZ OFF strain BCS 100. Transmission of H. pylori within families was also frequently associated with a status change of hopZ. In contrast, hopZ sequences obtained from 26 sets of sequential isolates from chronically infected individuals showed no changes of status, suggesting that the hopZ status selected during early infection is subsequently stable. Mutations leading to amino acid changes in HopZ occurred more frequently in ON than in OFF status isolates during chronic infection, indicating that sequence changes are more likely the result of positive selection in ON isolates than of a loss of negative selection pressure in OFF isolates. Analysis of 63 isolates from chronically infected individuals revealed no significant correlation of hopZ status with chronic atrophic gastritis. hopZ sequences were obtained from a globally representative collection of 54 H. pylori strains. All H. pylori populations contained hopZ-positive isolates. The data suggest that hopZ has been acquired and split into the two variants before the human migration out of Africa.
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Kumar R, Mukhopadhyay AK, Ghosh P, Rao DN. Comparative transcriptomics of H. pylori strains AM5, SS1 and their hpyAVIBM deletion mutants: possible roles of cytosine methylation. PLoS One 2012; 7:e42303. [PMID: 22879937 PMCID: PMC3411764 DOI: 10.1371/journal.pone.0042303] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 07/05/2012] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori is an important human pathogen and one of the most successful chronic colonizers of the human body. H. pylori uses diverse mechanisms to modulate its interaction with the host in order to promote chronic infection and overcome host immune response. Restriction-modification genes are a major part of strain-specific genes present in H. pylori. The role of N6 - adenine methylation in bacterial gene regulation and virulence is well established but not much is known about the effect of C5 -cytosine methylation on gene expression in prokaryotes. In this study, it was observed by microarray analysis and RT-PCR, that deletion of an orphan C5 -cytosine methyltransferase, hpyAVIBM in H. pylori strains AM5and SS1 has a significant effect on the expression of number of genes belonging to motility, adhesion and virulence. AM5ΔhpyAVIBM mutant strain has a different LPS profile and is able to induce high IL-8 production compared to wild-type. hpyAVIBM from strain 26695 is able to complement mutant SS1 and AM5 strains. This study highlights a possible significance of cytosine methylation in the physiology of H. pylori.
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Affiliation(s)
- Ritesh Kumar
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Asish K. Mukhopadhyay
- Division of Bacteriology, National Institute of Cholera and Enteric Disease, Kolkata, India
| | - Prachetash Ghosh
- Division of Bacteriology, National Institute of Cholera and Enteric Disease, Kolkata, India
| | - Desirazu N. Rao
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
- * E-mail:
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Sheu SM, Sheu BS, Chiang WC, Kao CY, Wu HM, Yang HB, Wu JJ. H. pylori clinical isolates have diverse babAB genotype distributions over different topographic sites of stomach with correlation to clinical disease outcomes. BMC Microbiol 2012; 12:89. [PMID: 22646246 PMCID: PMC3444412 DOI: 10.1186/1471-2180-12-89] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 05/30/2012] [Indexed: 12/13/2022] Open
Abstract
Background Intragenomic recombination between babA and babB mediates antigenic variations and may help H. pylori colonization. This study determined whether variable genotypes of babA and babB correlate to different clinical disease outcomes, and can distribute over the different gastric niches. Results This study enrolled 92 clinical strains (45 from peptic ulcer, 27 from gastritis, and 20 from gastric cancer) to detect whether the babA and babB are at locus A or B by PCR reactions using the primers designed from the upstream and variable region of the babA and babB genes. Four genotypes of babA and babB (A B, AB B, A AB, AB AB) were found. The distribution of the 4 genotypes in 92 clinical strains was significantly different among patients with different gastric diseases (p < 0.05). The isolates from gastric cancer patients had a higher rate of AB AB genotype than those from non-cancer patients (40.0% vs. 9.7%, p < 0.05). The AB AB genotype was associated with a higher intensity of intestinal metaplasia (p < 0.05), but did not correlate with a higher inflammation and colonization density in gastric histology (p > 0.05). Besides, the study enrolled 19 patients to verify whether variable genotypes of babAB existed in the different gastric niches. Among the patients infected with more than one babAB genotypes over antrum and corpus, there were higher rate of genotypes as A B or AB AB in isolates from antrum than in those from corpus (75.0 % vs. 16.7%, p < 0.05). Conclusions The H. pylori isolate with the AB AB genotype correlates with an increased gastric cancer risk, and colonize in an antrum predominant manner.
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Affiliation(s)
- Shew-Meei Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University, 138 Sheng Li Road, Tainan, Taiwan
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Talarico S, Whitefield SE, Fero J, Haas R, Salama NR. Regulation of Helicobacter pylori adherence by gene conversion. Mol Microbiol 2012; 84:1050-61. [PMID: 22519812 DOI: 10.1111/j.1365-2958.2012.08073.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Genetic diversification of Helicobacter pylori adhesin genes may allow adaptation of adherence properties to facilitate persistence despite host defences. The sabA gene encodes an adhesin that binds sialyl-Lewis antigens on inflamed gastric tissue. We found variability in the copy number and locus of the sabA gene and the closely related sabB and omp27 genes due to gene conversion among 51 North American paediatric H. pylori strains. We determined that sabB to sabA gene conversion is predominantly the result of intra-genomic recombination and RecA, RecG and AddA influence the rate at which it occurs. Although all clinical strains had at least one sabA gene copy, sabA and sabB were lost due to gene conversion at similar rates in vitro, suggesting host selection to maintain the sabA gene. sabA gene duplication resulted in increased SabA protein production and increased adherence to sialyl-Lewis antigens and mouse gastric tissue. In conclusion, gene conversion is a mechanism for H. pylori to regulate sabA expression level and adherence.
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Affiliation(s)
- Sarah Talarico
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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35
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Ren L, Liao Y, Song Y, Guo Y, Mao X, Xie Q, Zhang W, Guo G, Zou Q. High frequency variations of Helicobacter pylori isolates in individual hosts in a Chinese population. Int J Infect Dis 2012; 16:e358-63. [DOI: 10.1016/j.ijid.2012.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 01/05/2012] [Accepted: 01/12/2012] [Indexed: 01/27/2023] Open
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Abstract
All organisms have pathways that repair the genome, ensuring their survival and that of their progeny. But these pathways also serve to diversify the genome, causing changes at the nucleotide, whole gene, and genome structure levels. Sequencing of bacteria has revealed wide allelic diversity and differences in gene content within the same species, highlighting the importance of understanding pathways of recombination and DNA repair. The human stomach pathogen Helicobacter pylori is an excellent model system for studying these pathways. H. pylori harbors major recombination and repair pathways and is naturally competent, facilitating its ability to diversify its genome. Elucidation of DNA recombination, repair, and diversification programs in this pathogen will reveal connections between these pathways and their importance to infection.
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Affiliation(s)
- Marion S Dorer
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
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37
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Matteo MJ, Armitano RI, Romeo M, Wonaga A, Olmos M, Catalano M. Helicobacter pylori bab genes during chronic colonization. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2011; 2:286-291. [PMID: 21915366 PMCID: PMC3166155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 07/06/2011] [Indexed: 05/31/2023]
Abstract
Helicobacter pylori BabA adhesin metastability could yield variants with potential for periodic activation and deactivation of their mediated adherence. babA/B or babB/A chimeras could play an important role in translational regulation. We investigated the frequency of different bab gene profiles in paired isolates from antrum and corpus recovered from patients with chronic gastritis. Isolates from 174 biopsies from 34 patients were included, and bab genes at the three common chromosomal loci were investigated. Inter-micro-niche variation was found in 1/4 patients, counting duplicate copies of babA or babB, babB/A or babA/B chimeras, opposite location of babA and babB or babC and babB, and absence of babB ATG translational codon. Truncated BabA was identified in 2/34 patients without inter-micro-niche variation. Isolates from 12/34 patients harbored babA/B or babB/A chimeras -either in one, several or all micro-niches indicating that chimera formation is a common mechanism to control BabA expression. To note, babA gene was absent in 11/34 patients, and in this population, babA/B chimeras which lack expression predominated over babB/A, able to exhibit Le(b) binding phenotype.
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Affiliation(s)
- Mario J Matteo
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Rita I Armitano
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Mariela Romeo
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Andres Wonaga
- Servicio de Gastroenterología, Clínica BazterricaBuenos Aires, Argentina
| | - Martín Olmos
- Servicio de Endoscopía, Hospital General de Agudos Juan A FernándezBuenos Aires, Argentina
| | - Mariana Catalano
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos AiresBuenos Aires, Argentina
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Skoog EC, Lindberg M, Lindén SK. Strain-dependent proliferation in response to human gastric mucin and adhesion properties of Helicobacter pylori are not affected by co-isolated Lactobacillus sp. Helicobacter 2011; 16:9-19. [PMID: 21241407 DOI: 10.1111/j.1523-5378.2010.00810.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Helicobacter pylori colonize the mucus layer that covers the gastric epithelium and can cause gastritis, ulcers, and gastric cancer. Recently, Lactobacillus sp. have also been found to reside in this niche permanently. This study compares adhesive properties and proliferation of co-isolated lactobacilli and H. pylori in the presence of mucins and investigates possibilities for lactobacilli-mediated inhibition of H. pylori. MATERIALS AND METHODS Binding and proliferation of four H. pylori and four Lactobacillus strains, simultaneously isolated after residing in the stomachs of four patients for >4 years, to human gastric mucins were investigated using microtiter-based methods. RESULTS The H. pylori strains co-isolated with lactobacilli exhibited the same mucin binding properties as demonstrated for H. pylori strains previously. In contrast, no binding to mucins was detected with the Lactobacillus strains. Proliferation of mucin-binding H. pylori strains was stimulated by the presence of mucins, whereas proliferation of non-binding H. pylori and Lactobacillus strains was unaffected. Associative cultures of co-isolated H. pylori and Lactobacillus strains showed no inhibition of H. pylori proliferation because of the presence of whole bacteria or supernatant of lactobacilli. CONCLUSIONS The presence of lactobacilli in the stomach did not select for different mucin binding properties of H. pylori, and Lactobacillus sp. did neither compete for binding sites nor inhibit the growth of co-isolated H. pylori. The effects of human gastric mucins on H. pylori proliferation vary between strains, and the host-bacteria interaction in the mucus niche thus depends on both the H. pylori strain and the microenvironment provided by the host mucins.
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Affiliation(s)
- Emma C Skoog
- Mucosal Immunobiology and Vaccine Center, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
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39
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Ohno T, Vallström A, Rugge M, Ota H, Graham DY, Arnqvist A, Yamaoka Y. Effects of blood group antigen-binding adhesin expression during Helicobacter pylori infection of Mongolian gerbils. J Infect Dis 2011; 203:726-35. [PMID: 21227917 DOI: 10.1093/infdis/jiq090] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori outer membrane proteins, such as the blood group antigen-binding adhesin (BabA), are associated with severe pathological outcomes. However, the in vivo role of BabA during long-term infection is not clear. In this study, Mongolian gerbils were infected with H. pylori and necropsied continuously during 18 months. Bacterial clones were recovered and analyzed for BabA expression, Leb-binding activity, and adhesion to gastric mucosa. BabA expression was completely absent by 6 months post-infection. Loss of BabA expression was attributable to nucleotide changes within the babA gene that resulted in a truncated BabA. In response to the infection, changes in the epithelial glycosylation pattern were observed that were similar to responses observed in humans and monkeys. Furthermore, infections with BabA-expressing and BabA-nonexpressing H. pylori showed no differences in colonization, but infection with the BabA-expressing strain exhibited histological changes and increased inflammatory cell infiltration. This suggests that BabA expression contributes to severe mucosal injury.
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Affiliation(s)
- Tomoyuki Ohno
- Department of Medicine-Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas 77030, USA
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40
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Moore ME, Borén T, Solnick JV. Life at the margins: modulation of attachment proteins in Helicobacter pylori. Gut Microbes 2011; 2:42-6. [PMID: 21637017 PMCID: PMC3225796 DOI: 10.4161/gmic.2.1.14626] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Helicobacter pylori is the primary cause of peptic ulcer disease and is estimated to account for about 60% of all cases of gastric cancer, the second most common cause of cancer death worldwide. Among the H. pylori virulence factors associated with disease, in addition to the well-known cag pathogenicity island, is the BabA adhesin, an outer membrane protein that binds with high affinity to fucosylated glycans on the gastric epithelium, such as Lewis B (Le(b)) and related terminal fucose residues found on the blood group O (H antigen), A and B antigens. BabA-mediated attachment to the gastric mucosa promotes chronic inflammation and gastric pathology, which from the bacterial perspective carries both risks and benefits. We recently described modulation in expression of BabA and related outer membrane proteins that occurs during colonization of experimental animals. Here we put these findings into a broader context, and speculate on their implications for the host-pathogen relationship.
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Affiliation(s)
- Mary E Moore
- Departments of Medicine and Microbiology and Immunology; Center for Comparative Medicine; California National Primate Research Center; University of California; Davis School of Medicine; Davis, CA USA
| | - Thomas Borén
- Department of Medical Biochemistry and Biophysics; Umeå University; Umeå, Sweden
| | - Jay V Solnick
- Departments of Medicine and Microbiology and Immunology; Center for Comparative Medicine; California National Primate Research Center; University of California; Davis School of Medicine; Davis, CA USA
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41
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Allison CC, Ferrero RL. Role of virulence factors and host cell signaling in the recognition of Helicobacter pylori and the generation of immune responses. Future Microbiol 2010; 5:1233-55. [PMID: 20722601 DOI: 10.2217/fmb.10.84] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori colonizes a large proportion of the world's population, with infection invariably leading to chronic, lifelong gastritis. While the infection often persists undiagnosed and without causing severe pathology, there are a number of host, bacterial and environmental factors that can influence whether infection provokes a mild inflammatory response or results in significant morbidity. Intriguingly, the most virulent H. pylori strains appear to deliberately induce the epithelial signaling cascades responsible for activating the innate immune system. While the reason for this remains unclear, the resulting adaptive immune responses are largely ineffective in clearing the bacterium once infection has become established and, as a result, inflammation likely causes more damage to the host itself.
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Affiliation(s)
- Cody C Allison
- Centre for Innate Immunity & Infectious Diseases, Monash Institute of Medical Research, Clayton, Australia.
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42
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Thiberge JM, Boursaux-Eude C, Lehours P, Dillies MA, Creno S, Coppée JY, Rouy Z, Lajus A, Ma L, Burucoa C, Ruskoné-Foumestraux A, Courillon-Mallet A, De Reuse H, Boneca IG, Lamarque D, Mégraud F, Delchier JC, Médigue C, Bouchier C, Labigne A, Raymond J. From array-based hybridization of Helicobacter pylori isolates to the complete genome sequence of an isolate associated with MALT lymphoma. BMC Genomics 2010; 11:368. [PMID: 20537153 PMCID: PMC3091627 DOI: 10.1186/1471-2164-11-368] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 06/10/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Helicobacter pylori infection is associated with several gastro-duodenal inflammatory diseases of various levels of severity. To determine whether certain combinations of genetic markers can be used to predict the clinical source of the infection, we analyzed well documented and geographically homogenous clinical isolates using a comparative genomics approach. RESULTS A set of 254 H. pylori genes was used to perform array-based comparative genomic hybridization among 120 French H. pylori strains associated with chronic gastritis (n = 33), duodenal ulcers (n = 27), intestinal metaplasia (n = 17) or gastric extra-nodal marginal zone B-cell MALT lymphoma (n = 43). Hierarchical cluster analyses of the DNA hybridization values allowed us to identify a homogeneous subpopulation of strains that clustered exclusively with cagPAI minus MALT lymphoma isolates. The genome sequence of B38, a representative of this MALT lymphoma strain-cluster, was completed, fully annotated, and compared with the six previously released H. pylori genomes (i.e. J99, 26695, HPAG1, P12, G27 and Shi470). B38 has the smallest H. pylori genome described thus far (1,576,758 base pairs containing 1,528 CDSs); it contains the vacAs2m2 allele and lacks the genes encoding the major virulence factors (absence of cagPAI, babB, babC, sabB, and homB). Comparative genomics led to the identification of very few sequences that are unique to the B38 strain (9 intact CDSs and 7 pseudogenes). Pair-wise genomic synteny comparisons between B38 and the 6 H. pylori sequenced genomes revealed an almost complete co-linearity, never seen before between the genomes of strain Shi470 (a Peruvian isolate) and B38. CONCLUSION These isolates are deprived of the main H. pylori virulence factors characterized previously, but are nonetheless associated with gastric neoplasia.
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Affiliation(s)
- Jean-Michel Thiberge
- Institut Pasteur, Unité postulante de Pathogenèse de Helicobacter, Paris, France
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43
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From array-based hybridization of Helicobacter pylori isolates to the complete genome sequence of an isolate associated with MALT lymphoma. BMC Genomics 2010. [PMID: 20537153 DOI: 10.1186/1471-2164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Helicobacter pylori infection is associated with several gastro-duodenal inflammatory diseases of various levels of severity. To determine whether certain combinations of genetic markers can be used to predict the clinical source of the infection, we analyzed well documented and geographically homogenous clinical isolates using a comparative genomics approach. RESULTS A set of 254 H. pylori genes was used to perform array-based comparative genomic hybridization among 120 French H. pylori strains associated with chronic gastritis (n = 33), duodenal ulcers (n = 27), intestinal metaplasia (n = 17) or gastric extra-nodal marginal zone B-cell MALT lymphoma (n = 43). Hierarchical cluster analyses of the DNA hybridization values allowed us to identify a homogeneous subpopulation of strains that clustered exclusively with cagPAI minus MALT lymphoma isolates. The genome sequence of B38, a representative of this MALT lymphoma strain-cluster, was completed, fully annotated, and compared with the six previously released H. pylori genomes (i.e. J99, 26695, HPAG1, P12, G27 and Shi470). B38 has the smallest H. pylori genome described thus far (1,576,758 base pairs containing 1,528 CDSs); it contains the vacAs2m2 allele and lacks the genes encoding the major virulence factors (absence of cagPAI, babB, babC, sabB, and homB). Comparative genomics led to the identification of very few sequences that are unique to the B38 strain (9 intact CDSs and 7 pseudogenes). Pair-wise genomic synteny comparisons between B38 and the 6 H. pylori sequenced genomes revealed an almost complete co-linearity, never seen before between the genomes of strain Shi470 (a Peruvian isolate) and B38. CONCLUSION These isolates are deprived of the main H. pylori virulence factors characterized previously, but are nonetheless associated with gastric neoplasia.
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Magalhães A, Reis CA. Helicobacter pylori adhesion to gastric epithelial cells is mediated by glycan receptors. Braz J Med Biol Res 2010; 43:611-8. [PMID: 20521012 DOI: 10.1590/s0100-879x2010007500049] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Accepted: 05/24/2010] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori adhesion to gastric epithelial cells constitutes a key step in the establishment of a successful infection of the gastric mucosa. The high representation of outer membrane proteins in the bacterial genome suggests the relevance of those proteins in the establishment of profitable interactions with the host gastric cells. Gastric epithelial cells are protected by a mucous layer gel, mainly consisting of the MUC5AC and MUC6 mucins. In addition to this protective role, mucins harbor glycan-rich domains that constitute preferential binding sites of many pathogens. In this article we review the main players in the process of H. pylori adhesion to gastric epithelial cells, which contribute decisively to the high prevalence and chronicity of H. pylori infection. The BabA adhesin recognizes both H-type 1 and Lewis b blood-group antigens expressed on normal gastric mucosa of secretor individuals, contributing to the initial steps of infection. Upon colonization, persistent infection induces an inflammatory response with concomitant expression of sialylated antigens. The SabA adhesin mediates H. pylori binding to inflamed gastric mucosa by recognizing sialyl-Lewis a and sialyl-Lewis x antigens. The expression of the BabA and SabA adhesins is tightly regulated, permitting the bacteria to rapidly adapt to the changes of glycosylation of the host gastric mucosa that occur during infection, as well as to escape from the inflammatory response. The growing knowledge of the interactions between the bacterial adhesins and the host receptors will contribute to the design of alternative strategies for eradication of the infection.
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Affiliation(s)
- A Magalhães
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal
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Expression of the BabA adhesin during experimental infection with Helicobacter pylori. Infect Immun 2010; 78:1593-600. [PMID: 20123715 DOI: 10.1128/iai.01297-09] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Helicobacter pylori babA gene encodes an outer membrane protein that mediates binding to fucosylated ABH antigens of the ABO blood group. We recently demonstrated that BabA expression is lost during experimental infection of rhesus macaques with H. pylori J166. We sought to test the generality of this observation by comparison of different H. pylori strains and different animal hosts. Challenge of macaques with H. pylori J99 yielded output strains that lost BabA expression, either by selection and then expansion of a subpopulation of J99 that had a single-base-pair mutation that encoded a stop codon or by gene conversion of babA with a duplicate copy of babB, a paralog of unknown function. Challenge of mice with H. pylori J166, which unlike J99, has 5' CT repeats in babA, resulted in loss of BabA expression due to phase variation. In the gerbil, Leb binding was lost by replacement of the babA gene that encoded Leb binding with a nonbinding allele that differed at six amino acid residues. Complementation experiments confirmed that change in these six amino acids of BabA was sufficient to eliminate binding to Leb and to gastric tissue. These results demonstrate that BabA expression in vivo is highly dynamic, and the findings implicate specific amino acid residues as critical for binding to fucosylated ABH antigens. We hypothesize that modification of BabA expression during H. pylori infection is a mechanism to adapt to changing conditions of inflammation and glycan expression at the epithelial surface.
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Outer membrane protein expression profile in Helicobacter pylori clinical isolates. Infect Immun 2009; 77:3782-90. [PMID: 19546190 DOI: 10.1128/iai.00364-09] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The gram-negative gastric pathogen Helicobacter pylori is equipped with an extraordinarily large set of outer membrane proteins (OMPs), whose role in the infection process is not well understood. The Hop (Helicobacter outer membrane porins) and Hor (Hop-related proteins) groups constitute a large paralogous family consisting of 33 members. The OMPs AlpA, AlpB, BabA, SabA, and HopZ have been identified as adhesins or adherence-associated proteins. To better understand the relevance of these and other OMPs during infection, we analyzed the expression of eight different omp genes (alpA, alpB, babA, babB, babC, sabA, hopM, and oipA) in a set of 200 patient isolates, mostly from symptomatic children or young adults. Virtually all clinical isolates produced the AlpA and AlpB proteins, supporting their essential function. All other OMPs were produced at extremely variable rates, ranging from 35% to 73%, indicating a function in close adaptation to the individual host or gastric niche. In 11% of the isolates, BabA was produced, and SabA was produced in 5% of the isolates, but the strains failed to bind their cognate substrates. Interleukin-8 (IL-8) expression in gastric cells was strictly dependent on the presence of the cag pathogenicity island, whereas the presence of OipA clearly enhanced IL-8 production. The presence of the translocated effector protein CagA correlated well with BabA and OipA production. In conclusion, we found unexpectedly diverse omp expression profiles in individual H. pylori strains and hypothesize that this reflects the selective pressure for adhesion, which may differ across different hosts as well as within an individual over time.
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Paniagua GL, Monroy E, Rodríguez R, Arroniz S, Rodríguez C, Cortés JL, Camacho A, Negrete E, Vaca S. Frequency of vacA, cagA and babA2 virulence markers in Helicobacter pylori strains isolated from Mexican patients with chronic gastritis. Ann Clin Microbiol Antimicrob 2009; 8:14. [PMID: 19405980 PMCID: PMC2683802 DOI: 10.1186/1476-0711-8-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 04/30/2009] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and it is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in 238 adult patients, from a marginal urban area of Mexico, with chronic gastritis. METHODS H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR. RESULTS H. pylori-positive biopsies were 143 (60.1%). All H. pylori strains were vacA+; 39.2% were cagA+; 13.3% were cagA+ babA2+ and 8.4% were babA2+. Mexican strains examined possessed the vacA s1, m1 (43.4%), s1, m2 (24.5%), s2, m1 (20.3%) and s2, m2 (11.9%) genotypes. CONCLUSION These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Forty four percent (63/143) of the H. pylori strains analyzed in this work may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143). However, a statistically significant correlation was not observed between vacAs1, cagA and babA2 virulence markers (chi2 test; P > 0.05).
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Affiliation(s)
- Gloria Luz Paniagua
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
| | - Eric Monroy
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
| | - Raymundo Rodríguez
- Hospital General Regional 72 del Instituto Mexicano del Seguro Social, Av. G. Baz s/n, Tlanepantla, 54000, Estado de Mexico, Mexico
| | - Salvador Arroniz
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
| | - Cristina Rodríguez
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
| | - José Luis Cortés
- Hospital General Regional 72 del Instituto Mexicano del Seguro Social, Av. G. Baz s/n, Tlanepantla, 54000, Estado de Mexico, Mexico
| | - Ausencio Camacho
- Hospital General Regional 72 del Instituto Mexicano del Seguro Social, Av. G. Baz s/n, Tlanepantla, 54000, Estado de Mexico, Mexico
| | - Erasmo Negrete
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
| | - Sergio Vaca
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de Mexico, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de Mexico, Mexico
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Abstract
Helicobacter pylori infection is the most important risk factor in the development of non-cardia gastric adenocarcinoma; host genetic variability and dietary co-factors also modulate risk. Because most H. pylori infections do not cause cancer, H. pylori heterogeneity has been investigated to identify possible virulence factors. The strongest candidates are genes within the cag (cytotoxin-associated antigen) pathogenicity island, including the gene encoding the CagA protein, as well as polymorphic variation in the VacA vacuolating exotoxin and the blood group antigen binding adhesin BabA. Improved understanding of the pathogenesis of H. pylori-associated gastric cancer may improve risk stratification for prevention and therapy.
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Affiliation(s)
- Sicheng Wen
- Department of Medicine, Division of Gastroenterology, Rhode Island Hospital and Brown University, 593 Eddy Street, Providence, RI 02903, USA
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Wen S, Moss SF. Helicobacter pylori virulence factors in gastric carcinogenesis. Cancer Lett 2008; 282:1-8. [PMID: 19111390 DOI: 10.1016/j.canlet.2008.11.016] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/10/2008] [Accepted: 11/17/2008] [Indexed: 02/09/2023]
Abstract
Helicobacter pylori infection is the most important risk factor in the development of non-cardia gastric adenocarcinoma; host genetic variability and dietary co-factors also modulate risk. Because most H. pylori infections do not cause cancer, H. pylori heterogeneity has been investigated to identify possible virulence factors. The strongest candidates are genes within the cag (cytotoxin-associated antigen) pathogenicity island, including the gene encoding the CagA protein, as well as polymorphic variation in the VacA vacuolating exotoxin and the blood group antigen binding adhesin BabA. Improved understanding of the pathogenesis of H. pylori-associated gastric cancer may improve risk stratification for prevention and therapy.
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Affiliation(s)
- Sicheng Wen
- Department of Medicine, Division of Gastroenterology, Rhode Island Hospital and Brown University, 593 Eddy Street, Providence, RI 02903, USA
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Amundsen SK, Fero J, Hansen LM, Cromie GA, Solnick JV, Smith GR, Salama NR. Helicobacter pylori AddAB helicase-nuclease and RecA promote recombination-related DNA repair and survival during stomach colonization. Mol Microbiol 2008; 69:994-1007. [PMID: 18573180 DOI: 10.1111/j.1365-2958.2008.06336.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Helicobacter pylori colonization of the human stomach is characterized by profound disease-causing inflammation. Bacterial proteins that detoxify reactive oxygen species or recognize damaged DNA adducts promote infection, suggesting that H. pylori requires DNA damage repair for successful in vivo colonization. The molecular mechanisms of repair remain unknown. We identified homologues of the AddAB class of helicase-nuclease enzymes, related to the Escherichia coli RecBCD enzyme, which, with RecA, is required for repair of DNA breaks and homologous recombination. H. pylori mutants lacking addA or addB genes lack detectable ATP-dependent nuclease activity, and the cloned H. pylori addAB genes restore both nuclease and helicase activities to an E. coli recBCD deletion mutant. H. pylori addAB and recA mutants have a reduced capacity for stomach colonization. These mutants are sensitive to DNA damaging agents and have reduced frequencies of apparent gene conversion between homologous genes encoding outer membrane proteins. Our results reveal requirements for double-strand break repair and recombination during both acute and chronic phases of H. pylori stomach infection.
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Affiliation(s)
- Susan K Amundsen
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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