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Tong Q, Yin C, Hang X, Bai Y, Zhang C, Xu J, Huang Y, Ge Y, Chen T, Zeng L, Jia J, Bi H. Loureirin A is a narrow-spectrum antimicrobial agent against Helicobacter pylori. Antimicrob Agents Chemother 2024:e0031424. [PMID: 38656185 DOI: 10.1128/aac.00314-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 03/31/2024] [Indexed: 04/26/2024] Open
Abstract
Currently, Helicobacter pylori eradication by antibiotic therapy faces various challenges, including antibiotic resistance, side effects on intestinal commensal bacteria, and patient compliance. In this study, loureirin A (LrA), a traditional Chinese medicine monomer extracted from Sanguis Draconis flavones, was found to possess specific antibacterial activity against H. pylori without the bacteria displaying a tendency to develop resistance in vitro. LrA demonstrated a synergistic or additive effect when combined with omeprazole (a proton pump inhibitor) against H. pylori. The combination of LrA and omeprazole showed promising anti-H. pylori potential, exhibiting notable in vivo efficacy comparable to standard triple therapy in mouse models infected with both drug-sensitive and drug-resistant H. pylori strains. Moreover, the narrow-spectrum antibacterial profile of LrA is reflected in its minimal effect on the diversity and composition of the mouse gut microbiota. The underlying mechanism of action of LrA against H. pylori involves the generation of bactericidal levels of reactive oxygen species, resulting in apoptosis-like cell death. These findings indicate that LrA is a promising lead compound targeting H. pylori without harming the commensal bacteria.
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Affiliation(s)
- Qian Tong
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Chengqiang Yin
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xudong Hang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yuefan Bai
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Chongwen Zhang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Jingcheng Xu
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yan Huang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yixin Ge
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Tianyu Chen
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Liping Zeng
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Jia Jia
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Hongkai Bi
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
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Nguyen TKC, Do HDK, Nguyen TLP, Pham TT, Mach BN, Nguyen TC, Pham TL, Katsande PM, Hong HA, Duong HT, Phan AN, Cutting SM, Vu MT, Nguyen VD. Genomic and vaccine preclinical studies reveal a novel mouse-adapted Helicobacter pylori model for the hpEastAsia genotype in Southeast Asia. J Med Microbiol 2024; 73. [PMID: 38235783 DOI: 10.1099/jmm.0.001786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024] Open
Abstract
Introduction. Helicobacter pylori infection is a major global health concern, linked to the development of various gastrointestinal diseases, including gastric cancer. To study the pathogenesis of H. pylori and develop effective intervention strategies, appropriate animal pathogen models that closely mimic human infection are essential.Gap statement. This study focuses on the understudied hpEastAsia genotype in Southeast Asia, a region marked by a high H. pylori infection rate. No mouse-adapted model strains has been reported previously. Moreover, it recognizes the urgent requirement for vaccines in developing countries, where overuse of antimicrobials is fuelling the emergence of resistance.Aim. This study aims to establish a novel mouse-adapted H. pylori model specific to the hpEastAsia genotype prevalent in Southeast Asia, focusing on comparative genomic and histopathological analysis of pathogens coupled with vaccine preclinical studies.Methodology. We collected and sequenced the whole genome of clinical strains of H. pylori from infected patients in Vietnam and performed comparative genomic analyses of H. pylori strains in Southeast Asia. In parallel, we conducted preclinical studies to assess the pathogenicity of the mouse-adapted H. pylori strain and the protective effect of a new spore-vectored vaccine candidate on male Mlac:ICR mice and the host immune response in a female C57BL/6 mouse model.Results. Genome sequencing and comparison revealed unique and common genetic signatures, antimicrobial resistance genes and virulence factors in strains HP22 and HP34; and supported clarithromycin-resistant HP34 as a representation of the hpEastAsia genotype in Vietnam and Southeast Asia. HP34-infected mice exhibited gastric inflammation, epithelial erosion and dysplastic changes that closely resembled the pathology observed in human H. pylori infection. Furthermore, comprehensive immunological characterization demonstrated a robust host immune response, including both mucosal and systemic immune responses. Oral vaccination with candidate vaccine formulations elicited a significant reduction in bacterial colonization in the model.Conclusion. Our findings demonstrate the successful development of a novel mouse-adapted H. pylori model for the hpEastAsia genotype in Vietnam and Southeast Asia. Our research highlights the distinctive genotype and pathogenicity of clinical H. pylori strains in the region, laying the foundation for targeted interventions to address this global health burden.
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Affiliation(s)
- Thi Kim Cuc Nguyen
- Institute of Biotechnology and Environment, Nha Trang University, 2 Nguyen Dinh Chieu Street, Khanh Hoa, Vietnam
| | - Hoang Dang Khoa Do
- NTT Hi-tech Institute, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, Ho Chi Minh City, Vietnam
| | - Thi Lan Phuong Nguyen
- Institute of Vaccines and Biological Medicals (IVAC), 9 Pasteur Street, Nha Trang, Khanh Hoa, Vietnam
| | - Thu Thuy Pham
- Institute of Biotechnology and Environment, Nha Trang University, 2 Nguyen Dinh Chieu Street, Khanh Hoa, Vietnam
| | - Bao Ngoc Mach
- NTT Hi-tech Institute, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, Ho Chi Minh City, Vietnam
| | - Thi Chinh Nguyen
- Institute of Biotechnology and Environment, Nha Trang University, 2 Nguyen Dinh Chieu Street, Khanh Hoa, Vietnam
| | - Thi Lan Pham
- Institute of Biotechnology and Environment, Nha Trang University, 2 Nguyen Dinh Chieu Street, Khanh Hoa, Vietnam
| | - Paidamoyo M Katsande
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Huynh Anh Hong
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Huu Thai Duong
- Institute of Vaccines and Biological Medicals (IVAC), 9 Pasteur Street, Nha Trang, Khanh Hoa, Vietnam
| | - Anh N Phan
- School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Simon M Cutting
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Minh Thiet Vu
- NTT Hi-tech Institute, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, Ho Chi Minh City, Vietnam
| | - Van Duy Nguyen
- Institute of Biotechnology and Environment, Nha Trang University, 2 Nguyen Dinh Chieu Street, Khanh Hoa, Vietnam
- School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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O’Brien VP, Jackson LK, Frick JP, Rodriguez Martinez AE, Jones DS, Johnston CD, Salama NR. Helicobacter pylori Chronic Infection Selects for Effective Colonizers of Metaplastic Glands. mBio 2023; 14:e0311622. [PMID: 36598261 PMCID: PMC9973278 DOI: 10.1128/mbio.03116-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/05/2022] [Indexed: 01/05/2023] Open
Abstract
Chronic gastric infection with Helicobacter pylori can lead to progressive tissue changes that culminate in cancer, but how H. pylori adapts to the changing tissue environment during disease development is not fully understood. In a transgenic mouse gastric metaplasia model, we found that strains from unrelated individuals differed in their ability to infect the stomach, to colonize metaplastic glands, and to alter the expression of the metaplasia-associated protein TFF3. H. pylori isolates from different stages of disease from a single individual had differential ability to colonize healthy and metaplastic gastric glands. Exposure to the metaplastic environment selected for high gastric colonization by one of these strains. Complete genome sequencing revealed a unique alteration in the frequency of a variant allele of the putative adhesin sabB, arising from a recombination event with the related sialic acid binding adhesin (SabA) gene. Mutation of sabB in multiple H. pylori strain backgrounds strongly reduced adherence to both normal and metaplastic gastric tissue, and highly attenuated stomach colonization in mice. Thus, the changing gastric environment during disease development promotes bacterial adhesin gene variation associated with enhanced gastric colonization. IMPORTANCE Chronic infection with Helicobacter pylori is the primary risk factor for developing stomach cancer. As disease progresses H. pylori must adapt to a changing host tissue environment that includes induction of new cell fates in the cells that line the stomach. We tested representative H. pylori isolates collected from the same patient during early and later stages of disease in a mouse model where we can rapidly induce disease-associated tissue changes. Only the later-stage H. pylori strains could robustly colonize the diseased stomach environment. We also found that the ability to colonize the diseased stomach was associated with genetic variation in a putative cell surface adhesin gene called sabB. Additional experiments revealed that SabB promotes binding to stomach tissue and is critical for stomach colonization by the late-stage strains. Thus, H. pylori diversifies its genome during disease progression and these genomic changes highlight critical factors for bacterial persistence.
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Affiliation(s)
- V. P. O’Brien
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - L. K. Jackson
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, USA
| | - J. P. Frick
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | | | - D. S. Jones
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - C. D. Johnston
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - N. R. Salama
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
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Freire de Melo F, Marques HS, Fellipe Bueno Lemos F, Silva Luz M, Rocha Pinheiro SL, de Carvalho LS, Souza CL, Oliveira MV. Role of nickel-regulated small RNA in modulation of Helicobacter pylori virulence factors. World J Clin Cases 2022; 10:11283-11291. [PMID: 36387830 PMCID: PMC9649571 DOI: 10.12998/wjcc.v10.i31.11283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/14/2022] [Accepted: 09/06/2022] [Indexed: 02/05/2023] Open
Abstract
Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects about half of the world's population. H. pylori infection prevails by several mechanisms of adaptation of the bacteria and by its virulence factors including the cytotoxin associated antigen A (CagA). CagA is an oncoprotein that is the protagonist of gastric carcinogenesis associated with prolonged H. pylori infection. In this sense, small regulatory RNAs (sRNAs) are important macromolecules capable of inhibiting and activating gene expression. This function allows sRNAs to act in adjusting to unstable environmental conditions and in responding to cellular stresses in bacterial infections. Recent discoveries have shown that nickel-regulated small RNA (NikS) is a post-transcriptional regulator of virulence properties of H. pylori, including the oncoprotein CagA. Notably, high concentrations of nickel cause the reduction of NikS expression and consequently this increases the levels of CagA. In addition, NikS expression appears to be lower in clinical isolates from patients with gastric cancer when compared to patients without. With that in mind, this minireview approaches, in an accessible way, the most important and current aspects about the role of NikS in the control of virulence factors of H. pylori and the potential clinical repercussions of this modulation.
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Affiliation(s)
- Fabrício Freire de Melo
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Hanna Santos Marques
- Campus Vitória da Conquista, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista 45083-900, Brazil
| | - Fabian Fellipe Bueno Lemos
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Marcel Silva Luz
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Samuel Luca Rocha Pinheiro
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Lorena Sousa de Carvalho
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Cláudio Lima Souza
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
| | - Márcio Vasconcelos Oliveira
- Institution Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Brazil
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Harvey ML, Lin AS, Sun L, Koyama T, Shuman JHB, Loh JT, Algood HMS, Scholz MB, McClain MS, Cover TL. Enhanced Fitness of a Helicobacter pylori babA Mutant in a Murine Model. Infect Immun 2021; 89:e0072520. [PMID: 34310886 PMCID: PMC8445181 DOI: 10.1128/iai.00725-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 07/05/2021] [Indexed: 11/20/2022] Open
Abstract
Helicobacter pylori genomes encode over 60 predicted outer membrane proteins (OMPs). Several OMPs in the Hop family act as adhesins, but the functions of most Hop proteins are unknown. To identify hop mutant strains exhibiting differential fitness in vivo compared to in vitro, we used a genetic barcoding method that allowed us to track changes in the proportional abundance of H. pylori strains within a mixed population. We generated a library of hop mutant strains, each containing a unique nucleotide barcode, as well as a library of control strains, each containing a nucleotide barcode in an intergenic region predicted to be a neutral locus unrelated to bacterial fitness. We orogastrically inoculated each of the libraries into mice and analyzed compositional changes in the populations over time in vivo compared to changes detected in the populations during library passage in vitro. The control library proliferated as a relatively stable community in vitro, but there was a reduction in the population diversity of this library in vivo and marked variation in the dominant strains recovered from individual animals, consistent with the existence of a nonselective bottleneck in vivo. We did not identify any OMP mutants exhibiting fitness defects exclusively in vivo without corresponding fitness defects in vitro. Conversely, a babA mutant exhibited a strong fitness advantage in vivo but not in vitro. These findings, when taken together with results of other studies, suggest that production of BabA may have differential effects on H. pylori fitness depending on the environmental conditions.
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Affiliation(s)
- M. Lorena Harvey
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Aung Soe Lin
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Lili Sun
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Tatsuki Koyama
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jennifer H. B. Shuman
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - John T. Loh
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Holly M. Scott Algood
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Matthew B. Scholz
- Vanderbilt Technologies for Advanced Genetics (VANTAGE), Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Mark S. McClain
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Timothy L. Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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Small RNA mediated gradual control of lipopolysaccharide biosynthesis affects antibiotic resistance in Helicobacter pylori. Nat Commun 2021; 12:4433. [PMID: 34290242 PMCID: PMC8295292 DOI: 10.1038/s41467-021-24689-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
The small, regulatory RNA RepG (Regulator of polymeric G-repeats) regulates the expression of the chemotaxis receptor TlpB in Helicobacter pylori by targeting a variable G-repeat in the tlpB mRNA leader. Here, we show that RepG additionally controls lipopolysaccharide (LPS) phase variation by also modulating the expression of a gene (hp0102) that is co-transcribed with tlpB. The hp0102 gene encodes a glycosyltransferase required for LPS O-chain biosynthesis and in vivo colonization of the mouse stomach. The G-repeat length defines a gradual (rather than ON/OFF) control of LPS biosynthesis by RepG, and leads to gradual resistance to a membrane-targeting antibiotic. Thus, RepG-mediated modulation of LPS structure might impact host immune recognition and antibiotic sensitivity, thereby helping H. pylori to adapt and persist in the host. The small RNA RepG modulates expression of chemotaxis receptor TlpB in Helicobacter pylori by targeting a length-variable G-repeat in the tlpB mRNA. Here, Pernitzsch et al. show that RepG also gradually controls lipopolysaccharide biosynthesis, antibiotic susceptibility, and in-vivo colonization of the stomach, by regulating a gene that is co-transcribed with tlpB.
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Network topology analysis of essential genes interactome of Helicobacter pylori to explore novel therapeutic targets. Microb Pathog 2021; 158:105059. [PMID: 34157412 DOI: 10.1016/j.micpath.2021.105059] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/09/2021] [Accepted: 06/14/2021] [Indexed: 11/24/2022]
Abstract
The Helicobacter pylori chronic colonization produces a wide range of gastric diseases in the gastric mucosa by abetting inflammation. Amidst coevolution and reorganization of its metabolism with humans, it has become difficult still imperative to understand and prevent its growth. This study focus to explore functional insights into identification of hub proteins/genes by aggregating the behavior of genes connected in a protein-protein interaction (PPI) network. We have constructed a PPI network of 123 essential genes along with 1213 interactions in H. pylori 26695. The degree and other centrality measures analysis assist in identifying the important hub nodes, which are top-ranked proteins. A total of nine proteins (recA, guaA, dnaK, rpsB, rplQ, rpmA, rpmC, rpmF, and rpsE) were obtained with high degree (k), betweenness centrality (BC) value. Gene ontology analysis reveals 8, 5 and 3 GO terms correspond to biological processes, cellular components and molecular function respectively. Gene complexes of hypothetical proteins (HPs) were related to aminoacyl-tRNA biosynthesis, biosynthesis of secondary metabolites, bacterial secretion system and protein export. The MCODE analysis revealed that protein from module M1, M3 and M6 include the proteins which have highest degree and BC values. It is noteworthy to mention that the bifunctional GMP synthase/glutamine amidotransferase protein (guaA), molecular chaperon (dnaK), recombinase A (recA) constitute as hub proteins. As a result, these genes are considered as network hub nodes that might be used as therapeutic targets. Our analysis affords a detailed understanding of the molecular process and pathways regulated by the essential genes in H. pylori 26695.
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Xie W, Zhao W, Zou Z, Kong L, Yang L. Oral multivalent epitope vaccine, based on UreB, HpaA, CAT, and LTB, for prevention and treatment of Helicobacter pylori infection in C57BL / 6 mice. Helicobacter 2021; 26:e12807. [PMID: 33847026 DOI: 10.1111/hel.12807] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/19/2021] [Accepted: 03/26/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND As the resistance of Helicobacter pylori to traditional triple therapy is gradually revealed, an increasing number of people are focusing on vaccine treatments for H. pylori infection. Epitope vaccines are a promising strategy for the treatment of H. pylori infection, and multivalent vaccines will be more effective than monovalent vaccines. MATERIALS AND METHODS In this study, we designed a multivalent vaccine named LHUC, which consists of the adjuvant LTB as well as three Th cell epitopes (HpaA154-171 , UreB237-251, and UreB546-561 ) and five B-cell epitopes (UreB349-363 , UreB327-334 , CAT394-405 , CAT387-397, and HpaA132-141 ) from UreB, HpaA, and catalase. In BALB/c mice, the specificity and immunogenicity of the fusion peptide LHUC and the neutralization of H. pylori urease and catalase by the specific IgG elicited by LHUC were evaluated. The preventive and therapeutic effects of LHUC were evaluated in C57BL/6 mice infected with H. pylori. RESULTS The results showed that compared with LTB and PBS, LHUC induced specific IgG and IgA antibody production in mice, and IgG antibodies significantly inhibited the H. pylori urease and catalase activities in vitro. Additionally, by detecting the levels of IFN-γ, IL-4, and IL-17 in lymphocyte supernatants, we proved that LHUC could activate Th1, Th2, and Th17 mixed T-cell immune responses in vivo. Finally, a C57BL/6 mouse model of gastric infection with H. pylori was established. The results showed that compared with the effects of LTB and PBS, the prevention and treatment effects of oral inoculation with LHUC significantly inhibited bacterial colonization. CONCLUSIONS In conclusion, LHUC, a multivalent vaccine based on multiple H. pylori antigens, is a promising and safe vaccine that can effectively reduce the colonization of H. pylori in the stomach.
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Affiliation(s)
- Wenwei Xie
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
| | - Wenfeng Zhao
- Department of Biochemistry, China Pharmaceutical university, Nanjing, China
| | - Ziling Zou
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
| | - Lingyi Kong
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
| | - Lei Yang
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
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9
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Jia J, Zhang C, Liu Y, Huang Y, Bai Y, Hang X, Zeng L, Zhu D, Bi H. Armeniaspirol A: a novel anti-Helicobacter pylori agent. Microb Biotechnol 2021; 15:442-454. [PMID: 33780131 PMCID: PMC8867979 DOI: 10.1111/1751-7915.13807] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/11/2021] [Indexed: 12/25/2022] Open
Abstract
Antibiotic resistance in Helicobacter pylori has been growing worldwide with current treatment regimens. Development of new compounds for treatment of H. pylori infections is urgently required to achieve a successful eradication therapy in the future. Armeniaspirols, a novel class of natural products isolated from Streptomyces armeniacus, have been previously identified as antibacterial agents against Gram‐positive pathogens. In this study, we found that armeniaspirol A (ARM1) exhibited potent antibacterial activity against H. pylori, including multidrug‐resistant strains, with MIC range values of 4–16 μg ml‐1. The underlying mechanism of action of ARM1 against H. pylori involved the disruption of bacterial cell membranes. Also, ARM1 inhibited biofilm formation, eliminated preformed biofilms and killed biofilm‐encased H. pylori in a dose‐dependent manner. In a mouse model of multidrug‐resistant H. pylori infection, dual therapy with ARM1 and omeprazole showed efficient in vivo killing efficacy comparable to the standard triple therapy, and induced negligible toxicity against normal tissues. Moreover, at acidic pH 2.5, ARM1 exhibited a much more potent anti‐H. pylori activity than metronidazole. Thus, these findings demonstrated that ARM1 is a novel potent anti‐H. pylori agent, which can be developed as a promising drug lead for treatment of H. pylori infections.
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Affiliation(s)
- Jia Jia
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China.,Department of Gastroenterology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Chongwen Zhang
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Yaqi Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, 430071, China
| | - Yanqiang Huang
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Yuefan Bai
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Xudong Hang
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Liping Zeng
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Dongqing Zhu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, 430071, China
| | - Hongkai Bi
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology & Helicobacter pylori Research Centre, Nanjing Medical University, Nanjing, Jiangsu, 211166, China.,Department of Gastroenterology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
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10
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Dihydrotanshinone I Is Effective against Drug-Resistant Helicobacter pylori In Vitro and In Vivo. Antimicrob Agents Chemother 2021; 65:AAC.01921-20. [PMID: 33318002 DOI: 10.1128/aac.01921-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/05/2020] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a major global pathogen and has been implicated in gastritis, peptic ulcer, and gastric carcinoma. The efficacy of the extensive therapy of H. pylori infection with antibiotics is compromised by the development of drug resistance and toxicity toward human gut microbiota, which urgently demands novel and selective antibacterial strategies. The present study was mainly performed to assess the in vitro and in vivo effects of a natural herbal compound, dihydrotanshinone I (DHT), against standard and clinical H. pylori strains. DHT demonstrated effective antibacterial activity against H. pylori in vitro (MIC50/90, 0.25/0.5 μg/ml), with no development of resistance during continuous serial passaging. Time-kill curves showed strong time-dependent bactericidal activity for DHT. Also, DHT eliminated preformed biofilms and killed biofilm-encased H. pylori cells more efficiently than the conventional antibiotic metronidazole. In mouse models of multidrug-resistant H. pylori infection, dual therapy with DHT and omeprazole showed in vivo killing efficacy superior to that of the standard triple-therapy approach. Moreover, DHT treatment induces negligible toxicity against normal tissues and exhibits a relatively good safety index. These results suggest that DHT could be suitable for use as an anti-H. pylori agent in combination with a proton pump inhibitor to eradicate multidrug-resistant H. pylori.
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11
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Antibiotic Resistance Results of Helicobacter pylori in a University Hospital: Comparison of the Hybridization Test and Real-Time Polymerase Chain Reaction. Int J Microbiol 2021; 2020:8853298. [PMID: 33488727 PMCID: PMC7803162 DOI: 10.1155/2020/8853298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/22/2020] [Accepted: 10/23/2020] [Indexed: 01/10/2023] Open
Abstract
Aim H. pylori is a bacterial pathogen in the human stomach which infects about 50% of the world population. Untreated infection can lead to various diseases leading to cancer. Some of the H. pylori strains are asymptomatic, but some of them cause more severe diseases. Standard treatment protocol used for the treatment of H. pylori infection is triple therapy, which includes omeprazole as a proton pump inhibitor (PPI) and two antibiotics usually consist of amoxicillin and clarithromycin or metronidazole. In the recent years, because of the increase in the rate of antibiotic resistance, the eradication rate has decreased. Materials and Methods We evaluated 140 patients who applied to a university hospital gastroenterology department and underwent biopsy during endoscopy. In these patients, we analysed floroquinolone and clarithromycin resistance using the GenoType® HelicoDR (Hain Life Science, Germany). We also used the real-time method for clarithromycin resistance. Results We found the number and rate of floroquinolone resistance as 20 (25.6%) and clarithromycine resistance as 31 (39.7%). With the real-time PCR method, we detected clarithromycine resistance in 26 (33.3%) patients. These results were not statistically significant. Discussion and Conclusion. Our results show similarity to the other studies held in our country. There should be more studies for the policy of eradication through our country.
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12
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Dey TK, Karmakar BC, Sarkar A, Paul S, Mukhopadhyay AK. A Mouse Model of Helicobacter pylori Infection. Methods Mol Biol 2021; 2283:131-151. [PMID: 33765316 DOI: 10.1007/978-1-0716-1302-3_14] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Infection with Helicobacter pylori (H. pylori) is of great distress because of its vital role in the pathogenesis of chronic gastritis, peptic ulcers, and in the multi-step carcinogenic process of gastric cancer. The increasing antibiotic resistance pattern of H. pylori worldwide has prompted the World Health Organization to put this organism in the priority pathogens list. To study the disease biology, evaluation of drugs, treatment outcome and to come up with probable vaccination strategies, competent animal models that reproduce the signature of human infection are essential. Initial reports about animal colonization with H. pylori have shown significant heterogeneity, to such an extent that Barry Marshall, Nobel laureate for the discovery of H. pylori , infected himself with the bacterium to show its involvement in acute gastric illness. A paradigm-shift discovery of the H. pylori mouse-adapted strain SS1 has opened the avenues of research regarding the organism and its pathogenicity. Although the mouse model of H. pylori infection is being utilized all over the world, there are certain issues that need awareness and specific information to achieve successful, consistent colonization with symptoms resembling human. This chapter details an established and reliable protocol for the development of a competent mouse model for H. pylori infection leading to various gastro-intestinal diseases.
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Affiliation(s)
- Tanmoy Kumar Dey
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Bipul Chandra Karmakar
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Avijit Sarkar
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sangita Paul
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish Kumar Mukhopadhyay
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India.
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13
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Moulton KD, Adewale AP, Carol HA, Mikami SA, Dube DH. Metabolic Glycan Labeling-Based Screen to Identify Bacterial Glycosylation Genes. ACS Infect Dis 2020; 6:3247-3259. [PMID: 33186014 PMCID: PMC7808405 DOI: 10.1021/acsinfecdis.0c00612] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Bacterial cell surface glycans are quintessential drug targets due to their critical role in colonization of the host, pathogen survival, and immune evasion. The dense cell envelope glycocalyx contains distinctive monosaccharides that are stitched together into higher order glycans to yield exclusively bacterial structures that are critical for strain fitness and pathogenesis. However, the systematic study and inhibition of bacterial glycosylation enzymes remains challenging. Bacteria produce glycans containing rare sugars refractory to traditional glycan analysis, complicating the study of bacterial glycans and the identification of their biosynthesis machinery. To ease the study of bacterial glycans in the absence of detailed structural information, we used metabolic glycan labeling to detect changes in glycan biosynthesis. Here, we screened wild-type versus mutant strains of the gastric pathogen Helicobacter pylori, ultimately permitting the identification of genes involved in glycoprotein and lipopolysaccharide biosynthesis. Our findings provide the first evidence that H. pylori protein glycosylation proceeds via a lipid carrier-mediated pathway that overlaps with lipopolysaccharide biosynthesis. Protein glycosylation mutants displayed fitness defects consistent with those induced by small molecule glycosylation inhibitors. Broadly, our results suggest a facile approach to screen for bacterial glycosylation genes and gain insight into their biosynthesis and functional importance, even in the absence of glycan structural information.
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Affiliation(s)
- Karen D. Moulton
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
| | - Adedunmola P. Adewale
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
| | - Hallie A. Carol
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
| | - Sage A. Mikami
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
| | - Danielle H. Dube
- Department of Chemistry & Biochemistry, Bowdoin College, 6600 College Station, Brunswick, ME 04011, USA
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14
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Jackson LK, Potter B, Schneider S, Fitzgibbon M, Blair K, Farah H, Krishna U, Bedford T, Peek RM, Salama NR. Helicobacter pylori diversification during chronic infection within a single host generates sub-populations with distinct phenotypes. PLoS Pathog 2020; 16:e1008686. [PMID: 33370399 PMCID: PMC7794030 DOI: 10.1371/journal.ppat.1008686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 01/08/2021] [Accepted: 10/22/2020] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori chronically infects the stomach of approximately half of the world's population. Manifestation of clinical diseases associated with H. pylori infection, including cancer, is driven by strain properties and host responses; and as chronic infection persists, both are subject to change. Previous studies have documented frequent and extensive within-host bacterial genetic variation. To define how within-host diversity contributes to phenotypes related to H. pylori pathogenesis, this project leverages a collection of 39 clinical isolates acquired prospectively from a single subject at two time points and from multiple gastric sites. During the six years separating collection of these isolates, this individual, initially harboring a duodenal ulcer, progressed to gastric atrophy and concomitant loss of acid secretion. Whole genome sequence analysis identified 1,767 unique single nucleotide polymorphisms (SNPs) across isolates and a nucleotide substitution rate of 1.3x10-4 substitutions/site/year. Gene ontology analysis identified cell envelope genes among the genes with excess accumulation of nonsynonymous SNPs (nSNPs). A maximum likelihood tree based on genetic similarity clusters isolates from each time point separately. Within time points, there is segregation of subgroups with phenotypic differences in bacterial morphology, ability to induce inflammatory cytokines, and mouse colonization. Higher inflammatory cytokine induction in recent isolates maps to shared polymorphisms in the Cag PAI protein, CagY, while rod morphology in a subgroup of recent isolates mapped to eight mutations in three distinct helical cell shape determining (csd) genes. The presence of subgroups with unique genetic and phenotypic properties suggest complex selective forces and multiple niches within the stomach during chronic infection.
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Affiliation(s)
- Laura K. Jackson
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, United States of America
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Barney Potter
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Sean Schneider
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Matthew Fitzgibbon
- Genomics & Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Kris Blair
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, United States of America
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Hajirah Farah
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
| | - Uma Krishna
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Trevor Bedford
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Richard M. Peek
- Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Nina R. Salama
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, United States of America
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
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15
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Genetic requirements and transcriptomics of Helicobacter pylori biofilm formation on abiotic and biotic surfaces. NPJ Biofilms Microbiomes 2020; 6:56. [PMID: 33247117 PMCID: PMC7695850 DOI: 10.1038/s41522-020-00167-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/30/2020] [Indexed: 12/16/2022] Open
Abstract
Biofilm growth is a widespread mechanism that protects bacteria against harsh environments, antimicrobials, and immune responses. These types of conditions challenge chronic colonizers such as Helicobacter pylori but it is not fully understood how H. pylori biofilm growth is defined and its impact on H. pylori survival. To provide insights into H. pylori biofilm growth properties, we characterized biofilm formation on abiotic and biotic surfaces, identified genes required for biofilm formation, and defined the biofilm-associated gene expression of the laboratory model H. pylori strain G27. We report that H. pylori G27 forms biofilms with a high biomass and complex flagella-filled 3D structures on both plastic and gastric epithelial cells. Using a screen for biofilm-defective mutants and transcriptomics, we discovered that biofilm cells demonstrated lower transcripts for TCA cycle enzymes but higher ones for flagellar formation, two type four secretion systems, hydrogenase, and acetone metabolism. We confirmed that biofilm formation requires flagella, hydrogenase, and acetone metabolism on both abiotic and biotic surfaces. Altogether, these data suggest that H. pylori is capable of adjusting its phenotype when grown as biofilm, changing its metabolism, and re-shaping flagella, typically locomotion organelles, into adhesive structures.
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16
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Eisenbart SK, Alzheimer M, Pernitzsch SR, Dietrich S, Stahl S, Sharma CM. A Repeat-Associated Small RNA Controls the Major Virulence Factors of Helicobacter pylori. Mol Cell 2020; 80:210-226.e7. [PMID: 33002424 DOI: 10.1016/j.molcel.2020.09.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/29/2020] [Accepted: 09/04/2020] [Indexed: 12/12/2022]
Abstract
Many bacterial pathogens regulate their virulence genes via phase variation, whereby length-variable simple sequence repeats control the transcription or coding potential of those genes. Here, we have exploited this relationship between DNA structure and physiological function to discover a globally acting small RNA (sRNA) regulator of virulence in the gastric pathogen Helicobacter pylori. Our study reports the first sRNA whose expression is affected by a variable thymine (T) stretch in its promoter. We show the sRNA post-transcriptionally represses multiple major pathogenicity factors of H. pylori, including CagA and VacA, by base pairing to their mRNAs. We further demonstrate transcription of the sRNA is regulated by the nickel-responsive transcriptional regulator NikR (thus named NikS for nickel-regulated sRNA), thereby linking virulence factor regulation to nickel concentrations. Using in-vitro infection experiments, we demonstrate NikS affects host cell internalization and epithelial barrier disruption. Together, our results show NikS is a phase-variable, post-transcriptional global regulator of virulence properties in H. pylori.
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Affiliation(s)
- Sara K Eisenbart
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Mona Alzheimer
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Sandy R Pernitzsch
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Sascha Dietrich
- Core Unit Systems Medicine, Interdisciplinary Center for Clinical Research (IZKF) of the University Hospital Würzburg, 97080 Würzburg, Germany
| | - Stephanie Stahl
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Cynthia M Sharma
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany.
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17
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Hathroubi S, Zerebinski J, Clarke A, Ottemann KM. Helicobacter pylori Biofilm Confers Antibiotic Tolerance in Part via A Protein-Dependent Mechanism. Antibiotics (Basel) 2020; 9:E355. [PMID: 32599828 PMCID: PMC7345196 DOI: 10.3390/antibiotics9060355] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022] Open
Abstract
Helicobacter pylori, a WHO class I carcinogen, is one of the most successful human pathogens colonizing the stomach of over 4.4 billion of the world's population. Antibiotic therapy represents the best solution but poor response rates have hampered the elimination of H. pylori. A growing body of evidence suggests that H. pylori forms biofilms, but the role of this growth mode in infection remains elusive. Here, we demonstrate that H. pylori cells within a biofilm are tolerant to multiple antibiotics in a manner that depends partially on extracellular proteins. Biofilm-forming cells were tolerant to multiple antibiotics that target distinct pathways, including amoxicillin, clarithromycin, and tetracycline. Furthermore, this tolerance was significantly dampened following proteinase K treatment. These data suggest that H. pylori adapts its phenotype during biofilm growth resulting in decreased antibiotic susceptibility but this tolerance can be partially ameliorated by extracellular protease treatment.
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Affiliation(s)
- Skander Hathroubi
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA
- Institüt für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (J.Z.); (A.C.)
| | - Julia Zerebinski
- Institüt für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (J.Z.); (A.C.)
| | - Aaron Clarke
- Institüt für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (J.Z.); (A.C.)
| | - Karen M. Ottemann
- Institüt für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (J.Z.); (A.C.)
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18
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Salama NR. Cell morphology as a virulence determinant: lessons from Helicobacter pylori. Curr Opin Microbiol 2020; 54:11-17. [PMID: 32014717 PMCID: PMC7247928 DOI: 10.1016/j.mib.2019.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 12/30/2019] [Indexed: 02/06/2023]
Abstract
A genetic screen for colonization factors of the human stomach pathogen Helicobacter pylori took a surprising turn with the discovery that some colonization mutants had lost helical cell morphology. Further pursuit of direct morphology screens revealed a large H. pylori 'shapesome' complex consisting of peptidoglycan modification and precursor synthesis enzymes, a cytoskeletal element and putative scaffold or regulatory proteins that promote enhanced asymmetric cell wall growth. Functional characterization of H. pylori shape mutants indicates multiple roles for cell shape during colonization of mucosal surfaces. Conservation of both the molecular constituents of the H. pylori cell shape program and a newly appreciated enrichment of this morphotype at mucosal surface suggests that helical organisms may be particularly well poised to exploit host perturbations to become pathogens.
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Affiliation(s)
- Nina R Salama
- Human Biology Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N, Seattle, WA 98109, United States.
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19
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The Cyclopropane Fatty Acid Synthase Mediates Antibiotic Resistance and Gastric Colonization of Helicobacter pylori. J Bacteriol 2019; 201:JB.00374-19. [PMID: 31358615 DOI: 10.1128/jb.00374-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/24/2019] [Indexed: 01/08/2023] Open
Abstract
Cyclopropane fatty acids (CFAs) are synthetized by the addition of a methylene group from S-adenosyl-l-methionine across the carbon-carbon double bonds of unsaturated fatty acid chains of membrane phospholipids. This fatty acid cyclopropanation, catalyzed by the CFA synthase (CfaS) enzyme, occurs in many bacteria, including the human pathogen Helicobacter pylori Although the cyclopropane modification was reported to play a key role in the adaptation in response to environmental stress, its role in H. pylori remains unknown. In this study, we showed that H. pylori HP0416 encodes a functional CfaS. The enzyme was demonstrated to be required for acid resistance, antibiotic resistance, intracellular survival and mouse gastric colonization, and cell membrane integrity. Moreover, the tool compound dioctylamine, which acts as a substrate mimic, directly inhibits the CfaS function of H. pylori, resulting into sensitivity to acid stress, increased antibiotic susceptibility, and attenuated abilities to avoid macrophage killing and to colonize mouse stomachs. These results validate CfaS as a promising antibiotic target and provide new potentials for this recognized target in future anti-H. pylori drug discovery efforts.IMPORTANCE The increasing prevalence of multidrug-resistant Helicobacter pylori strains has created an urgent need for alternative therapeutic regimens that complement the current antibiotic treatment strategies for H. pylori eradication; however, this is greatly hampered due to a lack of "druggable" targets. Although the CFAs are present in H. pylori cytoplasmic membranes at high levels, their physiological role has not been established. In this report, deletion of the CFA synthase CfaS was shown to attenuate acid and drug resistance, immune escape, and gastric colonization of H. pylori These findings were validated by inhibition of the CfaS activity with the tool compound dioctylamine. These studies identify this enzyme as an attractive target for further drug discovery efforts against H. pylori.
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20
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Nonhelical Helicobacter pylori Mutants Show Altered Gland Colonization and Elicit Less Gastric Pathology than Helical Bacteria during Chronic Infection. Infect Immun 2019; 87:IAI.00904-18. [PMID: 31061142 DOI: 10.1128/iai.00904-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/26/2019] [Indexed: 12/13/2022] Open
Abstract
Half of all humans harbor Helicobacter pylori in their stomachs. Helical cell shape is thought to facilitate H. pylori's ability to bore into the protective mucus layer in a corkscrew-like motion, thereby enhancing colonization of the stomach. H. pylori cell shape mutants show impaired colonization of the mouse stomach, highlighting the importance of cell shape in infection. To gain a deeper understanding of how helical cell morphology promotes host colonization by H. pylori, we used three-dimensional confocal microscopy to visualize the clinical isolate PMSS1 and an isogenic straight-rod mutant (Δcsd6) within thick longitudinal mouse stomach sections. We also performed volumetric image analysis to quantify the number of bacteria residing within corpus and antral glands in addition to measuring total CFU. We found that straight rods show attenuation during acute colonization of the stomach (1 day or 1 week postinfection) as measured by total CFU. Our quantitative imaging revealed that wild-type bacteria extensively colonized antral glands at 1 week postinfection, while csd6 mutants showed variable colonization of the antrum at this time point. During chronic infection (1 or 3 months postinfection), total CFU were highly variable but similar for wild-type and straight rods. Both wild-type and straight rods persisted and expanded in corpus glands during chronic infection. However, the straight rods showed reduced inflammation and disease progression. Thus, helical cell shape contributes to tissue interactions that promote inflammation during chronic infection, in addition to facilitating niche acquisition during acute infection.
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21
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Huang Y, Hang X, Jiang X, Zeng L, Jia J, Xie Y, Li F, Bi H. In Vitro and In Vivo Activities of Zinc Linolenate, a Selective Antibacterial Agent against Helicobacter pylori. Antimicrob Agents Chemother 2019; 63:e00004-19. [PMID: 30936098 PMCID: PMC6535540 DOI: 10.1128/aac.00004-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 03/22/2019] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment for H. pylori infection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment of H. pylori infection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates of H. pyloriin vitro with no development of resistance during continuous serial passaging. The mechanisms of ZnLla action against H. pylori involved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistant H. pylori infection, ZnLla showed in vivo killing efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla for H. pylori provides an attractive candidate for novel targeted anti-H. pylori treatment.
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Affiliation(s)
- Yanqiang Huang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xudong Hang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xueqing Jiang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Liping Zeng
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jia Jia
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yong Xie
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Fei Li
- Department of Medicinal Chemistry, School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hongkai Bi
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China
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22
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Ailloud F, Didelot X, Woltemate S, Pfaffinger G, Overmann J, Bader RC, Schulz C, Malfertheiner P, Suerbaum S. Within-host evolution of Helicobacter pylori shaped by niche-specific adaptation, intragastric migrations and selective sweeps. Nat Commun 2019; 10:2273. [PMID: 31118420 PMCID: PMC6531487 DOI: 10.1038/s41467-019-10050-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/10/2019] [Indexed: 02/07/2023] Open
Abstract
The human pathogen Helicobacter pylori displays extensive genetic diversity. While H. pylori is known to evolve during infection, population dynamics inside the gastric environment have not been extensively investigated. Here we obtained gastric biopsies from multiple stomach regions of 16 H. pylori-infected adults, and analyze the genomes of 10 H. pylori isolates from each biopsy. Phylogenetic analyses suggest location-specific evolution and bacterial migration between gastric regions. Migration is significantly more frequent between the corpus and the fundus than with the antrum, suggesting that physiological differences between antral and oxyntic mucosa contribute to spatial partitioning of H. pylori populations. Associations between H. pylori gene polymorphisms and stomach niches suggest that chemotaxis, regulatory functions and outer membrane proteins contribute to specific adaptation to the antral and oxyntic mucosa. Moreover, we show that antibiotics can induce severe population bottlenecks and likely play a role in shaping the population structure of H. pylori.
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Affiliation(s)
- Florent Ailloud
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany
- DZIF German Center for Infection Research, Munich Site, Munich, Germany
- DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany
| | - Xavier Didelot
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
- Department of Statistics, University of Warwick, Coventry, CV4 7AL, UK
| | - Sabrina Woltemate
- Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany
| | - Gudrun Pfaffinger
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
| | - Jörg Overmann
- DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, 38124, Braunschweig, Germany
| | - Ruth Christiane Bader
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
- National Reference Center for Helicobacter pylori, Max von Pettenkofer Institute, 80336, Munich, Germany
| | - Christian Schulz
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, 39106, Magdeburg, Germany
- Department of Medicine 2, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Peter Malfertheiner
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, 39106, Magdeburg, Germany
- Department of Medicine 2, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Sebastian Suerbaum
- Department of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, 80336, Munich, Germany.
- Institute of Medical Microbiology and Hospital Epidemiology, MHH Hannover Medical School, 30625, Hannover, Germany.
- DZIF German Center for Infection Research, Munich Site, Munich, Germany.
- DZIF German Center for Infection Research, Hannover-Braunschweig Site, Hannover, Germany.
- National Reference Center for Helicobacter pylori, Max von Pettenkofer Institute, 80336, Munich, Germany.
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23
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Akeel M, Shehata A, Elhafey A, Elmakki E, Aboshouk T, Ageely H, Mahfouz M. Helicobacter pylori vacA, cagA and iceA genotypes in dyspeptic patients from southwestern region, Saudi Arabia: distribution and association with clinical outcomes and histopathological changes. BMC Gastroenterol 2019; 19:16. [PMID: 30683054 PMCID: PMC6346553 DOI: 10.1186/s12876-019-0934-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023] Open
Abstract
Background The aim of this study was to identify the common H. pylori virulence genes among dyspeptic Southwestern Saudi patients and their association with clinical outcomes and histopathological findings to help practitioners and researchers in the region for better management of infections caused by such bacteria. Methods Four hundred two gastric biopsy specimens were analyzed using histopathological examination and real time-PCR. The positive 187 specimens by RT-PCR were genotyped using PCR targeting cagA, vacA and iceA genes. Results One hundred twenty-eight gastric biopsy specimens were positive in genotyping PCRs. The cagA, vacA, iceA1 and iceA2 genes were detected in rates of 49.2% (63/128), 100%(128/128), 42.2% (54/128), 32.8% (42/128), respectively. The vacA s1as1bm2 subtype was the highest 23.4% (30/128), followed by m2 and s1a1b subtypes which were equally detected [16.4% (21/128) for each]. The iceA genes were significantly associated with gastritis and gastric ulcer. Overall, vacA genotypes were significantly associated with gastritis, gastric and duodenal ulcers. The vacA subtypes: s1as1bm2, s1a1b and s2 m2 showed chronic active gastritis in percentages of 90.0, 81, and 84.2%, respectively. All vacA mixed genotypes showed chronic active gastritis. Conclusions H. pylori virulence genes are highly prevalent and diverse among patients with dyspepsia in Southwestern region of Saudi Arabia. The iceA genes and the different vacA subtypes are significantly associated with the clinical outcomes and histopathological changes especially chronic active gastritis.
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Affiliation(s)
- Mohammed Akeel
- Department of Anatomy, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia.
| | - Atef Shehata
- Department of Microbiology and Immunology, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia.,Department of Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Ahmed Elhafey
- Department of Pathology, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia.,Department of Pathology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Erwa Elmakki
- Department of Internal Medicine, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Thanaa Aboshouk
- Department of Biochemistry, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Hussein Ageely
- Department of Internal Medicine, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Mohammed Mahfouz
- Department of Family and Community Medicine, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia
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24
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Abstract
Bacterial regulatory RNAs are key players in adaptation to changing environmental conditions and response to diverse cellular stresses. However, while regulatory RNAs of bacterial pathogens have been intensely studied under defined conditions in vitro, characterization of their role during the infection of eukaryotic host organisms is lagging behind. This review summarizes our current understanding of the contribution of the different classes of regulatory RNAs and RNA-binding proteins to bacterial virulence and illustrates their role in infection by reviewing the mechanisms of some prominent representatives of each class. Emerging technologies are described that bear great potential for global, unbiased studies of virulence-related RNAs in bacterial model and nonmodel pathogens in the future. The review concludes by deducing common principles of RNA-mediated gene expression control of virulence programs in different pathogens, and by defining important open questions for upcoming research in the field.
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25
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Mannion A, Shen Z, Fox JG. Comparative genomics analysis to differentiate metabolic and virulence gene potential in gastric versus enterohepatic Helicobacter species. BMC Genomics 2018; 19:830. [PMID: 30458713 PMCID: PMC6247508 DOI: 10.1186/s12864-018-5171-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/15/2018] [Indexed: 02/08/2023] Open
Abstract
Background The genus Helicobacter are gram-negative, microaerobic, flagellated, mucus-inhabiting bacteria associated with gastrointestinal inflammation and classified as gastric or enterohepatic Helicobacter species (EHS) according to host species and colonization niche. While there are over 30 official species, little is known about the physiology and pathogenic mechanisms of EHS, which account for most in the genus, as well as what genetic factors differentiate gastric versus EHS, given they inhabit different hosts and colonization niches. The objective of this study was to perform a whole-genus comparative analysis of over 100 gastric versus EHS genomes in order to identify genetic determinants that distinguish these Helicobacter species and provide insights about their evolution/adaptation to different hosts, colonization niches, and mechanisms of virulence. Results Whole-genome phylogeny organized Helicobacter species according to their presumed gastric or EHS classification. Analysis of orthologs revealed substantial heterogeneity in physiological and virulence-related genes between gastric and EHS genomes. Metabolic reconstruction predicted that unlike gastric species, EHS appear asaccharolytic and dependent on amino/organic acids to fuel metabolism. Additionally, gastric species lack de novo biosynthetic pathways for several amino acids and purines found in EHS and instead rely on environmental uptake/salvage pathways. Comparison of virulence factor genes between gastric and EHS genomes identified overlapping yet distinct profiles and included canonical cytotoxins, outer membrane proteins, secretion systems, and survival factors. Conclusions The major differences in predicted metabolic function suggest gastric species and EHS may have evolved for survival in the nutrient-rich stomach versus the nutrient-devoid environments, respectively. Contrasting virulence factor gene profiles indicate gastric species and EHS may utilize different pathogenic mechanisms to chronically infect hosts and cause inflammation and tissue damage. The findings from this study provide new insights into the genetic differences underlying gastric versus EHS and support the need for future experimental studies to characterize these pathogens. Electronic supplementary material The online version of this article (10.1186/s12864-018-5171-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anthony Mannion
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Zeli Shen
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA
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26
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Pasala C, Chilamakuri CSR, Katari SK, Nalamolu RM, Bitla AR, Umamaheswari A. An in silico study: Novel targets for potential drug and vaccine design against drug resistant H. pylori. Microb Pathog 2018; 122:156-161. [DOI: 10.1016/j.micpath.2018.05.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 05/19/2018] [Accepted: 05/22/2018] [Indexed: 02/08/2023]
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27
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Yuan XY, Wang Y, Wang MY. The type IV secretion system in Helicobacter pylori. Future Microbiol 2018; 13:1041-1054. [PMID: 29927340 DOI: 10.2217/fmb-2018-0038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori (H. pylori) has an essential role in the pathogenesis of gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma and gastric cancer. The severity of the host inflammatory responses against the bacteria have been straightly associated with a special bacterial virulence factor, the cag pathogenicity island, which is a type IV secretion system (T4SS) to deliver CagA into the host cells. Besides cag-T4SS, the chromosomes of H. pylori can encode another three T4SSs, including comB, tfs3 and tfs4. In this review, we systematically reviewed the four T4SSs of H. pylori and explored their roles in the pathogenesis of gastroduodenal diseases. The information summarized in this review might provide valuable insights into the pathogenic mechanism for H. pylori.
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Affiliation(s)
- Xiao-Yan Yuan
- Department of Central Lab, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, Shandong, 264200, PR China
| | - Ying Wang
- Department of Central Lab, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, Shandong, 264200, PR China
| | - Ming-Yi Wang
- Department of Central Lab, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, Shandong, 264200, PR China
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28
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Houston S, Lithgow KV, Osbak KK, Kenyon CR, Cameron CE. Functional insights from proteome-wide structural modeling of Treponema pallidum subspecies pallidum, the causative agent of syphilis. BMC STRUCTURAL BIOLOGY 2018; 18:7. [PMID: 29769048 PMCID: PMC5956850 DOI: 10.1186/s12900-018-0086-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/27/2018] [Indexed: 12/21/2022]
Abstract
Background Syphilis continues to be a major global health threat with 11 million new infections each year, and a global burden of 36 million cases. The causative agent of syphilis, Treponema pallidum subspecies pallidum, is a highly virulent bacterium, however the molecular mechanisms underlying T. pallidum pathogenesis remain to be definitively identified. This is due to the fact that T. pallidum is currently uncultivatable, inherently fragile and thus difficult to work with, and phylogenetically distinct with no conventional virulence factor homologs found in other pathogens. In fact, approximately 30% of its predicted protein-coding genes have no known orthologs or assigned functions. Here we employed a structural bioinformatics approach using Phyre2-based tertiary structure modeling to improve our understanding of T. pallidum protein function on a proteome-wide scale. Results Phyre2-based tertiary structure modeling generated high-confidence predictions for 80% of the T. pallidum proteome (780/978 predicted proteins). Tertiary structure modeling also inferred the same function as primary structure-based annotations from genome sequencing pipelines for 525/605 proteins (87%), which represents 54% (525/978) of all T. pallidum proteins. Of the 175 T. pallidum proteins modeled with high confidence that were not assigned functions in the previously annotated published proteome, 167 (95%) were able to be assigned predicted functions. Twenty-one of the 175 hypothetical proteins modeled with high confidence were also predicted to exhibit significant structural similarity with proteins experimentally confirmed to be required for virulence in other pathogens. Conclusions Phyre2-based structural modeling is a powerful bioinformatics tool that has provided insight into the potential structure and function of the majority of T. pallidum proteins and helped validate the primary structure-based annotation of more than 50% of all T. pallidum proteins with high confidence. This work represents the first T. pallidum proteome-wide structural modeling study and is one of few studies to apply this approach for the functional annotation of a whole proteome. Electronic supplementary material The online version of this article (10.1186/s12900-018-0086-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen Vivien Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | | | - Chris Richard Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
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29
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Wuchty S, Müller SA, Caufield JH, Häuser R, Aloy P, Kalkhof S, Uetz P. Proteome Data Improves Protein Function Prediction in the Interactome of Helicobacter pylori. Mol Cell Proteomics 2018; 17:961-973. [PMID: 29414760 DOI: 10.1074/mcp.ra117.000474] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/25/2018] [Indexed: 01/17/2023] Open
Abstract
Helicobacter pylori is a common pathogen that is estimated to infect half of the human population, causing several diseases such as duodenal ulcer. Despite one of the first pathogens to be sequenced, its proteome remains poorly characterized as about one-third of its proteins have no functional annotation. Here, we integrate and analyze known protein interactions with proteomic and genomic data from different sources. We find that proteins with similar abundances tend to interact. Such an observation is accompanied by a trend of interactions to appear between proteins of similar functions, although some show marked cross-talk to others. Protein function prediction with protein interactions is significantly improved when interactions from other bacteria are included in our network, allowing us to obtain putative functions of more than 300 poorly or previously uncharacterized proteins. Proteins that are critical for the topological controllability of the underlying network are significantly enriched with genes that are up-regulated in the spiral compared with the coccoid form of H. pylori Determining their evolutionary conservation, we present evidence that 80 protein complexes are identical in composition with their counterparts in Escherichia coli, while 85 are partially conserved and 120 complexes are completely absent. Furthermore, we determine network clusters that coincide with related functions, gene essentiality, genetic context, cellular localization, and gene expression in different cellular states.
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Affiliation(s)
- Stefan Wuchty
- From the ‡Dept. of Computer Science.,§Center for Computational Science.,¶Dept. of Biology.,‖Sylvester Comprehensive Cancer Center, Univ. of Miami, Miami, FL 33156
| | - Stefan A Müller
- **German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - J Harry Caufield
- ‡‡Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VI 23284
| | - Roman Häuser
- §§German Cancer Research Center, 69120 Heidelberg, Germany
| | - Patrick Aloy
- ¶¶Joint IRB-BSC-CRG Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona) and the Barcelona Institute of Science and Technology. Barcelona, Catalonia, Spain.,‖‖Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
| | - Stefan Kalkhof
- Department of Molecular Systems Biology, UFZ, Helmholtz-Centre for Environmental Research Leipzig, 04318 Leipzig, Germany.,Institute of Bioanalysis, University of Applied Sciences and Arts of Coburg, Friedrich-Streib-Str. 2, 96450 Coburg, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Department of Therapy Validation, 04103 Leipzig, Germany
| | - Peter Uetz
- ‡‡Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VI 23284
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30
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Li N, Cao M, Yi S, Cheng J, Wang L, Tao Y, Wu D, Peng J, Zhang M, Qi P, Zhao J. Effects of the RNA-binding protein, KSRP, on innate immune response against Helicobacter pylori infection in mice. Biochem Biophys Res Commun 2017; 495:1573-1579. [PMID: 29222050 DOI: 10.1016/j.bbrc.2017.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/04/2017] [Indexed: 11/29/2022]
Abstract
Helicobacter pylori (H. pylori) contributes to various gastric diseases such as chronic gastritis, gastric ulcer, and gastric carcinoma. Host innate immune response against the pathogen plays a significant role in elimination of pathogen infection. Importantly, pathogen elimination is closely related to numerous inflammatory-related genes that participate in complex biological response of cells to harmful stimuli. Here we studied effects of the KH-type splicing regulatory protein (KSRP), a RNA-binding protein, on innate immune response against H. pylori infection. We found that H. pylori infection downregulated KSRP expression directly, and that KSRP overexpression repressed upregulation of CXCL-2 expression induced by H. pylori and facilitated H. pylori proliferation in vitro. Similarly, KSRP overexpression in H. pylori mice also facilitated H. pylori proliferation and colonization, and induced more severe gastric mucosal damage. Intriguingly, CXCL-2 and HMOX-1 were upregulated in H. pylori infected mice after KSRP overexpression. This difference in expression of these genes implicated that KSRP was closely associated with and directly participated in the innate immune response against H. pylori. These results were beneficial for understanding the in vivo function of KSRP on innate immune response against pathogen infection.
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Affiliation(s)
- Ningzhe Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Mei Cao
- Core Laboratory, School of Medicine, Sichuan Provincial People's Hospital Affiliated to University of Electronic Science and Technology of China, Chengdu 610072, PR China
| | - Sijun Yi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Juan Cheng
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Lei Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Yuwei Tao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Daoyan Wu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Jingshan Peng
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Mao Zhang
- Core Laboratory, School of Medicine, Sichuan Provincial People's Hospital Affiliated to University of Electronic Science and Technology of China, Chengdu 610072, PR China
| | - Panpan Qi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China
| | - Jian Zhao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, PR China.
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31
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Machuca MA, Johnson KS, Liu YC, Steer DL, Ottemann KM, Roujeinikova A. Helicobacter pylori chemoreceptor TlpC mediates chemotaxis to lactate. Sci Rep 2017; 7:14089. [PMID: 29075010 PMCID: PMC5658362 DOI: 10.1038/s41598-017-14372-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/06/2017] [Indexed: 12/13/2022] Open
Abstract
It is recently appreciated that many bacterial chemoreceptors have ligand-binding domains (LBD) of the dCACHE family, a structure with two PAS-like subdomains, one membrane-proximal and the other membrane-distal. Previous studies had implicated only the membrane-distal subdomain in ligand recognition. Here, we report the 2.2 Å resolution crystal structure of dCACHE LBD of the Helicobacter pylori chemoreceptor TlpC. H. pylori tlpC mutants are outcompeted by wild type during stomach colonisation, but no ligands had been mapped to this receptor. The TlpC dCACHE LBD has two PAS-like subdomains, as predicted. The membrane-distal one possesses a long groove instead of a small, well-defined pocket. The membrane-proximal subdomain, in contrast, had a well-delineated pocket with a small molecule that we identified as lactate. We confirmed that amino acid residues making contact with the ligand in the crystal structure-N213, I218 and Y285 and Y249-were required for lactate binding. We determined that lactate is an H. pylori chemoattractant that is sensed via TlpC with a K D = 155 µM. Lactate is utilised by H. pylori, and our work suggests that this pathogen seeks out lactate using chemotaxis. Furthermore, our work suggests that dCACHE domain proteins can utilise both subdomains for ligand recognition.
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Affiliation(s)
- Mayra A Machuca
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Kevin S Johnson
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Yu C Liu
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - David L Steer
- Monash Biomedical Proteomics Facility, Monash University, Clayton, Victoria, 3800, Australia
| | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA.
| | - Anna Roujeinikova
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.
- Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia.
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32
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Thorell K, Yahara K, Berthenet E, Lawson DJ, Mikhail J, Kato I, Mendez A, Rizzato C, Bravo MM, Suzuki R, Yamaoka Y, Torres J, Sheppard SK, Falush D. Rapid evolution of distinct Helicobacter pylori subpopulations in the Americas. PLoS Genet 2017; 13:e1006546. [PMID: 28231283 PMCID: PMC5322909 DOI: 10.1371/journal.pgen.1006546] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/19/2016] [Indexed: 12/13/2022] Open
Abstract
For the last 500 years, the Americas have been a melting pot both for genetically diverse humans and for the pathogenic and commensal organisms associated with them. One such organism is the stomach-dwelling bacterium Helicobacter pylori, which is highly prevalent in Latin America where it is a major current public health challenge because of its strong association with gastric cancer. By analyzing the genome sequence of H. pylori isolated in North, Central and South America, we found evidence for admixture between H. pylori of European and African origin throughout the Americas, without substantial input from pre-Columbian (hspAmerind) bacteria. In the US, strains of African and European origin have remained genetically distinct, while in Colombia and Nicaragua, bottlenecks and rampant genetic exchange amongst isolates have led to the formation of national gene pools. We found three outer membrane proteins with atypical levels of Asian ancestry in American strains, as well as alleles that were nearly fixed specifically in South American isolates, suggesting a role for the ethnic makeup of hosts in the colonization of incoming strains. Our results show that new H. pylori subpopulations can rapidly arise, spread and adapt during times of demographic flux, and suggest that differences in transmission ecology between high and low prevalence areas may substantially affect the composition of bacterial populations. Helicobacter pylori is one of the best studied examples of an intimate association between bacteria and humans, due to its ability to colonize the stomach for decades and to transmit from generation to generation. A number of studies have sought to link diversity in H. pylori to human migrations but there are some discordant signals such as an “out of Africa” dispersal within the last few thousand years that has left a much stronger signal in bacterial genomes than in human ones. In order to understand how such discrepancies arise, we have investigated the evolution of H. pylori during the recent colonization of the Americas. We find that bacterial populations evolve quickly and can spread rapidly to people of different ethnicities. Distinct new bacterial subpopulations have formed in Colombia from a European source and in Nicaragua and the US from African sources. Genetic exchange between bacterial populations is rampant within Central and South America but is uncommon within North America, which may reflect differences in prevalence. Our results also suggest that adaptation of bacteria to particular human ethnic groups may be confined to a handful of genes involved in interaction with the immune system.
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Affiliation(s)
- Kaisa Thorell
- Microbiology, Tumour and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Koji Yahara
- Dept. of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Elvire Berthenet
- Medical Microbiology and Infectious Disease group, Swansea University, Swansea, Wales, United Kingdom
| | - Daniel J. Lawson
- Integrative Epidemiology Unit, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Jane Mikhail
- Medical Microbiology and Infectious Disease group, Swansea University, Swansea, Wales, United Kingdom
| | - Ikuko Kato
- Karmanos Cancer Institute, Wayne State University, Detroit, Michigan, United States of America
| | - Alfonso Mendez
- Instituto Politecnico Nacional, ENCB, Mexico City, Mexico
| | - Cosmeri Rizzato
- Dipartimento di Ricerca Traslazionale e Nuove Tecnologie in Medicina e Chirurgia, Universitá di Pisa, Pisa, Italy
| | - María Mercedes Bravo
- Grupo de Investigación en Biología del Cáncer, Instituto Nacional de Cancerología, Bogota, Colombia
| | - Rumiko Suzuki
- Dept. of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Yoshio Yamaoka
- Dept. of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Javier Torres
- Unidad de Investigación en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico City, Mexico
| | - Samuel K. Sheppard
- Milner Center for Evolution, Dept. of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Daniel Falush
- Milner Center for Evolution, Dept. of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- * E-mail:
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33
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Lee WC, Goh KL, Loke MF, Vadivelu J. Elucidation of the Metabolic Network of Helicobacter pylori J99 and Malaysian Clinical Strains by Phenotype Microarray. Helicobacter 2017; 22:e12321. [PMID: 27258354 PMCID: PMC5248604 DOI: 10.1111/hel.12321] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Helicobacter pylori colonizes almost half of the human population worldwide. H. pylori strains are genetically diverse, and the specific genotypes are associated with various clinical manifestations including gastric adenocarcinoma, peptic ulcer disease (PUD), and nonulcer dyspepsia (NUD). However, our current knowledge of the H. pylori metabolism is limited. To understand the metabolic differences among H. pylori strains, we investigated four Malaysian H. pylori clinical strains, which had been previously sequenced, and a standard strain, H. pylori J99, at the phenotypic level. MATERIALS AND METHODS The phenotypes of the H. pylori strains were profiled using the Biolog Phenotype Microarray system to corroborate genomic data. We initiated the analyses by predicting carbon and nitrogen metabolic pathways from the H. pylori genomic data from the KEGG database. Biolog PM aided the validation of the prediction and provided a more intensive analysis of the H. pylori phenomes. RESULTS We have identified a core set of metabolic nutrient sources that was utilized by all strains tested and another set that was differentially utilized by only the local strains. Pentose sugars are the preferred carbon nutrients utilized by H. pylori. The amino acids l-aspartic acid, d-alanine, and l-asparagine serve as both carbon and nitrogen sources in the metabolism of the bacterium. CONCLUSION The phenotypic profile based on this study provides a better understanding on the survival of H. pylori in its natural host. Our data serve as a foundation for future challenges in correlating interstrain metabolic differences in H. pylori.
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Affiliation(s)
- Woon Ching Lee
- Faculty of MedicineDepartment of Medical MicrobiologyUniversity of MalayaKuala LumpurMalaysia
| | - Khean Lee Goh
- Faculty of MedicineDepartment of MedicineUniversity of MalayaKuala LumpurMalaysia
| | - Mun Fai Loke
- Faculty of MedicineDepartment of Medical MicrobiologyUniversity of MalayaKuala LumpurMalaysia
| | - Jamuna Vadivelu
- Faculty of MedicineDepartment of Medical MicrobiologyUniversity of MalayaKuala LumpurMalaysia
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34
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Bi H, Zhu L, Jia J, Zeng L, Cronan JE. Unsaturated Fatty Acid Synthesis in the Gastric Pathogen Helicobacter pylori Proceeds via a Backtracking Mechanism. Cell Chem Biol 2016; 23:1480-1489. [PMID: 27866909 DOI: 10.1016/j.chembiol.2016.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 08/26/2016] [Accepted: 10/14/2016] [Indexed: 12/13/2022]
Abstract
Helicobacter pylori is a Gram-negative bacterium that inhabits the upper gastrointestinal tract in humans, and the presence of this pathogen in the gut microbiome increases the risk of peptic ulcers and stomach cancer. H. pylori depends on unsaturated fatty acid (UFA) biosynthesis for maintaining membrane structure and function. Although some of the H. pylori enzymes involved in UFA biosynthesis are functionally homologous with the enzymes found in Escherichia coli, we show here that an enzyme HP0773, now annotated as FabX, uses an unprecedented backtracking mechanism to not only dehydrogenate decanoyl-acyl carrier protein (ACP) in a reaction that parallels that of acyl-CoA dehydrogenase, the first enzyme of the fatty acid β-oxidation cycle, but also isomerizes trans-2-decenoyl-ACP to cis-3-decenoyl-ACP, the key UFA synthetic intermediate. Thus, FabX reverses the normal fatty acid synthesis cycle in H. pylori at the C10 stage. Overall, this unusual FabX activity may offer a broader explanation for how many bacteria that lack the canonical pathway enzymes produce UFA-containing phospholipids.
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Affiliation(s)
- Hongkai Bi
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China; Department of Pathogen Biology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China.
| | - Lei Zhu
- Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA
| | - Jia Jia
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China; Department of Pathogen Biology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China
| | - Liping Zeng
- Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China; Department of Pathogen Biology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China
| | - John E Cronan
- Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA; Department of Biochemistry, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA.
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Flint A, Stintzi A, Saraiva LM. Oxidative and nitrosative stress defences of Helicobacter and Campylobacter species that counteract mammalian immunity. FEMS Microbiol Rev 2016; 40:938-960. [PMID: 28201757 PMCID: PMC5091033 DOI: 10.1093/femsre/fuw025] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/29/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022] Open
Abstract
Helicobacter and Campylobacter species are Gram-negative microaerophilic host-associated heterotrophic bacteria that invade the digestive tract of humans and animals. Campylobacter jejuni is the major worldwide cause of foodborne gastroenteritis in humans, while Helicobacter pylori is ubiquitous in over half of the world's population causing gastric and duodenal ulcers. The colonisation of the gastrointestinal system by Helicobacter and Campylobacter relies on numerous cellular defences to sense the host environment and respond to adverse conditions, including those imposed by the host immunity. An important antimicrobial tool of the mammalian innate immune system is the generation of harmful oxidative and nitrosative stresses to which pathogens are exposed during phagocytosis. This review summarises the regulators, detoxifying enzymes and subversion mechanisms of Helicobacter and Campylobacter that ultimately promote the successful infection of humans.
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Affiliation(s)
- Annika Flint
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica, NOVA, Av. da República, 2780-157 Oeiras, Portugal
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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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Foegeding NJ, Caston RR, McClain MS, Ohi MD, Cover TL. An Overview of Helicobacter pylori VacA Toxin Biology. Toxins (Basel) 2016; 8:toxins8060173. [PMID: 27271669 PMCID: PMC4926140 DOI: 10.3390/toxins8060173] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/18/2016] [Accepted: 05/27/2016] [Indexed: 12/11/2022] Open
Abstract
The VacA toxin secreted by Helicobacter pylori enhances the ability of the bacteria to colonize the stomach and contributes to the pathogenesis of gastric adenocarcinoma and peptic ulcer disease. The amino acid sequence and structure of VacA are unrelated to corresponding features of other known bacterial toxins. VacA is classified as a pore-forming toxin, and many of its effects on host cells are attributed to formation of channels in intracellular sites. The most extensively studied VacA activity is its capacity to stimulate vacuole formation, but the toxin has many additional effects on host cells. Multiple cell types are susceptible to VacA, including gastric epithelial cells, parietal cells, T cells, and other types of immune cells. This review focuses on the wide range of VacA actions that are detectable in vitro, as well as actions of VacA in vivo that are relevant for H. pylori colonization of the stomach and development of gastric disease.
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Affiliation(s)
- Nora J Foegeding
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Rhonda R Caston
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Mark S McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Melanie D Ohi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Timothy L Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
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Bhattacharya S, Mukherjee O, Mukhopadhyay AK, Chowdhury R, Pal AK, Dhar KK. A Conserved Helicobacter pylori Gene, HP0102, Is Induced Upon Contact With Gastric Cells and Has Multiple Roles in Pathogenicity. J Infect Dis 2016; 214:196-204. [PMID: 27056952 DOI: 10.1093/infdis/jiw139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/30/2016] [Indexed: 01/13/2023] Open
Abstract
Contact with host cells is recognized as a signal capable of triggering expression of bacterial genes important for host pathogen interaction. Adherence of Helicobacter pylori to the gastric epithelial cell line AGS strongly upregulated expression of a gene, HP0102, in the adhered bacteria in all strains examined, including several Indian clinical isolates. The gene is highly conserved and ubiquitously present in all 69 sequenced H. pylori genomes at the same genomic locus, as well as in 15 Indian clinical isolates. The gene is associated with 2 distinct phenotypes related to pathogenicity. In AGS cell-adhered H. pylori, it has a role in upregulation of cagA expression from a specific σ(28)-RNAP promoter and consequent induction of the hummingbird phenotype in the infected AGS cells. Furthermore, HP0102 has a role in chemotaxis and a ΔHP0102 mutant exhibited low acid-escape response that might account for the poor colonization efficiency of the mutant.
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Affiliation(s)
- Saurabh Bhattacharya
- Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology
| | - Oindrilla Mukherjee
- Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology
| | - Asish K Mukhopadhyay
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Rukhsana Chowdhury
- Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology
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A Biotin Biosynthesis Gene Restricted to Helicobacter. Sci Rep 2016; 6:21162. [PMID: 26868423 PMCID: PMC4751477 DOI: 10.1038/srep21162] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/12/2016] [Indexed: 02/07/2023] Open
Abstract
In most bacteria the last step in synthesis of the pimelate moiety of biotin is cleavage of the ester bond of pimeloyl-acyl carrier protein (ACP) methyl ester. The paradigm cleavage enzyme is Escherichia coli BioH which together with the BioC methyltransferase allows synthesis of the pimelate moiety by a modified fatty acid biosynthetic pathway. Analyses of the extant bacterial genomes showed that bioH is absent from many bioC-containing bacteria and is replaced by other genes. Helicobacter pylori lacks a gene encoding a homologue of the known pimeloyl-ACP methyl ester cleavage enzymes suggesting that it encodes a novel enzyme that cleaves this intermediate. We isolated the H. pylori gene encoding this enzyme, bioV, by complementation of an E. coli bioH deletion strain. Purified BioV cleaved the physiological substrate, pimeloyl-ACP methyl ester to pimeloyl-ACP by use of a catalytic triad, each member of which was essential for activity. The role of BioV in biotin biosynthesis was demonstrated using a reconstituted in vitro desthiobiotin synthesis system. BioV homologues seem the sole pimeloyl-ACP methyl ester esterase present in the Helicobacter species and their occurrence only in H. pylori and close relatives provide a target for development of drugs to specifically treat Helicobacter infections.
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40
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Koch KN, Müller A. Helicobacter pylori activates the TLR2/NLRP3/caspase-1/IL-18 axis to induce regulatory T-cells, establish persistent infection and promote tolerance to allergens. Gut Microbes 2016; 6:382-7. [PMID: 26727421 PMCID: PMC4826104 DOI: 10.1080/19490976.2015.1105427] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The Gram-negative bacterium Helicobacter pylori is both a normal constituent of the human gastric microbiota as well as a pathogen tightly associated with severe gastric disorders. The ability of H. pylori to activate the inflammasome and caspase-1 in antigen-presenting and other cells, and the resulting processing and release of caspase-1-dependent cytokines, impacts both the immunomodulatory and pathogenic activities of H. pylori. This article summarizes recent insights by us and others on the bacterial and host prerequisites of inflammasome activation. H. pylori predominantly activates the NLRP3 inflammasome through a process that requires TLR2-dependent licensing. We identified the urease enzyme, a colonization determinant known to be required for acid adaptation, as critically required for activation of the TLR2/NLRP3/caspase-1 axis. The phenotypes of urease mutants, as well as mouse strains defective for TLR2 or NLRP3, are discussed with respect to their ability to support persistent colonization, immune tolerance and immunity to H. pylori.
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Affiliation(s)
- Katrin N Koch
- Institute of Molecular Cancer Research; University of Zurich; Zurich, Switzerland
| | - Anne Müller
- Institute of Molecular Cancer Research; University of Zurich; Zurich, Switzerland,Correspondence to: Anne Müller;
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41
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Helicobacter pylori adaptation in vivo in response to a high-salt diet. Infect Immun 2015; 83:4871-83. [PMID: 26438795 DOI: 10.1128/iai.00918-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/30/2015] [Indexed: 12/21/2022] Open
Abstract
Helicobacter pylori exhibits a high level of intraspecies genetic diversity. In this study, we investigated whether the diversification of H. pylori is influenced by the composition of the diet. Specifically, we investigated the effect of a high-salt diet (a known risk factor for gastric adenocarcinoma) on H. pylori diversification within a host. We analyzed H. pylori strains isolated from Mongolian gerbils fed either a high-salt diet or a regular diet for 4 months by proteomic and whole-genome sequencing methods. Compared to the input strain and output strains from animals fed a regular diet, the output strains from animals fed a high-salt diet produced higher levels of proteins involved in iron acquisition and oxidative-stress resistance. Several of these changes were attributable to a nonsynonymous mutation in fur (fur-R88H). Further experiments indicated that this mutation conferred increased resistance to high-salt conditions and oxidative stress. We propose a model in which a high-salt diet leads to high levels of gastric inflammation and associated oxidative stress in H. pylori-infected animals and that these conditions, along with the high intraluminal concentrations of sodium chloride, lead to selection of H. pylori strains that are most fit for growth in this environment.
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Voss BJ, Loh JT, Hill S, Rose KL, McDonald WH, Cover TL. Alteration of the Helicobacter pylori membrane proteome in response to changes in environmental salt concentration. Proteomics Clin Appl 2015; 9:1021-34. [PMID: 26109032 DOI: 10.1002/prca.201400176] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 05/18/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022]
Abstract
PURPOSE Helicobacter pylori infection and a high dietary salt intake are each risk factors for the development of gastric cancer. We hypothesize that changes in environmental salt concentrations lead to alterations in the H. pylori membrane proteome. EXPERIMENTAL DESIGN Label-free and iTRAQ methods were used to identify H. pylori proteins that change in abundance in response to alterations in environmental salt concentrations. In addition, we biotinylated intact bacteria that were grown under high- or low-salt conditions, and thereby analyzed salt-induced changes in the abundance of surface-exposed proteins. RESULTS Proteins with increased abundance in response to high salt conditions included CagA, the outer membrane protein HopQ, and fibronectin domain-containing protein HP0746. Proteins with increased abundance in response to low salt conditions included VacA, two VacA-like proteins (ImaA and FaaA), outer-membrane iron transporter FecA3, and several proteins involved in flagellar activity. Consistent with the proteomic data, bacteria grown in high salt conditions exhibited decreased motility compared to bacteria grown in lower salt conditions. CONCLUSION AND CLINICAL RELEVANCE Alterations in the H. pylori membrane proteome in response to high salt conditions may contribute to the increased risk of gastric cancer associated with a high salt diet.
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Affiliation(s)
- Bradley J Voss
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - John T Loh
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Salisha Hill
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kristie L Rose
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - W Hayes McDonald
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Timothy L Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA
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Ud-Din AI, Liu YC, Roujeinikova A. Crystal structure of Helicobacter pylori pseudaminic acid biosynthesis N-acetyltransferase PseH: implications for substrate specificity and catalysis. PLoS One 2015; 10:e0115634. [PMID: 25781966 PMCID: PMC4363471 DOI: 10.1371/journal.pone.0115634] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 11/25/2014] [Indexed: 01/15/2023] Open
Abstract
Helicobacter pylori infection is the common cause of gastroduodenal diseases linked to a higher risk of the development of gastric cancer. Persistent infection requires functional flagella that are heavily glycosylated with 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-nonulosonic acid (pseudaminic acid). Pseudaminic acid biosynthesis protein H (PseH) catalyzes the third step in its biosynthetic pathway, producing UDP-2,4-diacetamido-2,4,6-trideoxy-β-L-altropyranose. It belongs to the GCN5-related N-acetyltransferase (GNAT) superfamily. The crystal structure of the PseH complex with cofactor acetyl-CoA has been determined at 2.3 Å resolution. This is the first crystal structure of the GNAT superfamily member with specificity to UDP-4-amino-4,6-dideoxy-β-L-AltNAc. PseH is a homodimer in the crystal, each subunit of which has a central twisted β-sheet flanked by five α-helices and is structurally homologous to those of other GNAT superfamily enzymes. Interestingly, PseH is more similar to the GNAT enzymes that utilize amino acid sulfamoyl adenosine or protein as a substrate than a different GNAT-superfamily bacterial nucleotide-sugar N-acetyltransferase of the known structure, WecD. Analysis of the complex of PseH with acetyl-CoA revealed the location of the cofactor-binding site between the splayed strands β4 and β5. The structure of PseH, together with the conservation of the active-site general acid among GNAT superfamily transferases, are consistent with a common catalytic mechanism for this enzyme that involves direct acetyl transfer from AcCoA without an acetylated enzyme intermediate. Based on structural homology with microcin C7 acetyltransferase MccE and WecD, the Michaelis complex can be modeled. The model suggests that the nucleotide- and 4-amino-4,6-dideoxy-β-L-AltNAc-binding pockets form extensive interactions with the substrate and are thus the most significant determinants of substrate specificity. A hydrophobic pocket accommodating the 6'-methyl group of the altrose dictates preference to the methyl over the hydroxyl group and thus to contributes to substrate specificity of PseH.
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Affiliation(s)
- Abu I Ud-Din
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Yu C. Liu
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Anna Roujeinikova
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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Datta De D, Roychoudhury S. To be or not to be: The host genetic factor and beyond in Helicobacter pylori mediated gastro-duodenal diseases. World J Gastroenterol 2015; 21:2883-2895. [PMID: 25780285 PMCID: PMC4356907 DOI: 10.3748/wjg.v21.i10.2883] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/28/2014] [Accepted: 01/08/2015] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) have long been associated with a spectrum of disease outcomes in the gastro-duodenal system. Heterogeneity in bacterial virulence factors or strains is not enough to explain the divergent disease phenotypes manifested by the infection. This review focuses on host genetic factors that are involved during infection and eventually are thought to influence the disease phenotype. We have summarized the different host genes that have been investigated for association studies in H. pylori mediated duodenal ulcer or gastric cancer. We discuss that as the bacteria co-evolved with the host; these host gene also show much variation across different ethnic population. We illustrate the allelic distribution of interleukin-1B, across different population which is one of the most popular candidate gene studied with respect to H. pylori infections. Further, we highlight that several polymorphisms in the pathway gene can by itself or collectively affect the acid secretion pathway axis (gastrin: somatostatin) thereby resulting in a spectrum of disease phenotype
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45
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van der Veen S, Tang CM. The BER necessities: the repair of DNA damage in human-adapted bacterial pathogens. Nat Rev Microbiol 2015; 13:83-94. [PMID: 25578955 DOI: 10.1038/nrmicro3391] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
During colonization and disease, bacterial pathogens must survive the onslaught of the host immune system. A key component of the innate immune response is the generation of reactive oxygen and nitrogen species by phagocytic cells, which target and disrupt pathogen molecules, particularly DNA, and the base excision repair (BER) pathway is the most important mechanism for the repair of such oxidative DNA damage. In this Review, we discuss how the human-specific pathogens Mycobacterium tuberculosis, Helicobacter pylori and Neisseria meningitidis have evolved specialized mechanisms of DNA repair, particularly their BER pathways, compared with model organisms such as Escherichia coli. This specialization in DNA repair is likely to reflect the distinct niches occupied by these important human pathogens in the host.
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Affiliation(s)
- Stijn van der Veen
- Sir William Dunn School of Pathology, South Parks Road, University of Oxford, Oxford, OX1 3RE, UK
| | - Christoph M Tang
- Sir William Dunn School of Pathology, South Parks Road, University of Oxford, Oxford, OX1 3RE, UK
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46
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Kao CY, Sheu BS, Wu JJ. CsrA regulates Helicobacter pylori J99 motility and adhesion by controlling flagella formation. Helicobacter 2014; 19:443-54. [PMID: 25109343 DOI: 10.1111/hel.12148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Motility mediated by the flagella of Helicobacter pylori has been shown to be required for normal colonization and is thought to be important for the bacteria to move toward the gastric mucus in niches adjacent to the epithelium. Barnard et al. showed that CsrA appears to be necessary for full motility and the ability to infect mice, but its mechanism of regulation is still unclear. METHODS Motility and cell adhesion ability were determined in wild-type, csrA mutant, and revertant J99 strains. The bacterial shape and flagellar structure were evaluated by transmission electron microscopy. The expression of two major flagellins, flaA/flaB, and the alternative sigma factor rpoN (σ(54)) were determined by real-time quantitative RT-PCR and Western blot. RESULTS The csrA mutant showed loss of motility and lower adhesion ability compared with the wild-type and revertant J99 strains. The csrA mutant was not flagellated. Transcription of flaA and flaB mRNA decreased to only 40% and 16%, respectively, in the csrA mutant compared with the wild-type J99 (p = .006 and <.0001, respectively), and Western blot analysis showed dramatically reduced FlaA/FlaB proteins in a csrA mutant. The disruption of csrA also decreased expression of rpoN to 48% in the csrA mutant, but the degradation rate of rpoN mRNA was not changed. CONCLUSION These results suggest that CsrA regulates H. pylori J99 flagella formation and thereby affects bacterial motility.
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Affiliation(s)
- Cheng-Yen Kao
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Al-Haddad S, El-Zimaity H, Hafezi-Bakhtiari S, Rajendra S, Streutker CJ, Vajpeyi R, Wang B. Infection and esophageal cancer. Ann N Y Acad Sci 2014; 1325:187-96. [PMID: 25266025 DOI: 10.1111/nyas.12530] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.
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Affiliation(s)
- Sahar Al-Haddad
- Department of Laboratory Medicine, St. Michael's Hospital and the University of Toronto, Toronto, Canada
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48
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Liu YC, Ud-Din AI, Roujeinikova A. Cloning, purification and preliminary crystallographic analysis of the Helicobacter pylori pseudaminic acid biosynthesis N-acetyltransferase PseH. Acta Crystallogr F Struct Biol Commun 2014; 70:1276-9. [PMID: 25195909 PMCID: PMC4157436 DOI: 10.1107/s2053230x14015398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/01/2014] [Indexed: 01/05/2023] Open
Abstract
Helicobacter pylori infection is the common cause of gastritis and duodenal and stomach ulcers, which have been linked to a higher risk of the development of gastric cancer. The motility that facilitates persistent infection requires functional flagella that are heavily glycosylated with 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-nonulosonic acid (pseudaminic acid). Pseudaminic acid biosynthesis protein H (PseH) catalyzes the third step in its biosynthetic pathway, producing UDP-2,4-diacetamido-2,4,6-trideoxy-β-L-altropyranose. Crystals of H. pylori PseH have been grown by the hanging-drop vapour-diffusion method using diammonium tartrate as a precipitating agent. The crystals belonged to space group I222 or I212121, with unit-cell parameters a = 107.8, b = 145.4, c = 166.3 Å. A complete X-ray diffraction data set has been collected to 2.5 Å resolution using cryocooling conditions and synchrotron radiation.
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Affiliation(s)
- Yu C. Liu
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Abu I. Ud-Din
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Anna Roujeinikova
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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49
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Iwatani S, Nagashima H, Reddy R, Shiota S, Graham DY, Yamaoka Y. Identification of the genes that contribute to lactate utilization in Helicobacter pylori. PLoS One 2014; 9:e103506. [PMID: 25078575 PMCID: PMC4117512 DOI: 10.1371/journal.pone.0103506] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/30/2014] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori are Gram-negative, spiral-shaped microaerophilic bacteria etiologically related to gastric cancer. Lactate utilization has been implicated although no corresponding genes have been identified in the H. pylori genome. Here, we report that gene products of hp0137–0139 (lldEFG), hp0140–0141 (lctP), and hp1222 (dld) contribute to D- and L-lactate utilization in H. pylori. The three-gene unit hp0137–0139 in H. pylori 26695 encodes L-lactate dehydrogenase (LDH) that catalyzes the conversion of lactate to pyruvate in an NAD-dependent manner. Isogenic mutants of these genes were unable to grow on L-lactate-dependent medium. The hp1222 gene product functions as an NAD-independent D-LDH and also contributes to the oxidation of L-lactate; the isogenic mutant of this gene failed to grow on D-lactate-dependent medium. The parallel genes hp0140–0141 encode two nearly identical lactate permeases (LctP) that promote uptake of both D- and L-lactate. Interestingly an alternate route must also exist for lactate transport as the knockout of genes did not completely prevent growth on D- or L-lactate. Gene expression levels of hp0137–0139 and hp1222 were not enhanced by lactate as the carbon source. Expression of hp0140–0141 was slightly suppressed in the presence of L-lactate but not D-lactate. This study identified the genes contributing to the lactate utilization and demonstrated the ability of H. pylori to utilize both D- and L-lactate.
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Affiliation(s)
- Shun Iwatani
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Hiroyuki Nagashima
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Rita Reddy
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
| | - Seiji Shiota
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - David Y. Graham
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
| | - Yoshio Yamaoka
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
- * E-mail:
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Gao B, Lara-Tejero M, Lefebre M, Goodman AL, Galán JE. Novel components of the flagellar system in epsilonproteobacteria. mBio 2014; 5:e01349-14. [PMID: 24961693 PMCID: PMC4073491 DOI: 10.1128/mbio.01349-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 06/02/2014] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Motility is essential for the pathogenesis of many bacterial species. Most bacteria move using flagella, which are multiprotein filaments that rotate propelled by a cell wall-anchored motor using chemical energy. Although some components of the flagellar apparatus are common to many bacterial species, recent studies have shown significant differences in the flagellar structures of different bacterial species. The molecular bases for these differences, however, are not understood. The flagella from epsilonproteobacteria, which include the bacterial pathogens Campylobacter jejuni and Helicobacter pylori, are among the most divergent. Using next-generation sequencing combined with transposon mutagenesis, we have conducted a comprehensive high-throughput genetic screen in Campylobacter jejuni, which identified several novel components of its flagellar system. Biochemical analyses detected interactions between the identified proteins and known components of the flagellar machinery, and in vivo imaging located them to the bacterial poles, where flagella assemble. Most of the identified new components are conserved within but restricted to epsilonproteobacteria. These studies provide insight into the divergent flagella of this group of bacteria and highlight the complexity of this remarkable structure, which has adapted to carry out its conserved functions in the context of widely diverse bacterial species. IMPORTANCE Motility is essential for the normal physiology and pathogenesis of many bacterial species. Most bacteria move using flagella, which are multiprotein filaments that rotate propelled by a motor that uses chemical energy as fuel. Although some components of the flagellar apparatus are common to many bacterial species, recent studies have shown significant divergence in the flagellar structures across bacterial species. However, the molecular bases for these differences are not understood. The flagella from epsilonproteobacteria, which include the bacterial pathogens Campylobacter jejuni and Helicobacter pylori, are among the most divergent. We conducted a comprehensive genetic screen in Campylobacter jejuni and identified several novel components of the flagellar system. These studies provide important information to understand how flagella have adapted to function in the context of widely diverse sets of bacterial species and bring unique insight into the evolution and function of this remarkable bacterial organelle.
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Affiliation(s)
- Beile Gao
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Maria Lara-Tejero
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Matthew Lefebre
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Jorge E Galán
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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