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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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Aoki S, Mori S, Matsui H, Shibayama K, Kenri T, Rimbara E. Characterization of HcaA, a novel autotransporter protein in Helicobacter cinaedi, and its role in host cell adhesion. mSphere 2023; 8:e0040323. [PMID: 38009997 PMCID: PMC10732068 DOI: 10.1128/msphere.00403-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/07/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Helicobacter species are classified as gastric or enterohepatic according to their habitat. Among enterohepatic Helicobacter species, which inhabit the intestine, colon, and liver, Helicobacter cinaedi has been most frequently isolated from humans. H. cinaedi often causes bacteremia and cellulitis in immunocompromised hosts. Here, we focused on the H. cinaedi autotransporter protein A (HcaA), a novel virulence factor in H. cinaedi. We discovered that HcaA contributes to cell adhesion via its Arg-Gly-Asp motif. Furthermore, in animal experiments, bacterial colonization was reduced in mice infected with HcaA-knockout strains, supporting the hypothesis that HcaA contributes to H. cinaedi adhesion to host cells. Our study provides a novel mechanism for the establishment of H. cinaedi infections and provides new insights into the role of autotransporter proteins in the establishment of Helicobacter infection.
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Affiliation(s)
- Sae Aoki
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shigetarou Mori
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hidenori Matsui
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keigo Shibayama
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Tsuyoshi Kenri
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Emiko Rimbara
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
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Rosli NA, Al-Maleki AR, Loke MF, Chua EG, Alhoot MA, Vadivelu J. Polymorphism of virulence genes and biofilm associated with in vitro induced resistance to clarithromycin in Helicobacter pylori. Gut Pathog 2023; 15:52. [PMID: 37898785 PMCID: PMC10613384 DOI: 10.1186/s13099-023-00579-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/19/2023] [Indexed: 10/30/2023] Open
Abstract
BACKGROUND Clarithromycin-containing triple therapy is commonly used to treat Helicobacter pylori infections. Clarithromycin resistance is the leading cause of H. pylori treatment failure. Understanding the specific mutations that occur in H. pylori strains that have evolved antibiotic resistance can help create a more effective and individualised antibiotic treatment plan. However, little is understood about the genetic reprogramming linked to clarithromycin exposure and the emergence of antibiotic resistance in H. pylori. Therefore, this study aims to identify compensatory mutations and biofilm formation associated with the development of clarithromycin resistance in H. pylori. Clarithromycin-sensitive H. pylori clinical isolates were induced to develop clarithromycin resistance through in vitro exposure to incrementally increasing concentration of the antibiotic. The genomes of the origin sensitive isolates (S), isogenic breakpoint (B), and resistant isolates (R) were sequenced. Single nucleotide variations (SNVs), and insertions or deletions (InDels) associated with the development of clarithromycin resistance were identified. Growth and biofilm production were also assessed. RESULTS The S isolates with A2143G mutation in the 23S rRNA gene were successfully induced to be resistant. According to the data, antibiotic exposure may alter the expression of certain genes, including those that code for the Cag4/Cag protein, the vacuolating cytotoxin domain-containing protein, the sel1 repeat family protein, and the rsmh gene, which may increase the risk of developing and enhances virulence in H. pylori. Enhanced biofilm formation was detected among R isolates compared to B and S isolates. Furthermore, high polymorphism was also detected among the genes associated with biofilm production. CONCLUSIONS Therefore, this study suggests that H. pylori may acquire virulence factors while also developing antibiotic resistance due to clarithromycin exposure.
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Affiliation(s)
- Naim Asyraf Rosli
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Anis Rageh Al-Maleki
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.
| | - Mun Fai Loke
- Camtech Biomedical Pte Ltd, Singapore, Singapore
| | - Eng Guan Chua
- School of Biomedical Sciences, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Perth, WA, Australia
| | - Mohammed Abdelfatah Alhoot
- Faculty of Pharmacy, Airlangga University, Surabaya, 60155, Indonesia
- School of Graduate Studies, Management & Science University, Shah Alam, Selangor, Malaysia
| | - Jamuna Vadivelu
- Medical Education Research and Development Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
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Díaz-Rullo J, González-Pastor JE. tRNA queuosine modification is involved in biofilm formation and virulence in bacteria. Nucleic Acids Res 2023; 51:9821-9837. [PMID: 37638766 PMCID: PMC10570037 DOI: 10.1093/nar/gkad667] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/27/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023] Open
Abstract
tRNA modifications are crucial for fine-tuning of protein translation. Queuosine (Q) modification of tRNAs is thought to modulate the translation rate of NAU codons, but its physiological role remains elusive. Therefore, we hypothesize that Q-tRNAs control those physiological processes involving NAU codon-enriched genes (Q-genes). Here, we report a novel bioinformatic strategy to predict Q-genes, revealing a widespread enrichment in functions, especially those related to biofilm formation and virulence in bacteria, and particularly in human pathogens. Indeed, we experimentally verified that these processes were significantly affected by altering the degree of tRNA Q-modification in different model bacteria, representing the first report of a general mechanism controlling biofilm formation and virulence in Gram-positive and Gram-negative bacteria possibly through the coordination of the expression of functionally related genes. Furthermore, we propose that changes in Q availability in a microbiome would affect its functionality. Our findings open the door to the control of bacterial infections and biofilm formation by inhibition of tRNA Q-modification.
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Affiliation(s)
- Jorge Díaz-Rullo
- Department of Molecular Evolution, Centro de Astrobiología (CAB), CSIC-INTA, Carretera de Ajalvir km 4, Torrejón de Ardoz 28850, Madrid, Spain
| | - José Eduardo González-Pastor
- Department of Molecular Evolution, Centro de Astrobiología (CAB), CSIC-INTA, Carretera de Ajalvir km 4, Torrejón de Ardoz 28850, Madrid, Spain
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Gibson KH, Botting JM, Al-Otaibi N, Maitre K, Bergeron J, Starai VJ, Hoover TR. Control of the flagellation pattern in Helicobacter pylori by FlhF and FlhG. J Bacteriol 2023; 205:e0011023. [PMID: 37655916 PMCID: PMC10521351 DOI: 10.1128/jb.00110-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/06/2023] [Indexed: 09/02/2023] Open
Abstract
FlhF and FlhG control the location and number of flagella, respectively, in many polar-flagellated bacteria. The roles of FlhF and FlhG are not well characterized in bacteria that have multiple polar flagella, such as Helicobacter pylori. Deleting flhG in H. pylori shifted the flagellation pattern where most cells had approximately four flagella to a wider and more even distribution in flagellar number. As reported in other bacteria, deleting flhF in H. pylori resulted in reduced motility, hypoflagellation, and the improper localization of flagella to nonpolar sites. Motile variants of H. pylori ∆flhF mutants that had a higher proportion of flagella localizing correctly to the cell pole were isolated, but we were unable to identify the genetic determinants responsible for the increased localization of flagella to the cell pole. One motile variant though produced more flagella than the ΔflhF parental strain, which apparently resulted from a missense mutation in fliF (encodes the MS ring protein), which changed Asn-255 to aspartate. Recombinant FliFN255D, but not recombinant wild-type FliF, formed ordered ring-like assemblies in vitro that were ~50 nm wide and displayed the MS ring architecture. We infer from these findings that the FliFN225D variant forms the MS ring more effectively in vivo in the absence of FlhF than wild-type FliF. IMPORTANCE Helicobacter pylori colonizes the human stomach where it can cause a variety of diseases, including peptic ulcer disease and gastric cancer. H. pylori uses flagella for motility, which is required for host colonization. FlhG and FlhF control the flagellation patterns in many bacteria. We found that in H. pylori, FlhG ensures that cells have approximately equal number of flagella and FlhF is needed for flagellum assembly and localization. FlhF is proposed to facilitate the assembly of FliF into the MS ring, which is one of the earliest structures formed in flagellum assembly. We identified a FliF variant that assembles the MS ring in the absence of FlhF, which supports the proposed role of FlhF in facilitating MS ring assembly.
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Affiliation(s)
| | - Jack M. Botting
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Natalie Al-Otaibi
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Kriti Maitre
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Julien Bergeron
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Vincent J. Starai
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
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Saruuljavkhlan B, Alfaray RI, Oyuntsetseg K, Gantuya B, Khangai A, Renchinsengee N, Matsumoto T, Akada J, Azzaya D, Davaadorj D, Yamaoka Y. Study of Helicobacter pylori Isolated from a High-Gastric-Cancer-Risk Population: Unveiling the Comprehensive Analysis of Virulence-Associated Genes including Secretion Systems, and Genome-Wide Association Study. Cancers (Basel) 2023; 15:4528. [PMID: 37760497 PMCID: PMC10526929 DOI: 10.3390/cancers15184528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/25/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND The prevalence of gastric cancer in Mongolia, in East Asia, remains the highest in the world. However, most Helicobacter pylori strains in Mongolia have a less virulent Western-type CagA. We aimed to determine how H. pylori genomic variation affected gastric diseases, especially gastric cancer, based on comprehensive genome analysis. METHODS We identified a set of 274 virulence-associated genes in H. pylori, including virulence factor and outer membrane protein (OMP) genes, the type four secretion system gene cluster, and 13 well-known virulence gene genotypes in 223 H. pylori strains and their associations with gastric cancer and other gastric diseases. We conducted a genome-wide association study on 158 H. pylori strains (15 gastric cancer and 143 non-gastric cancer strains). RESULTS Out of 274 genes, we found 13 genes were variable depending on disease outcome, especially iron regulating OMP genes. H. pylori strains from Mongolia were divided into two main subgroups: subgroup (Sg1) with high risk and Sg2 with low risk for gastric cancer. The general characteristics of Sg1 strains are that they possess more virulence genotype genes. We found nine non-synonymous single nucleotide polymorphisms in seven genes that are linked with gastric cancer strains. CONCLUSIONS Highly virulent H. pylori strains may adapt through host-influenced genomic variations, potentially impacting gastric carcinogenesis.
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Grants
- 18KK0266, 19H03473, 21H00346, 22H02871, 17K09353, 21K07898, 18K16182, 21K08010 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- 2021B13 Research Center for GLOBAL and LOCAL Infectious Diseases, Oita University
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Affiliation(s)
- Batsaikhan Saruuljavkhlan
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
| | - Ricky Indra Alfaray
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, East Java, Indonesia
| | - Khasag Oyuntsetseg
- Endoscopy Center, Mongolia Japan Hospital, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (K.O.); (B.G.)
| | - Boldbaatar Gantuya
- Endoscopy Center, Mongolia Japan Hospital, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (K.O.); (B.G.)
- Department of Gastroenterology and Hepatology, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (D.A.); (D.D.)
| | - Ayush Khangai
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
| | - Namsrai Renchinsengee
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
| | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
| | - Dashdorj Azzaya
- Department of Gastroenterology and Hepatology, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (D.A.); (D.D.)
| | - Duger Davaadorj
- Department of Gastroenterology and Hepatology, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (D.A.); (D.D.)
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 879-5593, Oita, Japan; (B.S.); (R.I.A.); (A.K.); (N.R.); (T.M.); (J.A.)
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, East Java, Indonesia
- The Research Center for GLOBAL and LOCAL Infectious Diseases (RCGLID), Oita University, Yufu 870-1192, Oita, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX 77030, USA
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Gibson K, Chu JK, Zhu S, Nguyen D, Mrázek J, Liu J, Hoover TR. A Tripartite Efflux System Affects Flagellum Stability in Helicobacter pylori. Int J Mol Sci 2022; 23:ijms231911609. [PMID: 36232924 PMCID: PMC9570263 DOI: 10.3390/ijms231911609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Helicobacter pylori uses a cluster of polar, sheathed flagella for swimming motility. A search for homologs of H. pylori proteins that were conserved in Helicobacter species that possess flagellar sheaths but were underrepresented in Helicobacter species with unsheathed flagella identified several candidate proteins. Four of the identified proteins are predicted to form part of a tripartite efflux system that includes two transmembrane domains of an ABC transporter (HP1487 and HP1486), a periplasmic membrane fusion protein (HP1488), and a TolC-like outer membrane efflux protein (HP1489). Deleting hp1486/hp1487 and hp1489 homologs in H. pylori B128 resulted in reductions in motility and the number of flagella per cell. Cryo-electron tomography studies of intact motors of the Δhp1489 and Δhp1486/hp1487 mutants revealed many of the cells contained a potential flagellum disassembly product consisting of decorated L and P rings, which has been reported in other bacteria. Aberrant motors lacking specific components, including a cage-like structure that surrounds the motor, were also observed in the Δhp1489 mutant. These findings suggest a role for the H. pylori HP1486-HP1489 tripartite efflux system in flagellum stability. Three independent variants of the Δhp1486/hp1487 mutant with enhanced motility were isolated. All three motile variants had the same frameshift mutation in fliL, suggesting a role for FliL in flagellum disassembly.
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Affiliation(s)
- Katherine Gibson
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Joshua K. Chu
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Shiwei Zhu
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
| | - Doreen Nguyen
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Jan Mrázek
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Jun Liu
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-542-2675
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Clarke KR, Hor L, Pilapitiya A, Luirink J, Paxman JJ, Heras B. Phylogenetic Classification and Functional Review of Autotransporters. Front Immunol 2022; 13:921272. [PMID: 35860281 PMCID: PMC9289746 DOI: 10.3389/fimmu.2022.921272] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/06/2022] [Indexed: 11/30/2022] Open
Abstract
Autotransporters are the core component of a molecular nano-machine that delivers cargo proteins across the outer membrane of Gram-negative bacteria. Part of the type V secretion system, this large family of proteins play a central role in controlling bacterial interactions with their environment by promoting adhesion to surfaces, biofilm formation, host colonization and invasion as well as cytotoxicity and immunomodulation. As such, autotransporters are key facilitators of fitness and pathogenesis and enable co-operation or competition with other bacteria. Recent years have witnessed a dramatic increase in the number of autotransporter sequences reported and a steady rise in functional studies, which further link these proteins to multiple virulence phenotypes. In this review we provide an overview of our current knowledge on classical autotransporter proteins, the archetype of this protein superfamily. We also carry out a phylogenetic analysis of their functional domains and present a new classification system for this exquisitely diverse group of bacterial proteins. The sixteen phylogenetic divisions identified establish sensible relationships between well characterized autotransporters and inform structural and functional predictions of uncharacterized proteins, which may guide future research aimed at addressing multiple unanswered aspects in this group of therapeutically important bacterial factors.
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Affiliation(s)
- Kaitlin R. Clarke
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Lilian Hor
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Akila Pilapitiya
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Joen Luirink
- Department of Molecular Microbiology, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit, Amsterdam, Netherlands
| | - Jason J. Paxman
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
- *Correspondence: Begoña Heras, ; Jason J. Paxman,
| | - Begoña Heras
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
- *Correspondence: Begoña Heras, ; Jason J. Paxman,
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Noble K, Lu J, Guevara MA, Doster RS, Chambers SA, Rogers LM, Moore RE, Spicer SK, Eastman AJ, Francis JD, Manning SD, Rajagopal L, Aronoff DM, Townsend SD, Gaddy JA. Group B Streptococcus cpsE Is Required for Serotype V Capsule Production and Aids in Biofilm Formation and Ascending Infection of the Reproductive Tract during Pregnancy. ACS Infect Dis 2021; 7:2686-2696. [PMID: 34076405 DOI: 10.1021/acsinfecdis.1c00182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Group B Streptococcus (GBS) is an encapsulated Gram-positive pathogen that causes ascending infections of the reproductive tract during pregnancy. The capsule of this organism is a critical virulence factor that has been implicated in a variety of cellular processes to promote pathogenesis. Primarily comprised of carbohydrates, the GBS capsule and its synthesis is driven by the capsule polysaccharide synthesis (cps) operon. The cpsE gene within this operon encodes a putative glycosyltransferase that is responsible for the transfer of a Glc-1-P from UDP-Glc to an undecaprenyl lipid molecule. We hypothesized that the cpsE gene product is important for GBS virulence and ascending infection during pregnancy. Our work demonstrates that a GBS cpsE mutant secretes fewer carbohydrates, has a reduced capsule, and forms less biofilm than the wild-type parental strain. We show that, compared to the parental strain, the ΔcpsE deletion mutant is more readily taken up by human placental macrophages and has a significantly attenuated ability to invade and proliferate in the mouse reproductive tract. Taken together, these results demonstrate that the cpsE gene product is an important virulence factor that aids in GBS colonization and invasion of the gravid reproductive tract.
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Affiliation(s)
- Kristen Noble
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Miriam A. Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Schuyler A. Chambers
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Lisa M. Rogers
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Rebecca E. Moore
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Sabrina K. Spicer
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Alison J. Eastman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jamisha D. Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48823, United States
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington, Seattle, Washington 98109, United States
| | - David M. Aronoff
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Departments of Biochemistry and Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Steven D. Townsend
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jennifer A. Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee 37212, United States
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10
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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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11
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Chu J, Liu J, Hoover TR. Phylogenetic Distribution, Ultrastructure, and Function of Bacterial Flagellar Sheaths. Biomolecules 2020; 10:biom10030363. [PMID: 32120823 PMCID: PMC7175336 DOI: 10.3390/biom10030363] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
A number of Gram-negative bacteria have a membrane surrounding their flagella, referred to as the flagellar sheath, which is continuous with the outer membrane. The flagellar sheath was initially described in Vibrio metschnikovii in the early 1950s as an extension of the outer cell wall layer that completely surrounded the flagellar filament. Subsequent studies identified other bacteria that possess flagellar sheaths, most of which are restricted to a few genera of the phylum Proteobacteria. Biochemical analysis of the flagellar sheaths from a few bacterial species revealed the presence of lipopolysaccharide, phospholipids, and outer membrane proteins in the sheath. Some proteins localize preferentially to the flagellar sheath, indicating mechanisms exist for protein partitioning to the sheath. Recent cryo-electron tomography studies have yielded high resolution images of the flagellar sheath and other structures closely associated with the sheath, which has generated insights and new hypotheses for how the flagellar sheath is synthesized. Various functions have been proposed for the flagellar sheath, including preventing disassociation of the flagellin subunits in the presence of gastric acid, avoiding activation of the host innate immune response by flagellin, activating the host immune response, adherence to host cells, and protecting the bacterium from bacteriophages.
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Affiliation(s)
- Joshua Chu
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA;
| | - Jun Liu
- Microbial Sciences Institute, Department of Microbial Pathogenesis, Yale University, West Haven, CT 06516, USA;
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-542-2675
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12
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In silico proteomic and phylogenetic analysis of the outer membrane protein repertoire of gastric Helicobacter species. Sci Rep 2018; 8:15453. [PMID: 30337679 PMCID: PMC6194013 DOI: 10.1038/s41598-018-32476-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 09/03/2018] [Indexed: 12/16/2022] Open
Abstract
Helicobacter (H.) pylori is an important risk factor for gastric malignancies worldwide. Its outer membrane proteome takes an important role in colonization of the human gastric mucosa. However, in zoonotic non-H. pylori helicobacters (NHPHs) also associated with human gastric disease, the composition of the outer membrane (OM) proteome and its relative contribution to disease remain largely unknown. By means of a comprehensive survey of the diversity and distribution of predicted outer membrane proteins (OMPs) identified in all known gastric Helicobacter species with fully annotated genome sequences, we found genus- and species-specific families known or thought to be implicated in virulence. Hop adhesins, part of the Helicobacter-specific family 13 (Hop, Hor and Hom) were restricted to the gastric species H. pylori, H. cetorum and H. acinonychis. Hof proteins (family 33) were putative adhesins with predicted Occ- or MOMP-family like 18-stranded β-barrels. They were found to be widespread amongst all gastric Helicobacter species only sporadically detected in enterohepatic Helicobacter species. These latter are other members within the genus Helicobacter, although ecologically and genetically distinct. LpxR, a lipopolysaccharide remodeling factor, was also detected in all gastric Helicobacter species but lacking as well from the enterohepatic species H. cinaedi, H. equorum and H. hepaticus. In conclusion, our systemic survey of Helicobacter OMPs points to species and infection-site specific members that are interesting candidates for future virulence and colonization studies.
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13
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Zheng R, Wu S, Ma N, Sun C. Genetic and Physiological Adaptations of Marine Bacterium Pseudomonas stutzeri 273 to Mercury Stress. Front Microbiol 2018; 9:682. [PMID: 29675016 PMCID: PMC5895735 DOI: 10.3389/fmicb.2018.00682] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/22/2018] [Indexed: 12/18/2022] Open
Abstract
Mercury-mediated toxicity remains one of the greatest barriers against microbial survival, even though bacterial resistance to mercury compounds can occur. However, the genetic and physiological adaptations of bacteria to mercury stress still remains unclear. Here, we show that the marine bacterium Pseudomonas stutzeri 273 is resistant to 50 μM Hg2+ and removes up to 94% Hg2+ from culture. Using gene homologous recombination and complementation, we show that genes encoding Hg2+-transport proteins MerT, MerP, the mercuric reductase MerA and the regulatory protein MerD are essential for bacterial mercuric resistance when challenged with Hg2+. Further, mercury stress inhibits flagellar development, motility, chemotaxis and biofilm formation of P. stutzeri 273, which are verified by transcriptomic and physiological analyses. Surprisingly, we discover that MerF, a previously reported Hg2+-transporter, determines flagellar development, motility and biofilm formation in P. stutzeri 273 by genetic and physiological analyses. Our results strongly indicate that MerF plays an integral role in P. stutzeri 273 to develop physiological responses to mercury stress. Notably, MerF homologs are also prevalent in different human pathogens. Using this unique target may provide novel strategies to control these pathogenic bacteria, given the role of MerF in flagella and biofilm formation. In summary, our data provide an original report on MerF in bacterial physiological development and suggest that the mer in marine bacteria has evolved through progressive, sequential recruitment of novel functions over time.
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Affiliation(s)
- Rikuan Zheng
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shimei Wu
- College of Life Sciences, Qingdao University, Qingdao, China
| | - Ning Ma
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chaomin Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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14
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Isaeva G, Valieva R. Biological characteristics and virulence of Helicobacter pylori. CLINICAL MICROBIOLOGY AND ANTIMICROBIAL CHEMOTHERAPY 2018. [DOI: 10.36488/cmac.2018.1.14-23] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
This review summarizes the most recent data on the biological characteristics of Helicobacter pylori (morphological, cultural, biochemical). H. pylori pathogenicity factors promoting colonization, adhesion, biofilm formation, aggression, and cytotoxicity, their contribution to the pathogenesis of diseases as well as the possible relationships with various clinical outcomes are described in detail. The genetic heterogeneity of H. pylori strains which can determine different clinical manifestations and have significance for conducting epidemiological studies is also considered.
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Affiliation(s)
- G.Sh. Isaeva
- Kazan Research Institute of Epidemiology and Microbiology; Kazan State Medical University (Kazan, Russia)
| | - R.I. Valieva
- Kazan Research Institute of Epidemiology and Microbiology; KazanState Medical University (Kazan, Russia)
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15
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Bangpanwimon K, Sottisuporn J, Mittraparp-Arthorn P, Ueaphatthanaphanich W, Rattanasupar A, Pourcel C, Vuddhakul V. CRISPR-like sequences in Helicobacter pylori and application in genotyping. Gut Pathog 2017; 9:65. [PMID: 29177012 PMCID: PMC5693588 DOI: 10.1186/s13099-017-0215-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 11/06/2017] [Indexed: 02/07/2023] Open
Abstract
Background Many bacteria and archaea possess a defense system called clustered regularly interspaced short palindromic repeats (CRISPR) associated proteins (CRISPR-Cas system) against invaders such as phages or plasmids. This system has not been demonstrated in Helicobacter pylori. The numbers of spacer in CRISPR array differ among bacterial strains and can be used as a genetic marker for bacterial typing. Results A total of 36 H. pylori isolates were collected from patients in three hospitals located in the central (PBH) and southern (SKH) regions of Thailand. It is of interest that CRISPR-like sequences of this bacterium were detected in vlpC encoded for VacA-like protein C. Virulence genes were investigated and the most pathogenic genotype (cagA vacA s1m1) was detected in 17 out of 29 (58.6%) isolates from PBH and 5 out of 7 (71.4%) from SKH. vapD gene was identified in each one isolate from PBH and SKH. CRISPR-like sequences and virulence genes of 20 isolates of H. pylori obtained in this study were analyzed and CRISPR-virulence typing was constructed and compared to profiles obtained by the random amplification of polymorphic DNA (RAPD) technique. The discriminatory power (DI) of CRISPR-virulence typing was not different from RAPD typing. Conclusion CRISPR-virulence typing in H. pylori is easy and reliable for epidemiology and can be used for inter-laboratory interpretation. Electronic supplementary material The online version of this article (10.1186/s13099-017-0215-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Khotchawan Bangpanwimon
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
| | - Jaksin Sottisuporn
- NKC Institute of Gastroenterology and Hepatology, Songklanagarind Hospital, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
| | | | | | - Attapon Rattanasupar
- KC Center of Gastroenterology and Hepatology, Hat Yai Hospital, Hat Yai, Thailand
| | - Christine Pourcel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Varaporn Vuddhakul
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
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16
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Webb CT, Chandrapala D, Oslan SN, Bamert RS, Grinter RD, Dunstan RA, Gorrell RJ, Song J, Strugnell RA, Lithgow T, Kwok T. Reductive evolution in outer membrane protein biogenesis has not compromised cell surface complexity in Helicobacter pylori. Microbiologyopen 2017; 6. [PMID: 29055967 PMCID: PMC5727368 DOI: 10.1002/mbo3.513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/18/2022] Open
Abstract
Helicobacter pylori is a gram‐negative bacterial pathogen that chronically inhabits the human stomach. To survive and maintain advantage, it has evolved unique host–pathogen interactions mediated by Helicobacter‐specific proteins in the bacterial outer membrane. These outer membrane proteins (OMPs) are anchored to the cell surface via a C‐terminal β‐barrel domain, which requires their assembly by the β‐barrel assembly machinery (BAM). Here we have assessed the complexity of the OMP C‐terminal β‐barrel domains employed by H. pylori, and characterized the H. pyloriBAM complex. Around 50 Helicobacter‐specific OMPs were assessed with predictive structural algorithms. The data suggest that H. pylori utilizes a unique β‐barrel architecture that might constitute H. pylori‐specific Type V secretions system. The structural and functional diversity in these proteins is encompassed by their extramembrane domains. Bioinformatic and biochemical characterization suggests that the low β‐barrel‐complexity requires only minimalist assembly machinery. The H. pylori proteins BamA and BamD associate to form a BAM complex, with features of BamA enabling an oligomerization that might represent a mechanism by which a minimalist BAM complex forms a larger, sophisticated machinery capable of servicing the outer membrane proteome of H. pylori.
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Affiliation(s)
- Chaille T. Webb
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Dilini Chandrapala
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of Biochemistry and Molecular BiologyMonash UniversityClaytonAustralia
| | - Siti Nurbaya Oslan
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
- Department of BiochemistryFaculty of Biotechnology and Biomolecular SciencesUniversiti Putra MalaysiaSerdangSelangorMalaysia
- Enzyme and Microbial Technology Research CenterUniversiti Putra MalaysiaSerdangSelangorMalaysia
| | - Rebecca S. Bamert
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Rhys D. Grinter
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Rhys A. Dunstan
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Rebecca J. Gorrell
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of Biochemistry and Molecular BiologyMonash UniversityClaytonAustralia
| | - Jiangning Song
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of Biochemistry and Molecular BiologyMonash UniversityClaytonAustralia
- Monash Centre for Data ScienceFaculty of Information TechnologyMonash UniversityMelbourneAustralia
| | - Richard A. Strugnell
- Department of Microbiology & ImmunologyUniversity of MelbourneParkvilleAustralia
| | - Trevor Lithgow
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Terry Kwok
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of Biochemistry and Molecular BiologyMonash UniversityClaytonAustralia
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17
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Silva B, Nunes A, Vale FF, Rocha R, Gomes JP, Dias R, Oleastro M. The expression of Helicobacter pylori tfs plasticity zone cluster is regulated by pH and adherence, and its composition is associated with differential gastric IL-8 secretion. Helicobacter 2017; 22. [PMID: 28436598 DOI: 10.1111/hel.12390] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Helicobacter pylori virulence is associated with different clinical outcomes. The existence of an intact dupA gene from tfs4b cluster has been suggested as a predictor for duodenal ulcer development. However, the role of tfs plasticity zone clusters in the development of ulcers remains unclear. We studied several H. pylori strains to characterize the gene arrangement of tfs3 and tfs4 clusters and their impact in the inflammatory response by infected gastric cells. METHODS The genome of 14 H. pylori strains isolated from Western patients, pediatric (n=10) and adult (n=4), was fully sequenced using the Illumina platform MiSeq, in addition to eight pediatric strains previously sequenced. These strains were used to infect human gastric cells, and the secreted interleukin-8 (IL-8) was quantified by ELISA. The expression of virB2, dupA, virB8, virB10, and virB6 was assessed by quantitative PCR in adherent and nonadherent fractions of H. pylori during in vitro co-infection, at different pH values. RESULTS We have found that cagA-positive H. pylori strains harboring a complete tfs plasticity zone cluster significantly induce increased production of IL-8 from gastric cells. We have also found that the region spanning from virB2 to virB10 genes constitutes an operon, whose expression is increased in the adherent fraction of bacteria during infection, as well as in both adherent and nonadherent fractions at acidic conditions. CONCLUSIONS A complete tfs plasticity zone cluster is a virulence factor that may be important for the colonization of H. pylori and to the development of severe outcomes of the infection with cagA-positive strains.
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Affiliation(s)
- Bruno Silva
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Filipa F Vale
- Host-Pathogen Interactions Unit, Research Institute for Medicines (iMed-ULisboa), Instituto de Medicina Molecular, Faculdade de Farmácia da Universidade de Lisboa, Lisbon, Portugal
| | - Raquel Rocha
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Ricardo Dias
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Mónica Oleastro
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
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18
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Gu H. Role of Flagella in the Pathogenesis of Helicobacter pylori. Curr Microbiol 2017; 74:863-869. [PMID: 28444418 PMCID: PMC5447363 DOI: 10.1007/s00284-017-1256-4] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 04/18/2017] [Indexed: 12/15/2022]
Abstract
This review aimed to investigate the role of Helicobacter pylori flagella on the pathogenicity of this bacterium in humans. Helicobacter pylori is a flagellated pathogen that colonizes the human gastroduodenal mucosa and produces inflammation, and is responsible for gastrointestinal disease. Its pathogenesis is attributed to colonization and virulence factors. The primary function of H. pylori flagella is to provide motility. We believe that H. pylori flagella play an important role in the colonization of the gastrointestinal mucosa. Therefore, we reviewed previous studies on flagellar morphology and motility in order to explore the relationship between H. pylori flagella and pathogenicity. Further investigation is required to confirm the association between flagella and pathogenicity in H. pylori.
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Affiliation(s)
- Haiying Gu
- Medical School, Ningbo University, Ningbo, 315211, China.
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19
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The Helicobacter pylori Autotransporter ImaA Tempers the Bacterium's Interaction with α5β1 Integrin. Infect Immun 2016; 85:IAI.00450-16. [PMID: 27795352 DOI: 10.1128/iai.00450-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/07/2016] [Indexed: 02/07/2023] Open
Abstract
The human pathogen Helicobacter pylori uses the host receptor α5β1 integrin to trigger inflammation in host cells via its cag pathogenicity island (cag PAI) type IV secretion system (T4SS). Here, we report that the H. pylori ImaA protein (HP0289) decreases the action of the cag PAI T4SS via tempering the bacterium's interaction with α5β1 integrin. Previously, imaA-null mutants were found to induce an elevated inflammatory response that was dependent on the cag PAI T4SS; here we extend those findings to show that the elevated response is independent of the CagA effector protein. To understand how ImaA could be affecting cag PAI T4SS activity at the host cell interface, we utilized the Phyre structural threading program and found that ImaA has a region with remote homology to bacterial integrin-binding proteins. This region was required for ImaA function. Unexpectedly, we observed that imaA mutants bound higher levels of α5β1 integrin than wild-type H. pylori, an outcome that required the predicted integrin-binding homology region of ImaA. Lastly, we report that ImaA directly affected the amount of host cell β1 integrin but not other cellular integrins. Our results thus suggest a model in which H. pylori employs ImaA to regulate interactions between integrin and the T4SS and thus alter the host inflammatory strength.
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20
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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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21
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Divergence between the Highly Virulent Zoonotic Pathogen Helicobacter heilmannii and Its Closest Relative, the Low-Virulence "Helicobacter ailurogastricus" sp. nov. Infect Immun 2015; 84:293-306. [PMID: 26527212 DOI: 10.1128/iai.01300-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 10/26/2015] [Indexed: 12/21/2022] Open
Abstract
Helicobacter heilmannii naturally colonizes the stomachs of dogs and cats and has been associated with gastric disorders in humans. Nine feline Helicobacter strains, classified as H. heilmannii based on ureAB and 16S rRNA gene sequences, were divided into a highly virulent and a low-virulence group. The genomes of these strains were sequenced to investigate their phylogenetic relationships, to define their gene content and diversity, and to determine if the differences in pathogenicity were associated with the presence or absence of potential virulence genes. The capacities of these helicobacters to bind to the gastric mucosa were investigated as well. Our analyses revealed that the low-virulence strains do not belong to the species H. heilmannii but to a novel, closely related species for which we propose the name Helicobacter ailurogastricus. Several homologs of H. pylori virulence factors, such as IceA1, HrgA, and jhp0562-like glycosyltransferase, are present in H. heilmannii but absent in H. ailurogastricus. Both species contain a VacA-like autotransporter, for which the passenger domain is remarkably larger in H. ailurogastricus than in H. heilmannii. In addition, H. ailurogastricus shows clear differences in binding to the gastric mucosa compared to H. heilmannii. These findings highlight the low-virulence character of this novel Helicobacter species.
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22
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Guevara C, Zhang C, Gaddy JA, Iqbal J, Guerra J, Greenberg DP, Decker MD, Carbonetti N, Starner TD, McCray PB, Mooi FR, Gómez-Duarte OG. Highly differentiated human airway epithelial cells: a model to study host cell-parasite interactions in pertussis. Infect Dis (Lond) 2015; 48:177-88. [PMID: 26492208 DOI: 10.3109/23744235.2015.1100323] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Bordetella pertussis colonizes the human respiratory mucosa. Most studies on B. pertussis adherence have relied on cultured mammalian cells that lack key features present in differentiated human airway cells or on animal models that are not natural hosts of B. pertussis. The objectives of this work were to evaluate B. pertussis infection in highly differentiated human airway cells in vitro and to show the role of B. pertussis fimbriae in cell adherence. METHODS Primary human airway epithelial (PHAE) cells from human bronchi and a human bronchial epithelial (HBE) cell line were grown in vitro under air-liquid interface conditions. RESULTS PHAE and HBE cells infected with B. pertussis wild-type strain revealed bacterial adherence to the apical surface of cells, bacteria-induced cytoskeleton changes, and cell detachment. Mutations in the major fimbrial subunits Fim2/3 or in the minor fimbrial adhesin subunit FimD affected B. pertussis adherence to predominantly HBE cells. This cell model recapitulates the morphologic features of the human airway infected by B. pertussis and confirms the role of fimbriae in B. pertussis adherence. Furthermore, HBE cells show that fimbrial subunits, and specifically FimD adhesin, are critical in B. pertussis adherence to airway cells. CONCLUSIONS The relevance of this model to study host-parasite interaction in pertussis lies in the striking physiologic and morphologic similarity between the PHAE and HBE cells and the human airway ciliated and goblet cells in vivo. These cells can proliferate in vitro, differentiate, and express the same genetic profile as human respiratory cells in vivo.
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Affiliation(s)
- Claudia Guevara
- a Division of Pediatric Infectious Diseases , Vanderbilt University School of Medicine
| | - Chengxian Zhang
- a Division of Pediatric Infectious Diseases , Vanderbilt University School of Medicine
| | - Jennifer A Gaddy
- b Tennessee Valley Healthcare Systems , Department of Veterans Affairs.,c Division of Infectious Diseases , Vanderbilt University School of Medicine , Nashville , TN
| | - Junaid Iqbal
- a Division of Pediatric Infectious Diseases , Vanderbilt University School of Medicine
| | - Julio Guerra
- a Division of Pediatric Infectious Diseases , Vanderbilt University School of Medicine
| | - David P Greenberg
- d Department of Pediatrics , University of Pittsburgh School of Medicine , Pittsburgh , PA.,e Scientific and Medical Affairs , Sanofi Pasteur , Swiftwater , PA
| | - Michael D Decker
- e Scientific and Medical Affairs , Sanofi Pasteur , Swiftwater , PA.,f Department of Health Policy , Vanderbilt University School of Medicine , Nashville , TN
| | - Nicholas Carbonetti
- g Department of Biological and Biomedical Sciences, Department of Microbiology and Immunology , University of Maryland School of Medicine , Baltimore , MD
| | - Timothy D Starner
- h Stead Family Department of Pediatrics , University of Iowa Carver College of Medicine , Iowa City , IA
| | - Paul B McCray
- h Stead Family Department of Pediatrics , University of Iowa Carver College of Medicine , Iowa City , IA
| | - Frits R Mooi
- i National Institute for Public Health and the Environment, Center for Infectious Diseases Control , Bilthoven , The Netherlands
| | - Oscar G Gómez-Duarte
- a Division of Pediatric Infectious Diseases , Vanderbilt University School of Medicine
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23
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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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24
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Noto JM, Lee JY, Gaddy JA, Cover TL, Amieva MR, Peek RM. Regulation of Helicobacter pylori Virulence Within the Context of Iron Deficiency. J Infect Dis 2014; 211:1790-4. [PMID: 25505301 DOI: 10.1093/infdis/jiu805] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/03/2014] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori strains that harbor the oncoprotein CagA increase gastric cancer risk, and this risk is augmented under iron-deficient conditions. We demonstrate here that iron depletion induces coccoid morphology in strains lacking cagA. To evaluate the stability of augmented H. pylori virulence phenotypes stimulated by low-iron conditions, H. pylori isolated from iron-depleted conditions in vivo were serially passaged in vitro. Long-term passage decreased the ability of hypervirulent strains to translocate CagA or induce interleukin 8, indicating that hypervirulent phenotypes stimulated by low-level iron conditions are reversible. Therefore, rectifying iron deficiency may attenuate disease among H. pylori-infected persons with no response to antibiotics.
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Affiliation(s)
| | | | - Jennifer A Gaddy
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Timothy L Cover
- Division of Infectious Diseases, Department of Medicine Department of Pathology, Microbiology, and Immunology Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Manuel R Amieva
- Department of Microbiology and Immunology Department of Pediatrics, Stanford University, Palo Alto, California
| | - Richard M Peek
- Division of Gastroenterology Department of Cancer Biology, Vanderbilt University
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25
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Abstract
Helicobacter pylori relies on multiple colonization and virulence factors to persist in the human stomach for life. In addition, these factors can be modulated and vary to suit the ever-changing environment within the host individual. This article outlines the novel developments in this field of research during the past year, highlighting the cag pathogenicity island, VacA, γ-glutamyl-transpeptidase as well as including recent advances in protein structure, bacteria-host interaction, and the role of stomach microbiota.
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26
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Analysis of surface-exposed outer membrane proteins in Helicobacter pylori. J Bacteriol 2014; 196:2455-71. [PMID: 24769695 DOI: 10.1128/jb.01768-14] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
More than 50 Helicobacter pylori genes are predicted to encode outer membrane proteins (OMPs), but there has been relatively little experimental investigation of the H. pylori cell surface proteome. In this study, we used selective biotinylation to label proteins localized to the surface of H. pylori, along with differential detergent extraction procedures to isolate proteins localized to the outer membrane. Proteins that met multiple criteria for surface-exposed outer membrane localization included known adhesins, as well as Cag proteins required for activity of the cag type IV secretion system, putative lipoproteins, and other proteins not previously recognized as cell surface components. We identified sites of nontryptic cleavage consistent with signal sequence cleavage, as well as C-terminal motifs that may be important for protein localization. A subset of surface-exposed proteins were highly susceptible to proteolysis when intact bacteria were treated with proteinase K. Most Hop and Hom OMPs were susceptible to proteolysis, whereas Hor and Hof proteins were relatively resistant. Most of the protease-susceptible OMPs contain a large protease-susceptible extracellular domain exported beyond the outer membrane and a protease-resistant domain at the C terminus with a predicted β-barrel structure. These features suggest that, similar to the secretion of the VacA passenger domain, the N-terminal domains of protease-susceptible OMPs are exported through an autotransporter pathway. Collectively, these results provide new insights into the repertoire of surface-exposed H. pylori proteins that may mediate bacterium-host interactions, as well as the cell surface topology of these proteins.
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27
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Zanotti G, Cendron L. Structural and functional aspects of the Helicobacter pylori secretome. World J Gastroenterol 2014; 20:1402-1423. [PMID: 24587618 PMCID: PMC3925851 DOI: 10.3748/wjg.v20.i6.1402] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023] Open
Abstract
Proteins secreted by Helicobacter pylori (H. pylori), an important human pathogen responsible for severe gastric diseases, are reviewed from the point of view of their biochemical characterization, both functional and structural. Despite the vast amount of experimental data available on the proteins secreted by this bacterium, the precise size of the secretome remains unknown. In this review, we consider as secreted both proteins that contain a secretion signal for the periplasm and proteins that have been detected in the external medium in in vitro experiments. In this way, H. pylori’s secretome appears to be composed of slightly more than 160 proteins, but this number must be considered very cautiously, not only because the definition of secretome itself is ambiguous but also because the included proteins were observed as secreted in in vitro experiments that were not representative of the environmental situation in vivo. The proteins that appear to be secreted can be grouped into different classes: enzymes (48 proteins), outer membrane proteins (43), components of flagella (11), members of the cytotoxic-associated genes pathogenicity island or other toxins (8 and 5, respectively), binding and transport proteins (9), and others (11). A final group, which includes 28 members, is represented by hypothetical uncharacterized proteins. Despite the large amount of data accumulated on the H. pylori secretome, a considerable amount of work remains to reach a full comprehension of the system at the molecular level.
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