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Bessen DE, Beall BW, Hayes A, Huang W, DiChiara JM, Velusamy S, Tettelin H, Jolley KA, Fallon JT, Chochua S, Alobaidallah MSA, Higgs C, Barnett TC, Steemson JT, Proft T, Davies MR. Recombinational exchange of M-fibril and T-pilus genes generates extensive cell surface diversity in the global group A Streptococcus population. mBio 2024; 15:e0069324. [PMID: 38587426 PMCID: PMC11078000 DOI: 10.1128/mbio.00693-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/09/2024] Open
Abstract
Among genes present in all group A streptococci (GAS), those encoding M-fibril and T-pilus proteins display the highest levels of sequence diversity, giving rise to the two primary serological typing schemes historically used to define strain. A new genotyping scheme for the pilin adhesin and backbone genes is developed and, when combined with emm typing, provides an account of the global GAS strain population. Cluster analysis based on nucleotide sequence similarity assigns most T-serotypes to discrete pilin backbone sequence clusters, yet the established T-types correspond to only half the clusters. The major pilin adhesin and backbone sequence clusters yield 98 unique combinations, defined as "pilin types." Numerous horizontal transfer events that involve pilin or emm genes generate extensive antigenic and functional diversity on the bacterial cell surface and lead to the emergence of new strains. Inferred pilin genotypes applied to a meta-analysis of global population-based collections of pharyngitis and impetigo isolates reveal highly significant associations between pilin genotypes and GAS infection at distinct ecological niches, consistent with a role for pilin gene products in adaptive evolution. Integration of emm and pilin typing into open-access online tools (pubmlst.org) ensures broad utility for end-users wanting to determine the architecture of M-fibril and T-pilus genes from genome assemblies.IMPORTANCEPrecision in defining the variant forms of infectious agents is critical to understanding their population biology and the epidemiology of associated diseases. Group A Streptococcus (GAS) is a global pathogen that causes a wide range of diseases and displays a highly diverse cell surface due to the antigenic heterogeneity of M-fibril and T-pilus proteins which also act as virulence factors of varied functions. emm genotyping is well-established and highly utilized, but there is no counterpart for pilin genes. A global GAS collection provides the basis for a comprehensive pilin typing scheme, and online tools for determining emm and pilin genotypes are developed. Application of these tools reveals the expansion of structural-functional diversity among GAS via horizontal gene transfer, as evidenced by unique combinations of surface protein genes. Pilin and emm genotype correlations with superficial throat vs skin infection provide new insights on the molecular determinants underlying key ecological and epidemiological trends.
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Affiliation(s)
- Debra E. Bessen
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
| | - Bernard W. Beall
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA
- Eagle Global Scientific, LLC, Atlanta, Georgia, USA
| | - Andrew Hayes
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Weihua Huang
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
- Department of Pathology, Brody School of Medicine, Eastern Carolina University, Greenville, North Carolina, USA
| | - Jeanne M. DiChiara
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
| | - Srinivasan Velusamy
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Keith A. Jolley
- Department of Biology, University of Oxford, Oxford, United Kingdom
| | - John T. Fallon
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
- Department of Pathology, Brody School of Medicine, Eastern Carolina University, Greenville, North Carolina, USA
| | - Sopio Chochua
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA
| | - Mosaed S. A. Alobaidallah
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
| | - Charlie Higgs
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Timothy C. Barnett
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Nedlands, Australia
- Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Nedlands, Australia
| | - John T. Steemson
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Thomas Proft
- School of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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Chang C, Ton-That H, Osipiuk J, Joachimiak A, Das A, Ton-That H. Molecular basis for dual functions in pilus assembly modulated by the lid of a pilus-specific sortase. J Biol Chem 2024:107329. [PMID: 38679328 DOI: 10.1016/j.jbc.2024.107329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 04/19/2024] [Accepted: 04/21/2024] [Indexed: 05/01/2024] Open
Abstract
The biphasic assembly of Gram-positive pili begins with the covalent polymerization of distinct pilins catalyzed by a pilus-specific sortase, followed by the cell wall anchoring of the resulting polymers mediated by the housekeeping sortase. In Actinomyces oris, the pilus-specific sortase SrtC2 not only polymerizes FimA pilins to assemble type 2 fimbriae with CafA at the tip, but it can also act as the anchoring sortase, linking both FimA polymers and SrtC1-catalyzed FimP polymers (type 1 fimbriae) to peptidoglycan when the housekeeping sortase SrtA is inactive. To date, the structure-function determinants governing the unique substrate specificity and dual enzymatic activity of SrtC2 have not been illuminated. Here, we present the crystal structure of SrtC2 solved to 2.10-Å resolution. SrtC2 harbors a canonical sortase fold and a lid typical for class C sortases and additional features specific to SrtC2. Structural, biochemical, and mutational analyses of SrtC2 reveal that the extended lid of SrtC2 modulates its dual activity. Specifically, we demonstrate that the polymerizing activity of SrtC2 is still maintained by alanine-substitution, partial deletion, and replacement of the SrtC2 lid with the SrtC1 lid. Strikingly, pilus incorporation of CafA is significantly reduced by these mutations, leading to compromised polymicrobial interactions mediated by CafA. In a srtA mutant, the partial deletion of the SrtC2 lid reduces surface anchoring of FimP polymers, and the lid-swapping mutation enhances this process, while both mutations diminish surface anchoring of FimA pili. Evidently, the extended lid of SrtC2 enables the enzyme the cell wall-anchoring activity in a substrate-selective fashion.
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Affiliation(s)
- Chungyu Chang
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
| | - HyLam Ton-That
- Department of Chemistry, University of California, Irvine, Irvine, California, USA
| | - Jerzy Osipiuk
- Center for Structural Biology of Infectious Diseases (CSBID), Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, USA; Structural Biology Center, Argonne National Laboratory, Lemont, IL, USA
| | - Andrzej Joachimiak
- Center for Structural Biology of Infectious Diseases (CSBID), Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, USA; Structural Biology Center, Argonne National Laboratory, Lemont, IL, USA; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Asis Das
- Department of Medicine, Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, CT, USA
| | - Hung Ton-That
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA; Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles, California, USA.
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Chang C, Ton-That H, Osipiuk J, Joachimiak A, Das A, Ton-That H. Molecular basis for dual functions in pilus assembly modulated by the lid of a pilus-specific sortase. bioRxiv 2024:2023.11.05.565703. [PMID: 37961287 PMCID: PMC10635155 DOI: 10.1101/2023.11.05.565703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The biphasic assembly of Gram-positive pili begins with the covalent polymerization of distinct pilins catalyzed by a pilus-specific sortase, followed by the cell wall anchoring of the resulting polymers mediated by the housekeeping sortase. In Actinomyces oris , the pilus-specific sortase SrtC2 not only polymerizes FimA pilins to assemble type 2 fimbriae with CafA at the tip, but it can also act as the anchoring sortase, linking both FimA polymers and SrtC1-catalyzed FimP polymers (type 1 fimbriae) to peptidoglycan when the housekeeping sortase SrtA is inactive. To date, the structure-function determinants governing the unique substrate specificity and dual enzymatic activity of SrtC2 have not been illuminated. Here, we present the crystal structure of SrtC2 solved to 2.10-Å resolution. SrtC2 harbors a canonical sortase fold and a lid typical for class C sortases and additional features specific to SrtC2. Structural, biochemical, and mutational analyses of SrtC2 reveal that the extended lid of SrtC2 modulates its dual activity. Specifically, we demonstrate that the polymerizing activity of SrtC2 is still maintained by alanine-substitution, partial deletion, and replacement of the SrtC2 lid with the SrtC1 lid. Strikingly, pilus incorporation of CafA is significantly reduced by these mutations, leading to compromised polymicrobial interactions mediated by CafA. In a srtA mutant, the partial deletion of the SrtC2 lid reduces surface anchoring of FimP polymers, and the lid-swapping mutation enhances this process, while both mutations diminish surface anchoring of FimA pili. Evidently, the extended lid of SrtC2 enables the enzyme the cell wall-anchoring activity in a substrate-selective fashion.
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Takahashi R, J-Khemlani AH, Loh JMS, Radcliff FJ, Proft T, Tsai CJY. Different Group A Streptococcus pili lead to varying proinflammatory cytokine responses and virulence. Immunol Cell Biol 2024; 102:21-33. [PMID: 37795567 DOI: 10.1111/imcb.12692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 10/06/2023]
Abstract
The human pathogen Streptococcus pyogenes, or Group A Streptococcus (GAS), is associated with a variety of diseases ranging from mild skin and soft tissue infections to invasive diseases and immune sequelae such as rheumatic heart disease. We have recently reported that one of the virulence factors of this pathogen, the pilus, has inflammatory properties and strongly stimulates the innate immune system. Here we used a range of nonpathogenic Lactococcus lactis gain-of-function mutants, each expressing one of the major pilus types of GAS, to compare the immune responses generated by various types of fully assembled pili. In vitro assays indicated variability in the inflammatory response induced by different pili, with the fibronectin-binding, collagen-binding, T antigen (FCT)-1-type pilus from GAS serotype M6/T6 inducing significantly stronger cytokine secretion than other pili. Furthermore, we established that the same trend of pili-mediated immune response could be modeled in Galleria mellonella larvae, which possess a similar innate immune system to vertebrates. Counterintuitively, across the panel of pili types examined in this study, we observed a negative correlation between the intensity of the immune response demonstrated in our experiments and the disease severity observed clinically in the GAS strains associated with each pilus type. This observation suggests that pili-mediated inflammation is more likely to promote bacterial clearance instead of causing disruptive damages that intensify pathogenesis. This also indicates that pili may not be the main contributor to the inflammatory symptoms seen in GAS diseases. Rather, the immune-potentiating properties of the pilus components could potentially be exploited as a vaccine adjuvant.
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Affiliation(s)
- Risa Takahashi
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Adrina Hema J-Khemlani
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Jacelyn Mei San Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Fiona Jane Radcliff
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Catherine Jia-Yun Tsai
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
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Raynes JM, Young PG, Lorenz N, Loh JM, McGregor R, Baker EN, Proft T, Moreland NJ. Identification of an immunodominant region on a group A Streptococcus T-antigen reveals temperature-dependent motion in pili. Virulence 2023; 14:2180228. [PMID: 36809931 PMCID: PMC9980535 DOI: 10.1080/21505594.2023.2180228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Group A Streptococcus (GAS) is a globally important pathogen causing a broad range of human diseases. GAS pili are elongated proteins with a backbone comprised repeating T-antigen subunits, which extend from the cell surface and have important roles in adhesion and establishing infection. No GAS vaccines are currently available, but T-antigen-based candidates are in pre-clinical development. This study investigated antibody-T-antigen interactions to gain molecular insight into functional antibody responses to GAS pili. Large, chimeric mouse/human Fab-phage libraries generated from mice vaccinated with the complete T18.1 pilus were screened against recombinant T18.1, a representative two-domain T-antigen. Of the two Fab identified for further characterization, one (designated E3) was cross-reactive and also recognized T3.2 and T13, while the other (H3) was type-specific reacting with only T18.1/T18.2 within a T-antigen panel representative of the major GAS T-types. The epitopes for the two Fab, determined by x-ray crystallography and peptide tiling, overlapped and mapped to the N-terminal region of the T18.1 N-domain. This region is predicted to be buried in the polymerized pilus by the C-domain of the next T-antigen subunit. However, flow cytometry and opsonophagocytic assays showed that these epitopes were accessible in the polymerized pilus at 37°C, though not at lower temperature. This suggests that there is motion within the pilus at physiological temperature, with structural analysis of a covalently linked T18.1 dimer indicating "knee-joint" like bending occurs between T-antigen subunits to expose this immunodominant region. This temperature dependent, mechanistic flexing provides new insight into how antibodies interact with T-antigens during infection.
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Affiliation(s)
- Jeremy M. Raynes
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Paul G. Young
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,School of Biological Sciences, The University of Auckland, Auckland, New Zealand,CONTACT Paul G. Young
| | - Natalie Lorenz
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Jacelyn M.S. Loh
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Reuben McGregor
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Edward N. Baker
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Thomas Proft
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Nicole J. Moreland
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,Nicole J. Moreland
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da Silva TF, Glória RDA, de Sousa TJ, Americo MF, Freitas ADS, Viana MVC, de Jesus LCL, da Silva Prado LC, Daniel N, Ménard O, Cochet MF, Dupont D, Jardin J, Borges AD, Fernandes SOA, Cardoso VN, Brenig B, Ferreira E, Profeta R, Aburjaile FF, de Carvalho RDO, Langella P, Le Loir Y, Cherbuy C, Jan G, Azevedo V, Guédon É. Comprehensive probiogenomics analysis of the commensal Escherichia coli CEC15 as a potential probiotic strain. BMC Microbiol 2023; 23:364. [PMID: 38008714 PMCID: PMC10680302 DOI: 10.1186/s12866-023-03112-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/06/2023] [Indexed: 11/28/2023] Open
Abstract
BACKGROUND Probiotics have gained attention for their potential maintaining gut and immune homeostasis. They have been found to confer protection against pathogen colonization, possess immunomodulatory effects, enhance gut barrier functionality, and mitigate inflammation. However, a thorough understanding of the unique mechanisms of effects triggered by individual strains is necessary to optimize their therapeutic efficacy. Probiogenomics, involving high-throughput techniques, can help identify uncharacterized strains and aid in the rational selection of new probiotics. This study evaluates the potential of the Escherichia coli CEC15 strain as a probiotic through in silico, in vitro, and in vivo analyses, comparing it to the well-known probiotic reference E. coli Nissle 1917. Genomic analysis was conducted to identify traits with potential beneficial activity and to assess the safety of each strain (genomic islands, bacteriocin production, antibiotic resistance, production of proteins involved in host homeostasis, and proteins with adhesive properties). In vitro studies assessed survival in gastrointestinal simulated conditions and adhesion to cultured human intestinal cells. Safety was evaluated in BALB/c mice, monitoring the impact of E. coli consumption on clinical signs, intestinal architecture, intestinal permeability, and fecal microbiota. Additionally, the protective effects of both strains were assessed in a murine model of 5-FU-induced mucositis. RESULTS CEC15 mitigates inflammation, reinforces intestinal barrier, and modulates intestinal microbiota. In silico analysis revealed fewer pathogenicity-related traits in CEC15, when compared to Nissle 1917, with fewer toxin-associated genes and no gene suggesting the production of colibactin (a genotoxic agent). Most predicted antibiotic-resistance genes were neither associated with actual resistance, nor with transposable elements. The genome of CEC15 strain encodes proteins related to stress tolerance and to adhesion, in line with its better survival during digestion and higher adhesion to intestinal cells, when compared to Nissle 1917. Moreover, CEC15 exhibited beneficial effects on mice and their intestinal microbiota, both in healthy animals and against 5FU-induced intestinal mucositis. CONCLUSIONS These findings suggest that the CEC15 strain holds promise as a probiotic, as it could modulate the intestinal microbiota, providing immunomodulatory and anti-inflammatory effects, and reinforcing the intestinal barrier. These findings may have implications for the treatment of gastrointestinal disorders, particularly some forms of diarrhea.
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Affiliation(s)
- Tales Fernando da Silva
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Rafael de Assis Glória
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Thiago Jesus de Sousa
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Monique Ferrary Americo
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Andria Dos Santos Freitas
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Marcus Vinicius Canário Viana
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Luís Cláudio Lima de Jesus
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Nathalie Daniel
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Olivia Ménard
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Marie-Françoise Cochet
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Didier Dupont
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Julien Jardin
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Amanda Dias Borges
- Department of clinical and toxicological analysis, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Simone Odília Antunes Fernandes
- Department of clinical and toxicological analysis, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Valbert Nascimento Cardoso
- Department of clinical and toxicological analysis, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Bertram Brenig
- Department of Molecular Biology of Livestock, Institute of Veterinary Medicine, Georg-August Universität Göttingen, Göttingen, Germany
| | - Enio Ferreira
- Department of general pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Profeta
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Flavia Figueira Aburjaile
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Veterinary school, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Philippe Langella
- Université Paris Saclay, INRAE, AgroParisTech, UMR1319, MICALIS, Jouy-en-Josas, France
| | - Yves Le Loir
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Claire Cherbuy
- Université Paris Saclay, INRAE, AgroParisTech, UMR1319, MICALIS, Jouy-en-Josas, France
| | - Gwénaël Jan
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France
| | - Vasco Azevedo
- Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Éric Guédon
- 1INRAE, Institut Agro, STLO, UMR1253, 65 rue de Saint Brieuc, 35042, Rennes, Cedex, France.
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Takebe K, Suzuki M, Sangawa T, Kreikemeyer B, Yamaguchi M, Uzawa N, Sumitomo T, Kawabata S, Nakata M. Analysis of FctB3 crystal structure and insight into its structural stabilization and pilin linkage mechanisms. Arch Microbiol 2023; 206:4. [PMID: 37994962 DOI: 10.1007/s00203-023-03727-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/23/2023] [Accepted: 10/29/2023] [Indexed: 11/24/2023]
Abstract
Streptococcus pyogenes harboring an FCT type 3 genomic region display pili composed of three types of pilins. In this study, the structure of the base pilin FctB from a serotype M3 strain (FctB3) was determined at 2.8 Å resolution. In accordance with the previously reported structure of FctB from a serotype T9 strain (FctB9), FctB3 was found to consist of an immunoglobulin-like domain and proline-rich tail region. Data obtained from structure comparison revealed main differences in the omega (Ω) loop structure and the proline-rich tail direction. In the Ω loop structure, a differential hydrogen bond network was observed, while the lysine residue responsible for linkage to growing pili was located at the same position in both structures, which indicated that switching of the hydrogen bond network in the Ω loop without changing the lysine position is advantageous for linkage to the backbone pilin FctA. The difference in direction of the proline-rich tail is potentially caused by a single residue located at the root of the proline-rich tail. Also, the FctB3 structure was found to be stabilized by intramolecular large hydrophobic interactions instead of an isopeptide bond. Comparisons of the FctB3 and FctA structures indicated that the FctA structure is more favorable for linkage to FctA. In addition, the heterodimer formation of FctB with Cpa or FctA was shown to be mediated by the putative chaperone SipA. Together, these findings provide an alternative FctB structure as well as insight into the interactions between pilin proteins.
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Grants
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
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Affiliation(s)
- Katsuki Takebe
- Department of Oral and Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
| | - Mamoru Suzuki
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
| | - Takeshi Sangawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, 18057, Rostock, Germany
| | - Masaya Yamaguchi
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Bioinformatics Research Unit, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Bioinformatics Center, Research Institute for Microbial Diseases, Osaka University, 3-1, Yamadaoka, Suita, Osaka, Japan
- Center for Infectious Diseases Education and Research, Osaka University, 2-8, Yamadaoka, Suita, Osaka, Japan
| | - Narikazu Uzawa
- Department of Oral and Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
| | - Tomoko Sumitomo
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Department of Oral Microbiology, Graduate School of Biomedical Sciences, Tokushima University, 3-18-15, Kuramoto-cho, Tokushima, Japan
| | - Shigetada Kawabata
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Center for Infectious Diseases Education and Research, Osaka University, 2-8, Yamadaoka, Suita, Osaka, Japan
| | - Masanobu Nakata
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan.
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
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8
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Nappi F, Avtaar Singh SS, Jitendra V, Fiore A. Bridging Molecular and Clinical Sciences to Achieve the Best Treatment of Enterococcus faecalis Endocarditis. Microorganisms 2023; 11:2604. [PMID: 37894262 PMCID: PMC10609379 DOI: 10.3390/microorganisms11102604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/14/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023] Open
Abstract
Enterococcus faecalis (E. faecalis) is a commensal bacterium that causes various infections in surgical sites, the urinary tract, and blood. The bacterium is becoming a significant concern because it tends to affect the elderly population, which has a high prevalence of undiagnosed degenerative valvular disease and is often subjected to invasive procedures and implanted medical devices. The bacterium's actions are influenced by specific characteristics like pili activity and biofilm formation. This resistance significantly impedes the effectiveness of numerous antibiotic therapies, particularly in cases of endocarditis. While current guidelines recommend antimicrobial therapy, the emergence of resistant strains has introduced complexity in managing these patients, especially with the increasing use of transcatheter therapies for those who are not suitable for surgery. Presentations of the condition are often varied and associated with generalised symptoms, which may pose a diagnostic challenge. We share our encounter with a case study that concerns an octogenarian who had a TAVI valve and developed endocarditis. We also conducted a literature review to identify the essential treatment algorithms for such cases.
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Affiliation(s)
- Francesco Nappi
- Department of Cardiac Surgery, Centre Cardiologique du Nord, 93200 Saint-Denis, France
| | | | - Vikram Jitendra
- Department of Cardiothoracic Surgery, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, UK;
| | - Antonio Fiore
- Department of Cardiac Surgery, Hôpitaux Universitaires Henri Mondor, Assistance Publique-Hôpitaux de Paris, 94000 Creteil, France;
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9
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Miao C, Cui Y, Yan Z, Jiang Y. Pilus of Streptococcus pneumoniae: structure, function and vaccine potential. Front Cell Infect Microbiol 2023; 13:1270848. [PMID: 37799336 PMCID: PMC10548224 DOI: 10.3389/fcimb.2023.1270848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/04/2023] [Indexed: 10/07/2023] Open
Abstract
The pilus is an extracellular structural part that can be detected in some Streptococcus pneumoniae (S. pneumoniae) isolates (type I pili are found in approximately 30% of strains, while type II pili are found in approximately 20%). It is anchored to the cell wall by LPXTG-like motifs on the peptidoglycan. Two kinds of pili have been discovered, namely, pilus-1 and pilus-2. The former is encoded by pilus islet 1 (PI-1) and is a polymer formed by the protein subunits RrgA, RrgB and RrgC. The latter is encoded by pilus islet 2 (PI-2) and is a polymer composed mainly of the structural protein PitB. Although pili are not necessary for the survival of S. pneumoniae, they serve as the structural basis and as virulence factors that mediate the adhesion of bacteria to host cells and play a direct role in promoting the adhesion, colonization and pathogenesis of S. pneumoniae. In addition, as candidate antigens for protein vaccines, pili have promising potential for use in vaccines with combined immunization strategies. Given the current understanding of the pili of S. pneumoniae regarding the genes, proteins, structure, biological function and epidemiological relationship with serotypes, combined with the immunoprotective efficacy of pilins as protein candidates for vaccines, we here systematically describe the research status and prospects of S. pneumoniae pili and provide new ideas for subsequent vaccine research and development.
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Affiliation(s)
- Chenglin Miao
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yali Cui
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Laboratory Medicine, Meishan Women and Children’s Hospital, Alliance Hospital of West China Second University Hospital, Sichuan University, Meishan, Sichuan, China
- Department of Laboratory Medicine, West China Second University Hospital (Tianfu), Sichuan University/Sichuan Provincial Children’s Hospital, Meishan, Sichuan, China
| | - Ziyi Yan
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yongmei Jiang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, China
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10
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Kaci A, Jonassen CM, Skrede S, Sivertsen A, Steinbakk M, Oppegaard O. Genomic epidemiology of Streptococcus dysgalactiae subsp. equisimilis strains causing invasive disease in Norway during 2018. Front Microbiol 2023; 14:1171913. [PMID: 37485526 PMCID: PMC10361778 DOI: 10.3389/fmicb.2023.1171913] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/31/2023] [Indexed: 07/25/2023] Open
Abstract
Background Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging global pathogen, yet the epidemiology and population genetics of SDSE species have not been extensively characterized. Methods We carried out whole genome sequencing to characterize 274 SDSE isolates causing bloodstream infections obtained through national surveillance program in 2018. We conducted multilocus sequence typing (MLST), emm-typing, core genome phylogeny, as well as investigated key features associated with virulence. Moreover, comparison to SDSE from other geographic regions were performed in order to gain more insight in the evolutionary dynamics in SDSE. Results The phylogenetic analysis indicated a substantial diversity of emm-types and sequence types (STs). Briefly, 17 emm-types and 58 STs were identified that formed 10 clonal complexes (CCs). The predominant ST-types were ST20 (20%), ST17 (17%), and ST29 (11%). While CC17 and CC29 clades showed a substantial heterogeneity with well-separated emm-associated subclades, the CC20 clade harboring the stG62647 emm-type was more homogenous and the most prevalent in the present study. Moreover, we observed notable differences in the distribution of clades within Norway, as well as several disseminated CCs and also distinct geographic variations when compared to data from other countries. We also revealed extensive intra-species recombination events involving surface exposed virulence factors, including the emm gene important for phylogenetic profiling. Conclusion Recombination events involving the emm as well as other virulence genes in SDSE, are important mechanisms in shaping the genetic variability in the SDSE population, potentially offering selective advantages to certain lineages. The enhanced phylogenetic resolution offered by whole genome sequencing is necessary to identify and delimitate outbreaks, monitor and properly characterize emerging strains, as well as elucidate bacterial population dynamics.
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Affiliation(s)
- Alba Kaci
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
| | - Christine M. Jonassen
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
- Department of Virology, Norwegian Institute of Public Health, Oslo, Norway
| | - Steinar Skrede
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Audun Sivertsen
- Department of Microbiology, Haukeland University Hospital, Bergen, Norway
| | | | - Martin Steinbakk
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
| | - Oddvar Oppegaard
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
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11
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Khan MA, Amin A, Farid A, Ullah A, Waris A, Shinwari K, Hussain Y, Alsharif KF, Alzahrani KJ, Khan H. Recent Advances in Genomics-Based Approaches for the Development of Intracellular Bacterial Pathogen Vaccines. Pharmaceutics 2022; 15:pharmaceutics15010152. [PMID: 36678781 PMCID: PMC9863128 DOI: 10.3390/pharmaceutics15010152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 01/04/2023] Open
Abstract
Infectious diseases continue to be a leading cause of morbidity and mortality worldwide. The majority of infectious diseases are caused by intracellular pathogenic bacteria (IPB). Historically, conventional vaccination drives have helped control the pathogenesis of intracellular bacteria and the emergence of antimicrobial resistance, saving millions of lives. However, in light of various limitations, many diseases that involve IPB still do not have adequate vaccines. In response to increasing demand for novel vaccine development strategies, a new area of vaccine research emerged following the advent of genomics technology, which changed the paradigm of vaccine development by utilizing the complete genomic data of microorganisms against them. It became possible to identify genes related to disease virulence, genetic patterns linked to disease virulence, as well as the genetic components that supported immunity and favorable vaccine responses. Complete genomic databases, and advancements in transcriptomics, metabolomics, structural genomics, proteomics, immunomics, pan-genomics, synthetic genomics, and population biology have allowed researchers to identify potential vaccine candidates and predict their effects in patients. New vaccines have been created against diseases for which previously there were no vaccines available, and existing vaccines have been improved. This review highlights the key issues and explores the evolution of vaccines. The increasing volume of IPB genomic data, and their application in novel genome-based techniques for vaccine development, were also examined, along with their characteristics, and the opportunities and obstacles involved. Critically, the application of genomics technology has helped researchers rapidly select and evaluate candidate antigens. Novel vaccines capable of addressing the limitations associated with conventional vaccines have been developed and pressing healthcare issues are being addressed.
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Affiliation(s)
- Muhammad Ajmal Khan
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
- Correspondence: (M.A.K.); or (H.K.)
| | - Aftab Amin
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Awais Farid
- Division of Environment and Sustainability, Hong Kong University of Science and Technology, Hong Kong, China
| | - Amin Ullah
- Molecular Virology Laboratory, Department of Microbiology and Biotechnology, Abasyn University, Peshawar 25000, Pakistan
| | - Abdul Waris
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Khyber Shinwari
- Institute of Chemical Engineering, Department Immuno-Chemistry, Ural Federal University, Yekaterinbiurg 620002, Russia
| | - Yaseen Hussain
- Department of Pharmacy, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Khalaf F. Alsharif
- Department of Clinical Laboratory, College of Applied Medical Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Khalid J. Alzahrani
- Department of Clinical Laboratory, College of Applied Medical Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Haroon Khan
- Department of Clinical Laboratory, College of Applied Medical Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
- Correspondence: (M.A.K.); or (H.K.)
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12
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Roshika R, Jain I, Glenaldo T, Sickler T, Musser JM, Sumby P. Characterization of M-Type-Specific Pilus Expression in Group A Streptococcus. J Bacteriol 2022. [PMID: 36286511 PMCID: PMC9664953 DOI: 10.1128/jb.00270-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our ability to characterize how a pathogen infects and causes disease, and consequently our ability to devise approaches to prevent or attenuate such infections, is inhibited by the finding that isolates of a given pathogen often show phenotypic variability, for example, in their ability to adhere to host cells through modulation of cell surface adhesins. Such variability is observed between isolates of group A
Streptococcus
(GAS), and this study investigates the molecular basis for why some GAS isolates produce pili, cell wall-anchored adhesins, in lower abundance than other isolates do.
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13
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Sayeed MA, Paisie T, Alam MT, Ali A, Camilli A, Wrammert J, Khan AI, Qadri F, Salemi M, Morris JG, Nelson EJ. Development of a Monoclonal Antibody to a Vibriophage as a Proxy for Vibrio cholerae Detection. Infect Immun 2022;:e0016122. [PMID: 35862704 DOI: 10.1128/iai.00161-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cholera is an acute watery, diarrheal disease that causes high rates of morbidity and mortality without treatment. Early detection of the etiologic agent of toxigenic Vibrio cholerae is important to mobilize treatment and mitigate outbreaks. Monoclonal antibody (mAb) based rapid diagnostic tests (RDTs) enable early detection in settings without laboratory capacity. However, the odds of an RDT testing positive are reduced by nearly 90% when the common virulent bacteriophage ICP1 is present. We hypothesize that adding a mAb for the common, and specific, virulent bacteriophage ICP1 as a proxy for V. cholerae to an RDT will increase diagnostic sensitivity when virulent ICP1 phage is present. In this study, we used an in-silico approach to identify immunogenic ICP1 protein targets that were conserved across disparate time periods and locations. Specificity of targets to cholera patients with known ICP1 was determined, and specific targets were used to produce mAbs in a murine model. Candidate mAbs to the head protein demonstrated specificity to ICP1 by Enzyme linked immunosorbent assay (ELISA) and an ICP1 phage neutralization assay. The limit of detection of the final mAb candidate for ICP1 phage particles spiked into cholera stool matrix was 8 × 105 PFU by Western blotting analysis. This mAb will be incorporated into a RDT prototype for evaluation in a future diagnostic study to test the guiding hypothesis behind this study.
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14
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Eislmayr K, Bestehorn A, Morelli L, Borroni M, Walle LV, Lamkanfi M, Kovarik P. Nonredundancy of IL-1α and IL-1β is defined by distinct regulation of tissues orchestrating resistance versus tolerance to infection. Sci Adv 2022; 8:eabj7293. [PMID: 35235356 PMCID: PMC8890706 DOI: 10.1126/sciadv.abj7293] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 01/05/2022] [Indexed: 06/08/2023]
Abstract
Interleukin-1α (IL-1α) and IL-1β are inflammatory cytokines with important roles in health and disease. They trigger the same receptor and elicit comparable cellular responses but, for poorly understood reasons, are not redundant in vivo. Here, we decoupled IL-1α and IL-1β functions that drive protective responses against invasive infection with group A Streptococcus. IL-1β was essential for pathogen clearance, hence resistance to infection, by inducing granulocyte colony-stimulating factor at the infection site and establishing emergency granulopoiesis. In contrast, IL-1α governed reprogramming of liver metabolic pathways associated with tolerance to infection. The IL-1α-dominated hepatic regulation corresponded to high IL-1α levels in the liver during infection. Conversely, IL-1β was critical for the regulation of the spleen transcriptome, which correlated with ample IL-1β expression in this tissue. The results identify distinct and organ-specific roles of IL-1α versus IL-1β and implicate spatial restriction of their expression and bioavailability during infection as the underlying mechanism.
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Affiliation(s)
- Kevin Eislmayr
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Annika Bestehorn
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Luisa Morelli
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Martina Borroni
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Lieselotte Vande Walle
- Laboratory of Medical Immunology, Department of Internal Medicine and Pediatrics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium
| | - Mohamed Lamkanfi
- Laboratory of Medical Immunology, Department of Internal Medicine and Pediatrics, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium
| | - Pavel Kovarik
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
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15
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Takahashi R, Radcliff FJ, Proft T, Tsai CJ. Pilus proteins from
Streptococcus pyogenes
stimulate innate immune responses through Toll‐like receptor 2. Immunol Cell Biol 2022; 100:174-185. [PMID: 35124861 PMCID: PMC9303359 DOI: 10.1111/imcb.12523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/27/2022] [Accepted: 02/02/2022] [Indexed: 11/28/2022]
Abstract
The group A Streptococcus (GAS) pilus is a long, flexible, hair‐like structure anchored to the cell surface that facilitates the adherence of GAS to host cells, thus playing a critical role in initiating infections. Because of its important role in GAS virulence, the pilus has become an attractive target for vaccine development. While current research mainly focuses on pilus function and its potential as a vaccine component, there is a lack of knowledge on how the host immune system recognizes and responds to this abundant surface structure. Here we show that both assembled GAS pili and individual pilus proteins induce a potent release of the proinflammatory cytokines tumor necrosis factor and interleukin‐8. We further show that the surface‐exposed backbone pilin and ancillary pilin 1 subunits are Toll‐like receptor 2 (TLR2) agonists. Using reporter cell lines coexpressing human TLR2 in combination with either TLR1 or TLR6, we determined that activation was mediated by the TLR2/TLR6 heterodimer. Finally, we used solid‐phase and flow cytometry binding assays to illustrate a direct interaction between the pilus subunits and TLR2. These results provide further support for the suitability of the pilus as a vaccine component and opens potential avenues for using GAS pili as an adjuvant or immune‐modulation agent.
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Affiliation(s)
- Risa Takahashi
- Department of Molecular Medicine and Pathology, School of Medical Sciences The University of Auckland Auckland New Zealand
| | - Fiona J Radcliff
- Department of Molecular Medicine and Pathology, School of Medical Sciences The University of Auckland Auckland New Zealand
- Maurice Wilkins Centre for Biomolecular Discoveries The University of Auckland Auckland New Zealand
| | - Thomas Proft
- Department of Molecular Medicine and Pathology, School of Medical Sciences The University of Auckland Auckland New Zealand
- Maurice Wilkins Centre for Biomolecular Discoveries The University of Auckland Auckland New Zealand
| | - Catherine J‐Y Tsai
- Department of Molecular Medicine and Pathology, School of Medical Sciences The University of Auckland Auckland New Zealand
- Maurice Wilkins Centre for Biomolecular Discoveries The University of Auckland Auckland New Zealand
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16
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Mahmoud A, Toth I, Stephenson R. Developing an Effective Glycan‐Based Vaccine for
Streptococcus Pyogenes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Asmaa Mahmoud
- School of Chemistry and Molecular Biosciences The University of Queensland St Lucia Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences The University of Queensland Woolloongabba Australia
- School of Pharmacy The Universitry of Queensland St Lucia Australia
- Institue for Molecular Biosciences The University of Queensland St Lucia Australia
| | - Rachel Stephenson
- School of Chemistry and Molecular Biosciences The University of Queensland St Lucia Australia
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17
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Mahmoud A, Toth I, Stephenson R. Developing an Effective Glycan-based Vaccine for Streptococcus Pyogenes. Angew Chem Int Ed Engl 2021; 61:e202115342. [PMID: 34935243 DOI: 10.1002/anie.202115342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Indexed: 11/11/2022]
Abstract
Streptococcus pyogenes is a primary infective agent that causes approximately 700 million human infections each year, resulting in more than 500,000 deaths. Carbohydrate-based vaccines are proven to be one of the most promising subunit vaccine candidates, as the bacterial glycan pattern(s) are different from mammalian cells and show increased pathogen serotype conservancy than the protein components. In this review we highlight reverse vaccinology for use in the development of subunit vaccines against S. pyogenes, and report reproducible methods of carbohydrate antigen production, in addition to the structure-immunogenicity correlation between group A carbohydrate epitopes and alternative vaccine antigen carrier systems. We also report recent advances used to overcome hurdles in carbohydrate-based vaccine development.
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Affiliation(s)
- Asmaa Mahmoud
- The University of Queensland - Saint Lucia Campus: The University of Queensland, School of Chemistry and Molecular Biosciences, AUSTRALIA
| | - Istvan Toth
- The University of Queensland - Saint Lucia Campus: The University of Queensland, School of Chemistry and Molecular Biosciences, AUSTRALIA
| | - Rachel Stephenson
- The University of Queensland, School of Chemistry and Molecular Biosciences, The University of Queensland, 4068, Brisbane, AUSTRALIA
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18
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Isaka M, Okamoto A, Miura Y, Tatsuno I, Maeyama JI, Hasegawa T. Streptococcus pyogenes TrxSR Two-Component System Regulates Biofilm Production in Acidic Environments. Infect Immun 2021; 89:e0036021. [PMID: 34424754 DOI: 10.1128/IAI.00360-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Bacteria form biofilms for their protection against environmental stress and produce virulence factors within the biofilm. Biofilm formation in acidified environments is regulated by a two-component system, as shown by studies on isogenic mutants of the sensor protein of the two-component regulatory system in Streptococcus pyogenes. In this study, we found that the LiaS histidine kinase sensor mediates biofilm production and pilus expression in an acidified environment through glucose fermentation. The liaS isogenic mutant produced biofilms in a culture acidified by hydrochloric acid but not glucose, suggesting that the acidified environment is sensed by another protein. In addition, the trxS isogenic mutant could not produce biofilms or activate the mga promoter in an acidified environment. Mass spectrometry analysis showed that TrxS regulates M protein, consistent with the transcriptional regulation of emm, which encodes M protein. Our results demonstrate that biofilm production during environmental acidification is directly under the control of TrxS.
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19
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Blanchett S, Tsai CJ, Sandford S, Loh JM, Huang L, Kirman JR, Proft T. Intranasal immunization with Ag85B peptide 25 displayed on Lactococcus lactis using the PilVax platform induces antigen-specific B- and T-cell responses. Immunol Cell Biol 2021; 99:767-781. [PMID: 33866609 DOI: 10.1111/imcb.12462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/27/2021] [Accepted: 04/15/2021] [Indexed: 12/19/2022]
Abstract
Mycobacterium tuberculosis (Mtb) remains a global epidemic despite the widespread use of Bacillus Calmette-Guérin (BCG). Consequently, novel vaccines are required to facilitate a reduction in Mtb morbidity and mortality. PilVax is a peptide delivery strategy for the generation of highly specific mucosal immune responses and is based on the food-grade bacterium Lactococcus lactis that is used to express selected peptides engineered within the Streptococcus pyogenes M1T1 pilus, allowing for peptide amplification, stabilization and enhanced immunogenicity. In the present study, the dominant T-cell epitope from the Mtb protein Ag85B was genetically engineered into the pilus backbone subunit and expressed on the surface of L. lactis. Western blot and flow cytometry confirmed formation of pilus containing the peptide DNA sequence. B-cell responses in intranasally vaccinated mice were analyzed by ELISA while T-cell responses were analyzed by flow cytometry. Serum titers of peptide-specific immunoglobulin (Ig) G and IgA were detected, confirming that vaccination produced antibodies against the cognate peptide. Peptide-specific IgA was also detected across several mucosal sites sampled. Peptide-specific CD4+ T cells were detected at levels similar to those of mice immunized with BCG. PilVax immunization resulted in an unexpected increase in the numbers of CD3+ CD4- CD8- [double negative (DN)] T cells in the lungs of vaccinated mice. Analysis of cytokine production following stimulation with the cognate peptide showed the major cytokine producing cells to be CD4+ T cells and DN T cells. This study provides insight into the antibody and peptide-specific cellular immune responses generated by PilVax vaccination and demonstrates the suitability of this vaccine for conducting a protection study.
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Affiliation(s)
- Samuel Blanchett
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Catherine Jy Tsai
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
| | - Sarah Sandford
- Department of Microbiology & Immunology, University of Otago, Dunedin, New Zealand
| | - Jacelyn Ms Loh
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
| | - Lucy Huang
- Department of Microbiology & Immunology, University of Otago, Dunedin, New Zealand
| | - Joanna R Kirman
- Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand.,Department of Microbiology & Immunology, University of Otago, Dunedin, New Zealand
| | - Thomas Proft
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
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20
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Loh JMS, Rivera-Hernandez T, McGregor R, Khemlani AHJ, Tay ML, Cork AJ, M Raynes J, Moreland NJ, Walker MJ, Proft T. A multivalent T-antigen-based vaccine for Group A Streptococcus. Sci Rep 2021; 11:4353. [PMID: 33623073 PMCID: PMC7902606 DOI: 10.1038/s41598-021-83673-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/19/2021] [Indexed: 11/23/2022] Open
Abstract
Pili of Group A Streptococcus (GAS) are surface-exposed structures involved in adhesion and colonisation of the host during infection. The major protein component of the GAS pilus is the T-antigen, which multimerises to form the pilus shaft. There are currently no licenced vaccines against GAS infections and the T-antigen represents an attractive target for vaccination. We have generated a multivalent vaccine called TeeVax1, a recombinant protein that consists of a fusion of six T-antigen domains. Vaccination with TeeVax1 produces opsonophagocytic antibodies in rabbits and confers protective efficacy in mice against invasive disease. Two further recombinant proteins, TeeVax2 and TeeVax3 were constructed to cover 12 additional T-antigens. Combining TeeVax1–3 produced a robust antibody response in rabbits that was cross-reactive to a full panel of 21 T-antigens, expected to provide over 95% vaccine coverage. These results demonstrate the potential for a T-antigen-based vaccine to prevent GAS infections.
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Affiliation(s)
- Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
| | - Tania Rivera-Hernandez
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia.,Cátedras CONACYT-Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Reuben McGregor
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Adrina Hema J Khemlani
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Mei Lin Tay
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Amanda J Cork
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Jeremy M Raynes
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.,Monash University, Clayton Campus, Melbourne, VIC, Australia
| | - Nicole J Moreland
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
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21
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Abstract
Streptococcus pyogenes (Group A Streptococcus; GAS) is an exclusively human pathogen. This bacterial species is responsible for a large variety of infections, ranging from purulent but mostly self-limiting oropharynx/skin diseases to streptococcal sequelae, including glomerulonephritis and rheumatic fever, as well as life-threatening streptococcal toxic-shock syndrome. GAS displays a wide array of surface proteins, with antigenicity of the M protein and pili utilized for M- and T-serotyping, respectively. Since the discovery of GAS pili in 2005, their genetic features, including regulation of expression, and structural features, including assembly mechanisms and protein conformation, as well as their functional role in GAS pathogenesis have been intensively examined. Moreover, their potential as vaccine antigens has been studied in detail. Pilus biogenesis-related genes are located in a discrete section of the GAS genome encoding fibronectin and collagen binding proteins and trypsin-resistant antigens (FCT region). Based on the heterogeneity of genetic composition and DNA sequences, this region is currently classified into nine distinguishable forms. Pili and fibronectin-binding proteins encoded in the FCT region are known to be correlated with infection sites, such as the skin and throat, possibly contributing to tissue tropism. As also found for pili of other Gram-positive bacterial pathogens, GAS pilin proteins polymerize via isopeptide bonds, while intramolecular isopeptide bonds present in the pilin provide increased resistance to degradation by proteases. As supported by findings showing that the main subunit is primarily responsible for T-serotyping antigenicity, pilus functions and gene expression modes are divergent. GAS pili serve as adhesins for tonsillar tissues and keratinocyte cell lines. Of note, a minor subunit is considered to have a harpoon function by which covalent thioester bonds with host ligands are formed. Additionally, GAS pili participate in biofilm formation and evasion of the immune system in a serotype/strain-specific manner. These multiple functions highlight crucial roles of pili during the onset of GAS infection. This review summarizes the current state of the art regarding GAS pili, including a new mode of host-GAS interaction mediated by pili, along with insights into pilus expression in terms of tissue tropism.
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Affiliation(s)
- Masanobu Nakata
- Department of Oral Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, Germany
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22
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Alves-Barroco C, Paquete-Ferreira J, Santos-Silva T, Fernandes AR. Singularities of Pyogenic Streptococcal Biofilms - From Formation to Health Implication. Front Microbiol 2021; 11:584947. [PMID: 33424785 PMCID: PMC7785724 DOI: 10.3389/fmicb.2020.584947] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/20/2020] [Indexed: 01/09/2023] Open
Abstract
Biofilms are generally defined as communities of cells involved in a self-produced extracellular matrix adhered to a surface. In biofilms, the bacteria are less sensitive to host defense mechanisms and antimicrobial agents, due to multiple strategies, that involve modulation of gene expression, controlled metabolic rate, intercellular communication, composition, and 3D architecture of the extracellular matrix. These factors play a key role in streptococci pathogenesis, contributing to therapy failure and promoting persistent infections. The species of the pyogenic group together with Streptococcus pneumoniae are the major pathogens belonging the genus Streptococcus, and its biofilm growth has been investigated, but insights in the genetic origin of biofilm formation are limited. This review summarizes pyogenic streptococci biofilms with details on constitution, formation, and virulence factors associated with formation.
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Affiliation(s)
- Cinthia Alves-Barroco
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - João Paquete-Ferreira
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Teresa Santos-Silva
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Alexandra R Fernandes
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
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23
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Yadav P, Verma S, Bauer R, Kumari M, Dua M, Johri AK, Yadav V, Spellerberg B. Deciphering Streptococcal Biofilms. Microorganisms 2020; 8:E1835. [PMID: 33233415 DOI: 10.3390/microorganisms8111835] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/10/2020] [Accepted: 11/17/2020] [Indexed: 12/19/2022] Open
Abstract
Streptococci are a diverse group of bacteria, which are mostly commensals but also cause a considerable proportion of life-threatening infections. They colonize many different host niches such as the oral cavity, the respiratory, gastrointestinal, and urogenital tract. While these host compartments impose different environmental conditions, many streptococci form biofilms on mucosal membranes facilitating their prolonged survival. In response to environmental conditions or stimuli, bacteria experience profound physiologic and metabolic changes during biofilm formation. While investigating bacterial cells under planktonic and biofilm conditions, various genes have been identified that are important for the initial step of biofilm formation. Expression patterns of these genes during the transition from planktonic to biofilm growth suggest a highly regulated and complex process. Biofilms as a bacterial survival strategy allow evasion of host immunity and protection against antibiotic therapy. However, the exact mechanisms by which biofilm-associated bacteria cause disease are poorly understood. Therefore, advanced molecular techniques are employed to identify gene(s) or protein(s) as targets for the development of antibiofilm therapeutic approaches. We review our current understanding of biofilm formation in different streptococci and how biofilm production may alter virulence-associated characteristics of these species. In addition, we have summarized the role of surface proteins especially pili proteins in biofilm formation. This review will provide an overview of strategies which may be exploited for developing novel approaches against biofilm-related streptococcal infections.
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Jespersen MG, Lacey JA, Tong SYC, Davies MR. Global genomic epidemiology of Streptococcus pyogenes. Infect Genet Evol 2020; 86:104609. [PMID: 33147506 DOI: 10.1016/j.meegid.2020.104609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 02/04/2023]
Abstract
Streptococcus pyogenes is one of the Top 10 human infectious disease killers worldwide causing a range of clinical manifestations in humans. Colonizing a range of ecological niches within its sole host, the human, is key to the ability of this opportunistic pathogen to cause direct and post-infectious manifestations. The expansion of genome sequencing capabilities and data availability over the last decade has led to an improved understanding of the evolutionary dynamics of this pathogen within a global framework where epidemiological relationships and evolutionary mechanisms may not be universal. This review uses the recent publication by Davies et al., 2019 as an updated global framework to address S. pyogenes population genomics, highlighting how genomics is being used to gain new insights into evolutionary processes, transmission pathways, and vaccine design.
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Affiliation(s)
- Magnus G Jespersen
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Jake A Lacey
- Doherty Department, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Steven Y C Tong
- Doherty Department, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia; Victorian Infectious Diseases Service, The Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, VIC, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
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Shoji M, Shibata S, Sueyoshi T, Naito M, Nakayama K. Biogenesis of Type V pili. Microbiol Immunol 2020; 64:643-656. [DOI: 10.1111/1348-0421.12838] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Mikio Shoji
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences Nagasaki University Nagasaki Nagasaki Japan
| | - Satoshi Shibata
- Molecular Cryo‐Electron Microscopy Unit Okinawa Institute of Science and Technology Graduate University Onna Okinawa Japan
| | - Takayuki Sueyoshi
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences Nagasaki University Nagasaki Nagasaki Japan
| | - Mariko Naito
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences Nagasaki University Nagasaki Nagasaki Japan
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences Nagasaki University Nagasaki Nagasaki Japan
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26
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Dzaraly ND, Muthanna A, Mohd Desa MN, Taib NM, Masri SN, Rahman NIA, Suhaili Z, Tuan Soh TS, Abdullah FH. Pilus islets and the clonal spread of piliated Streptococcus pneumoniae: A review. Int J Med Microbiol 2020; 310:151449. [PMID: 33092697 DOI: 10.1016/j.ijmm.2020.151449] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 08/17/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
Pneumococci are a common cause of severe infections, such as otitis media, pneumonia, meningitis and bacteremia. Pili are detected in a small proportion of pneumococcal population, but these structures have recently been associated with bacterial virulence in humans. Therefore, the epidemiological relationships between pneumococcal pili, serotype and antimicrobial resistance are of interest. This study aims to discuss the virulence contribution of the Streptococcus pneumoniae pili and the epidemiological relationships among the pilus genes, antimicrobial resistance trends, regional serotypes and genotypic variations. Previous reports have characterized the pneumococcal pilus islet as a clonal feature in the pneumococcal serotypes that are covered by the pneumococcal conjugate vaccine (PCV), including serotypes 19A, 19F, 23F and 7F. Many of the pneumococcal molecular epidemiology network (PMEN) clones are piliated isolates that are also strongly associated with a high frequency of multidrug resistance. Most of these piliated pneumococcal isolates belong to a few clonal complexes (CC), such as CC320, CC199, CC271, CC191 and CC156. Additional molecular epidemiology and genomic studies, particularly whole genome sequence analysis (WGS), are needed to develop an in-depth understanding of the piliated pneumococcal isolates.
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Affiliation(s)
- Nurul Diana Dzaraly
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - AbdulRahman Muthanna
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Mohd Nasir Mohd Desa
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
| | - Niazlin Mohd Taib
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Siti Norbaya Masri
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Nor Iza A Rahman
- Faculty of Medicine, Universiti Sultan Zainal Abidin, 21400, Kuala Terengganu, Terengganu, Malaysia
| | - Zarizal Suhaili
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; School of Animal Sciences, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut Campus, 22200, Besut, Terengganu, Malaysia; East Coast Environmental Research Institute, Universiti Sultan Zainal Abidin, Gong Badak Campus, 21300, Kuala Terengganu, Terengganu, Malaysia
| | - Tuan Suhaila Tuan Soh
- Department of Pathology, Sungai Buloh Hospital, Jalan Hospital, 47000, Sungai Buloh, Selangor, Malaysia
| | - Fatimah Haslina Abdullah
- Department of Pathology, Sultanah Nur Zahirah Hospital, Jalan Sultan Mahmud, 20400, Kuala Terengganu, Terengganu, Malaysia
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Chen YH, Li SH, Yang YC, Hsu SH, Nizet V, Chang YC. T4 Pili Promote Colonization and Immune Evasion Phenotypes of Nonencapsulated M4 Streptococcus pyogenes. mBio 2020; 11:e01580-20. [PMID: 32694142 DOI: 10.1128/mBio.01580-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Streptococcus pyogenes (group A Streptococcus [GAS]) is an important human pathogen causing a broad spectrum of diseases and associated with significant global morbidity and mortality. Almost all GAS isolates express a surface hyaluronic acid capsule, a virulence determinant that facilitates host colonization and impedes phagocyte killing. However, recent epidemiologic surveillance has reported a sustained increase in both mucosal and invasive infections caused by nonencapsulated GAS, which questions the indispensable role of hyaluronic acid capsule in GAS pathogenesis. In this study, we found that pilus of M4 GAS not only significantly promotes biofilm formation, adherence, and cytotoxicity to human upper respiratory tract epithelial cells and keratinocytes, but also promotes survival in human whole blood and increased virulence in murine models of invasive infection. T4 antigen, the pilus backbone protein of M4 GAS, binds haptoglobin, an abundant human acute-phase protein upregulated upon infection and inflammation, on the bacterial surface. Haptoglobin sequestration reduces the susceptibility of nonencapsulated M4 GAS to antimicrobial peptides released from activated neutrophils and platelets. Our results reveal a previously unappreciated virulence-promoting role of M4 GAS pili, in part mediated by co-opting the biology of haptoglobin to mitigate host antimicrobial defenses.IMPORTANCE Group A Streptococcus (GAS) is a strict human pathogen causing more than 700 million infections globally each year. The majority of the disease-causing GAS are encapsulated, which greatly guarantees survival and dissemination in the host. Emergence of the capsule-negative GAS, such as M4 GAS, in recent epidemiologic surveillance alarms the necessity to elucidate the virulence determinants of these pathogens. Here, we found that M4 pili play an important role in promoting M4 GAS adherence and cytotoxicity to human pharyngeal epithelial cells and keratinocytes. The same molecule also significantly enhanced M4 GAS survival and replication in human whole blood and experimental murine infection. T4 antigen, which composes the backbone of M4 pili, was able to sequester the very abundant serum protein haptoglobin to further confer M4 GAS resistance to antibacterial substances released by neutrophils and platelets.
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Prados de la Torre E, Rodríguez-Franco A, Rodríguez-Ortega MJ. Proteomic and Bioinformatic Analysis of Streptococcus suis Human Isolates: Combined Prediction of Potential Vaccine Candidates. Vaccines (Basel) 2020; 8:E188. [PMID: 32325736 DOI: 10.3390/vaccines8020188] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/15/2022] Open
Abstract
Streptococcus suis is a Gram-positive bacterium responsible for major infections in pigs and economic losses in the livestock industry, but also an emerging zoonotic pathogen causing serious diseases in humans. No vaccine is available so far against this microorganism. Conserved surface proteins are among the most promising candidates for new and effective vaccines. Until now, research on this pathogen has focused on swine isolates, but there is a lack of studies to identify and characterize surface proteins from human clinical isolates. In this work, we performed a comparative proteomic analysis of six clinical isolates from human patients, all belonging to the major serotype 2, by “shaving” the live bacterial cells with trypsin, followed by LC-MS/MS analysis. We identified 131 predicted surface proteins and carried out a label-free semi-quantitative analysis of protein abundances within the six strains. Then, we combined our proteomics results with bioinformatic tools to help improving the selection of novel antigens that can enter the pipeline of vaccine candidate testing. Our work is then a complement to the reverse vaccinology concept.
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Abstract
Streptococcal pharyngitis (or strep throat) is a common childhood disease affecting millions of children each year, but it is one of the only childhood diseases for which a vaccine does not exist. While for decades the development of a vaccine has been the center of attention in many laboratories worldwide, with some successes, no corporate development has yet to be initiated. The reason for this probably lies in our inability to conclusively identify the streptococcal molecule or molecules responsible for the heart cross-reactive antibodies observed in the serum of rheumatic fever patients. Without this specific knowledge, any streptococcal vaccine antigen is suspect and thus not the target for a billion-dollar investment, despite the fact that the exact role of cross-reactive antibodies in rheumatic fever is still questionable. This article will describe the development of several approaches to protect against Streptococcus pyogenes infections over the past several decades.
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Nakata M, Sumitomo T, Patenge N, Kreikemeyer B, Kawabata S. Thermosensitive pilus production by FCT type 3 Streptococcus pyogenes controlled by Nra regulator translational efficiency. Mol Microbiol 2019; 113:173-189. [PMID: 31633834 PMCID: PMC7079067 DOI: 10.1111/mmi.14408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2019] [Indexed: 01/18/2023]
Abstract
Streptococcus pyogenes produces a diverse variety of pili in a serotype‐dependent manner and thermosensitive expression of pilus biogenesis genes was previously observed in a serotype M49 strain. However, the precise mechanism and biological significance remain unclear. Herein, the pilus expression analysis revealed the thermosensitive pilus production only in strains possessing the transcriptional regulator Nra. Experimental data obtained for nra deletion and conditional nra‐expressing strains in the background of an M49 strain and the Lactococcus heterologous expression system, indicated that Nra is a positive regulator of pilus genes and also highlighted the importance of the level of intracellular Nra for the thermoregulation of pilus expression. While the nra mRNA level was not significantly influenced by a temperature shift, the Nra protein level was concomitantly increased when the culture temperature was decreased. Intriguingly, a putative stem‐loop structure within the coding region of nra mRNA was a factor related to the post‐transcriptional efficiency of nra mRNA translation. Either deletion of the stem‐loop structure or introduction of silent chromosomal mutations designed to melt the structure attenuated Nra levels, resulting in decreased pilus production. Consequently, the temperature‐dependent translational efficacy of nra mRNA influenced pilus thermoregulation, thereby potentially contributing to the fitness of nra‐positive S. pyogenes in human tissues.
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Affiliation(s)
- Masanobu Nakata
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tomoko Sumitomo
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Nadja Patenge
- Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, D-18057, Germany
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, D-18057, Germany
| | - Shigetada Kawabata
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, 565-0871, Japan
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Hirose Y, Yamaguchi M, Okuzaki D, Motooka D, Hamamoto H, Hanada T, Sumitomo T, Nakata M, Kawabata S. Streptococcus pyogenes Transcriptome Changes in the Inflammatory Environment of Necrotizing Fasciitis. Appl Environ Microbiol 2019; 85:e01428-19. [PMID: 31471300 DOI: 10.1128/AEM.01428-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/23/2019] [Indexed: 12/31/2022] Open
Abstract
Necrotizing fasciitis, a life-threatening subcutaneous soft-tissue infection, is principally caused by S. pyogenes. The inflammatory environment at the site of infection causes global gene expression changes for survival of the bacterium and pathogenesis. However, no known study regarding transcriptomic profiling of S. pyogenes in cases of necrotizing fasciitis has been presented. We identified 483 bacterial genes whose expression was consistently altered during infection. Our results showed that S. pyogenes infection induces drastic upregulation of the expression of virulence-associated genes and shifts metabolic pathway usage. In particular, high-level expression of toxins, such as cytolysins, proteases, and nucleases, was observed at infection sites. In addition, genes identified as consistently enriched included those related to metabolism of arginine and histidine as well as carbohydrate uptake and utilization. Conversely, genes associated with the oxidative stress response and cell division were consistently downregulated during infection. The present findings provide useful information for establishing novel treatment strategies. Streptococcus pyogenes is a major cause of necrotizing fasciitis, a life-threatening subcutaneous soft-tissue infection. At the host infection site, the local environment and interactions between the host and bacteria have effects on bacterial gene expression profiles, while the gene expression pattern of S. pyogenes related to this disease remains unknown. In this study, we used a mouse model of necrotizing fasciitis and performed RNA-sequencing (RNA-seq) analysis of S. pyogenes M1T1 strain 5448 by isolating total RNA from infected hind limbs obtained at 24, 48, and 96 h postinfection. RNA-seq analysis results identified 483 bacterial genes whose expression was consistently altered in the infected hindlimbs compared to their expression under in vitro conditions. Genes showing consistent enrichment during infection included 306 encoding molecules involved in virulence, carbohydrate utilization, amino acid metabolism, trace-metal transport, and the vacuolar ATPase transport system. Surprisingly, drastic upregulation of 3 genes, encoding streptolysin S precursor (sagA), cysteine protease (speB), and secreted DNase (spd), was noted in the present mouse model (log2 fold change, >6.0, >9.4, and >7.1, respectively). Conversely, the number of consistently downregulated genes was 177, including those associated with the oxidative stress response and cell division. These results suggest that in necrotizing fasciitis, S. pyogenes shows an altered metabolism, decreased cell proliferation, and upregulation of expression of major toxins. Our findings are considered to provide critical information for developing novel treatment strategies and vaccines for necrotizing fasciitis. IMPORTANCE Necrotizing fasciitis, a life-threatening subcutaneous soft-tissue infection, is principally caused by S. pyogenes. The inflammatory environment at the site of infection causes global gene expression changes for survival of the bacterium and pathogenesis. However, no known study regarding transcriptomic profiling of S. pyogenes in cases of necrotizing fasciitis has been presented. We identified 483 bacterial genes whose expression was consistently altered during infection. Our results showed that S. pyogenes infection induces drastic upregulation of the expression of virulence-associated genes and shifts metabolic pathway usage. In particular, high-level expression of toxins, such as cytolysins, proteases, and nucleases, was observed at infection sites. In addition, genes identified as consistently enriched included those related to metabolism of arginine and histidine as well as carbohydrate uptake and utilization. Conversely, genes associated with the oxidative stress response and cell division were consistently downregulated during infection. The present findings provide useful information for establishing novel treatment strategies.
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Chang C, Wu C, Osipiuk J, Siegel SD, Zhu S, Liu X, Joachimiak A, Clubb RT, Das A, Ton-That H. Cell-to-cell interaction requires optimal positioning of a pilus tip adhesin modulated by gram-positive transpeptidase enzymes. Proc Natl Acad Sci U S A 2019; 116:18041-18049. [PMID: 31427528 PMCID: PMC6731673 DOI: 10.1073/pnas.1907733116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Assembly of pili on the gram-positive bacterial cell wall involves 2 conserved transpeptidase enzymes named sortases: One for polymerization of pilin subunits and another for anchoring pili to peptidoglycan. How this machine controls pilus length and whether pilus length is critical for cell-to-cell interactions remain unknown. We report here in Actinomyces oris, a key colonizer in the development of oral biofilms, that genetic disruption of its housekeeping sortase SrtA generates exceedingly long pili, catalyzed by its pilus-specific sortase SrtC2 that possesses both pilus polymerization and cell wall anchoring functions. Remarkably, the srtA-deficient mutant fails to mediate interspecies interactions, or coaggregation, even though the coaggregation factor CafA is present at the pilus tip. Increasing ectopic expression of srtA in the mutant progressively shortens pilus length and restores coaggregation accordingly, while elevated levels of shaft pilins and SrtC2 produce long pili and block coaggregation by SrtA+ bacteria. With structural studies, we uncovered 2 key structural elements in SrtA that partake in recognition of pilin substrates and regulate pilus length by inducing the capture and transfer of pilus polymers to the cell wall. Evidently, coaggregation requires proper positioning of the tip adhesin CafA via modulation of pilus length by the housekeeping sortase SrtA.
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Affiliation(s)
- Chungyu Chang
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA 90095;
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030
| | - Jerzy Osipiuk
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL 60637
- Structural Biology Center, Argonne National Laboratory, Lemont, IL 60439
| | - Sara D Siegel
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030
| | - Shiwei Zhu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510
| | - Xiangan Liu
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030
| | - Andrzej Joachimiak
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL 60637
- Structural Biology Center, Argonne National Laboratory, Lemont, IL 60439
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, CA 90095
| | - Asis Das
- Department of Medicine, Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, CT 06030
| | - Hung Ton-That
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA 90095;
- Molecular Biology Institute, University of California, Los Angeles, CA 90095
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Nishiki I, Yoshida T, Fujiwara A. Complete genome sequence and characterization of virulence genes in Lancefield group C Streptococcus dysgalactiae isolated from farmed amberjack (Seriola dumerili). Microbiol Immunol 2019; 63:243-250. [PMID: 31136000 DOI: 10.1111/1348-0421.12716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 01/19/2023]
Abstract
Lancefield group C Streptococcus dysgalactiae causes infections in farmed fish. Here, the genome of S. dysgalactiae strain kdys0611, isolated from farmed amberjack (Seriola dumerili) was sequenced. The complete genome sequence of kdys0611 consists of a single chromosome and five plasmids. The chromosome is 2,142,780 bp long and has a GC content of 40%. It possesses 2061 coding sequences and 67 tRNA and 6 rRNA operons. One clustered regularly interspaced short palindromic repeat, 125 insertion sequences, and four predicted prophage elements were identified. Phylogenetic analysis based on 126 core genes suggested that the kdys0611 strain is more closely related to S. dysgalactiae subsp. dysgalactiae than to S. dysgalactiae subsp. equisimilis. The genome of kdys0611 harbors 87 genes with sequence similarity to putative virulence-associated genes identified in other bacteria, of which 57 exhibit amino acid identity (>52%) to genes of the S. dysgalactiae subsp. equisimilis GGS124 human clinical isolate. Four putative virulence genes, emm5 (FGCSD_0256), spg_2 (FGCSD_1961), skc (FGCSD_1012), and cna (FGCSD_0159), in kdys0611 did not show significant homology with any deposited S. dysgalactiae genes. The chromosomal sequence of kdys0611 has been deposited in GenBank under Accession No. AP018726. This is the first report of the complete genome sequence of S. dysgalactiae isolated from fish.
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Affiliation(s)
- Issei Nishiki
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | | | - Atushi Fujiwara
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
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Young PG, Raynes JM, Loh JM, Proft T, Baker EN, Moreland NJ. Group A Streptococcus T Antigens Have a Highly Conserved Structure Concealed under a Heterogeneous Surface That Has Implications for Vaccine Design. Infect Immun 2019; 87:e00205-19. [PMID: 30936156 DOI: 10.1128/IAI.00205-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 03/25/2019] [Indexed: 12/20/2022] Open
Abstract
Group A Streptococcus (GAS) (Streptococcus pyogenes) is an important human pathogen associated with significant global morbidity and mortality for which there is no safe and efficacious vaccine. The T antigen, a protein that polymerizes to form the backbone of the GAS pilus structure, is a potential vaccine candidate. Previous surveys of the tee gene, which encodes the T antigen, have identified 21 different tee types and subtypes such that any T antigen-based vaccine must be multivalent and carefully designed to provide broad strain coverage. In this study, the crystal structures of three two-domain T antigens (T3.2, T13, and T18.1) were determined and found to have remarkable structural similarity to the previously reported T1 antigen, despite moderate overall sequence similarity. This has enabled reliable modeling of all major two-domain T antigens to reveal that T antigen sequence variation is distributed along the full length of the protein and shields a highly conserved core. Immunoassays performed with sera from immunized animals and commercial T-typing sera identified a significant cross-reactive antibody response between T18.1, T18.2, T3.2, and T13. The existence of shared epitopes between T antigens, combined with the remarkably conserved structure and high level of surface sequence divergence, has important implications for the design of multivalent T antigen-based vaccines.
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Bencardino D, Di Luca MC, Petrelli D, Prenna M, Vitali LA. High virulence gene diversity in Streptococcus pyogenes isolated in Central Italy. PeerJ 2019; 7:e6613. [PMID: 30918759 PMCID: PMC6431245 DOI: 10.7717/peerj.6613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/13/2019] [Indexed: 12/26/2022] Open
Abstract
Globally, Streptococcus pyogenes poses a continuous burden on human health, causing both self-limiting and life-threatening diseases. Therefore, studying the profile of virulence genes and their combinations is essential to monitor the epidemiology and pathogenic potential of this important species. Thus, the aim of this study was to analyze related genetic features of clinical strains collected in Italy in 2012 in order to obtain a valid picture of their virulence profile that could be compared to similar studies made in other countries approximately in the same period. We conducted emm typing and fibronectin-collagen-T antigen (FCT) region typing in 122 Streptococcus pyogenes strains. Furthermore, several additional virulence genes were screened by polymerase chain reaction. We found correlations between emm types and FCT region profiles. emm1 strains were mainly associated with FCT2 and FCT6, while emm89 and emm12 strains were associated with FCT4. FCT5 was mainly represented in emm4, emm6, and emm75 strains. Significantly, we defined subtypes for each FCT type based on the differences in single and double loci compared to the reference scheme used for the classification of the FCT region. In addition, new FCT-region variants with differences in multiple loci were also recorded. Cluster analysis based on virulence gene profiling showed a non-random distribution within each emm type. This study added new data to existing studies conducted worldwide and revealed new variability scores in circulating Streptococcus pyogenes strains and new assortments in well-established virulence gene signatures.
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Affiliation(s)
- Daniela Bencardino
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Maria Chiara Di Luca
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Dezemona Petrelli
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Manuela Prenna
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
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Abstract
The clinico-epidemiological features of diseases caused by group A streptococci (GAS) is presented through the lens of the ecology, population genetics, and evolution of the organism. The serological targets of three typing schemes (M, T, SOF) are themselves GAS cell surface proteins that have a myriad of virulence functions and a diverse array of structural forms. Horizontal gene transfer expands the GAS antigenic cell surface repertoire by generating numerous combinations of M, T, and SOF antigens. However, horizontal gene transfer of the serotype determinant genes is not unconstrained, and therein lies a genetic organization that may signify adaptations to a narrow ecological niche, such as the primary tissue reservoirs of the human host. Adaptations may be further shaped by selection pressures such as herd immunity. Understanding the molecular evolution of GAS on multiple levels-short, intermediate, and long term-sheds insight on mechanisms of host-pathogen interactions, the emergence and spread of new clones, rational vaccine design, and public health interventions.
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Lepp D, Ojha S, Mehdizadeh Gohari I, Chakravarty B, Prescott JF, Gong J. Immunization with subunits of a novel pilus produced by virulent Clostridium perfringens strains confers partial protection against necrotic enteritis in chickens. Vet Microbiol 2019; 230:7-13. [PMID: 30827407 DOI: 10.1016/j.vetmic.2019.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 01/05/2019] [Accepted: 01/06/2019] [Indexed: 11/30/2022]
Abstract
Necrotic enteritis (NE) is an economically important disease of broiler chickens that is caused primarily by Clostridium perfringens strains that produce the NetB toxin. It is controlled in North America principally through the application of in-feed antimicrobials, but alternative control methods, such as vaccination, are urgently needed. We previously identified a cluster of C. perfringens genes prevalent in disease-causing strains, denominated VR-10B, that is predicted to encode a pilus. The current study evaluated the ability of three predicted pilin structural subunits (CnaA, FimA, FimB) to protect against NE in two immunization studies. In the first study, young broiler chickens were immunized twice intramuscularly (i.m.) with CnaA or FimA, which resulted in only a weak serum antibody response, and no reduction in the severity of intestinal lesions following experimental challenge with C. perfringens strain CP1. In the second study, chickens were injected subcutaneously (s.c.) with CnaA, FimB, or a combination of all three proteins, on days 7, 14 and 19, which resulted in a marked antibody response specific to each antigen. Chickens immunized with either CnaA or FimB had significantly reduced NE lesion severity, whereas immunization with all three proteins in combination did not provide protection. Western blot experiments using serum from immunized birds were also performed, providing the first experimental evidence to suggest that this locus may in fact encode a functional pilus structure.
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Affiliation(s)
- D Lepp
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada
| | - S Ojha
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - I Mehdizadeh Gohari
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - B Chakravarty
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada
| | - J F Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - J Gong
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada.
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Rivas-Pardo JA, Badilla CL, Tapia-Rojo R, Alonso-Caballero Á, Fernández JM. Molecular strategy for blocking isopeptide bond formation in nascent pilin proteins. Proc Natl Acad Sci U S A 2018; 115:9222-7. [PMID: 30150415 DOI: 10.1073/pnas.1807689115] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Bacteria anchor to their host cells through their adhesive pili, which must resist the large mechanical stresses induced by the host as it attempts to dislodge the pathogens. The pili of gram-positive bacteria are constructed as a single polypeptide made of hundreds of pilin repeats, which contain intramolecular isopeptide bonds strategically located in the structure to prevent their unfolding under force, protecting the pilus from degradation by extant proteases and oxygen radicals. Here, we demonstrate the design of a short peptide that blocks the formation of the isopeptide bond present in the pilin Spy0128 from the human pathogen Streptococcus pyogenes, resulting in mechanically labile pilin domains. We use a combination of protein engineering and atomic-force microscopy force spectroscopy to demonstrate that the peptide blocks the formation of the native isopeptide bond and compromises the mechanics of the domain. While an intact Spy0128 is inextensible at any force, peptide-modified Spy0128 pilins readily unfold at very low forces, marking the abrogation of the intramolecular isopeptide bond as well as the absence of a stable pilin fold. We propose that isopeptide-blocking peptides could be further developed as a type of highly specific antiadhesive antibiotics to treat gram-positive pathogens.
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Beitelshees M, Hill A, Jones CH, Pfeifer BA. Phenotypic Variation during Biofilm Formation: Implications for Anti-Biofilm Therapeutic Design. Materials (Basel) 2018; 11:E1086. [PMID: 29949876 DOI: 10.3390/ma11071086] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022]
Abstract
Various bacterial species cycle between growth phases and biofilm formation, of which the latter facilitates persistence in inhospitable environments. These phases can be generally characterized by one or more cellular phenotype(s), each with distinct virulence factor functionality. In addition, a variety of phenotypes can often be observed within the phases themselves, which can be dependent on host conditions or the presence of nutrient and oxygen gradients within the biofilm itself (i.e., microenvironments). Currently, most anti-biofilm strategies have targeted a single phenotype; this approach has driven effective, yet incomplete, protection due to the lack of consideration of gene expression dynamics throughout the bacteria’s pathogenesis. As such, this article provides an overview of the distinct phenotypes found within each biofilm development phase and demonstrates the unique anti-biofilm solutions each phase offers. However, we conclude that a combinatorial approach must be taken to provide complete protection against biofilm forming bacterial and their resulting diseases.
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Abstract
A successful vaccine needs to target multiple strains of an organism. Streptococcus pyogenes is an organism that utilizes antigenic strain variation as a successful defence mechanism to circumvent the host immune response. Despite numerous efforts, there is currently no vaccine available for this organism. Here we review and discuss the significant obstacles to vaccine development, with a focus on how cryptic epitopes may provide a strategy to circumvent the obstacles of antigenic variation.
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Affiliation(s)
- Victoria Ozberk
- a Griffith University, Institute for Glycomics , Gold Coast Campus, Queensland , Australia
| | - Manisha Pandey
- a Griffith University, Institute for Glycomics , Gold Coast Campus, Queensland , Australia
| | - Michael F Good
- a Griffith University, Institute for Glycomics , Gold Coast Campus, Queensland , Australia
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Beitelshees M, Hill A, Rostami P, Jones CH, Pfeifer BA. A Transition to Targeted or ‘Smart’ Vaccines: How Understanding Commensal Colonization Can Lead to Selective Vaccination. Pharmaceut Med 2018. [DOI: 10.1007/s40290-018-0225-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Hurst JR, Kasper KJ, Sule AN, McCormick JK. Streptococcal pharyngitis and rheumatic heart disease: the superantigen hypothesis revisited. Infect Genet Evol 2018; 61:160-75. [PMID: 29530660 DOI: 10.1016/j.meegid.2018.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Streptococcus pyogenes is a human-specific and globally prominent bacterial pathogen that despite causing numerous human infections, this bacterium is normally found in an asymptomatic carrier state. This review provides an overview of both bacterial and human factors that likely play an important role in nasopharyngeal colonization and pharyngitis, as well as the development of acute rheumatic fever and rheumatic heart disease. Here we highlight a recently described role for bacterial superantigens in promoting acute nasopharyngeal infection, and discuss how these immune system activating toxins could be crucial to initiate the autoimmune process in rheumatic heart disease.
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Raynes JM, Young PG, Proft T, Williamson DA, Baker EN, Moreland NJ. Protein adhesins as vaccine antigens for Group A Streptococcus. Pathog Dis 2018; 76:4919728. [DOI: 10.1093/femspd/fty016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/01/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- J M Raynes
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - P G Young
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- School of Biological Sciences, University of Auckland, 5 Symonds Street, Auckland 1010, New Zealand
| | - T Proft
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - D A Williamson
- Microbiological Diagnostic Unit Public Health Laboratory, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - E N Baker
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- School of Biological Sciences, University of Auckland, 5 Symonds Street, Auckland 1010, New Zealand
| | - N J Moreland
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
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Wagachchi D, Tsai JYC, Chalmers C, Blanchett S, Loh JMS, Proft T. PilVax - a novel peptide delivery platform for the development of mucosal vaccines. Sci Rep 2018; 8:2555. [PMID: 29416095 PMCID: PMC5803258 DOI: 10.1038/s41598-018-20863-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/25/2018] [Indexed: 02/02/2023] Open
Abstract
Peptide vaccines are an attractive strategy to engineer the induction of highly targeted immune responses and avoid potentially allergenic and/or reactogenic protein regions. However, peptides by themselves are often unstable and poorly immunogenic, necessitating the need for an adjuvant and a specialised delivery system. We have developed a novel peptide delivery platform (PilVax) that allows the presentation of a stabilised and highly amplified peptide as part of the group A streptococcus serotype M1 pilus structure (PilM1) on the surface of the non-pathogenic bacterium Lactococcus lactis. To show proof of concept, we have successfully inserted the model peptide Ova324–339 into 3 different loop regions of the backbone protein Spy0128, which resulted in the assembly of the pilus containing large numbers of peptide on the surface of L. lactis. Intranasal immunisation of mice with L. lactis PilM1-Ova generated measurable Ova-specific systemic and mucosal responses (IgA and IgG). Furthermore, we show that multiple peptides can be inserted into the PilVax platform and that peptides can also be incorporated into structurally similar, but antigenically different pilus structures. PilVax may be useful as a cost-effective platform for the development of peptide vaccines against a variety of important human pathogens.
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Affiliation(s)
- Dasun Wagachchi
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand
| | - Jia-Yun C Tsai
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand
| | - Callum Chalmers
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand
| | - Sam Blanchett
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand
| | - Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand.
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand.
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Henningham A, Davies MR, Uchiyama S, van Sorge NM, Lund S, Chen KT, Walker MJ, Cole JN, Nizet V. Virulence Role of the GlcNAc Side Chain of the Lancefield Cell Wall Carbohydrate Antigen in Non-M1-Serotype Group A Streptococcus. mBio 2018; 9:e02294-17. [PMID: 29382733 DOI: 10.1128/mBio.02294-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Classification of streptococci is based upon expression of unique cell wall carbohydrate antigens. All serotypes of group A Streptococcus (GAS; Streptococcus pyogenes), a leading cause of infection-related mortality worldwide, express the group A carbohydrate (GAC). GAC, the classical Lancefield antigen, is comprised of a polyrhamnose backbone with N-acetylglucosamine (GlcNAc) side chains. The immunodominant GlcNAc epitope of GAC is the basis of all rapid diagnostic testing for GAS infection. We previously identified the 12-gene GAC biosynthesis gene cluster and determined that the glycosyltransferase GacI was required for addition of the GlcNAc side chain to the polyrhamnose core. Loss of the GAC GlcNAc epitope in serotype M1 GAS resulted in attenuated virulence in two animal infection models and increased GAS sensitivity to killing by whole human blood, serum, neutrophils, and antimicrobial peptides. Here, we report that the GAC biosynthesis gene cluster is ubiquitous among 520 GAS isolates from global sources, representing 105 GAS emm serotypes. Isogenic ΔgacI mutants were constructed in M2, M3, M4, M28, and M89 backgrounds and displayed an array of phenotypes in susceptibility to killing by whole human blood, baby rabbit serum, human platelet releasate, human neutrophils, and antimicrobial peptide LL-37. The contribution of the GlcNAc side chain to GAS survival in vivo also varied by strain, demonstrating that it is not a prerequisite for virulence in the murine infection model. Thus, the relative contribution of GAC to virulence in non-M1 serotypes appears to depend on the quorum of other virulence factors that each strain possesses.IMPORTANCE The Lancefield group A carbohydrate (GAC) is the species-defining antigen for group A Streptococcus (GAS), comprising ~50% of the cell wall of this major human pathogen. We previously showed that the GlcNAc side chain of GAC contributes to the innate immune resistance and animal virulence phenotypes of the globally disseminated strain of serotype M1 GAS. Here, we use isogenic mutagenesis to examine the role of GAC GlcNAc in five additional medically relevant GAS serotypes. Overall, the GlcNAc side chain of GAC contributes to the innate immune resistance of GAS, but the relative contribution varies among individual strains. Moreover, the GAC GlcNAc side chain is not a universal prerequisite for GAS virulence in the animal model.
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Calfee G, Danger JL, Jain I, Miller EW, Sarkar P, Tjaden B, Kreikemeyer B, Sumby P. Identification and Characterization of Serotype-Specific Variation in Group A Streptococcus Pilus Expression. Infect Immun 2018; 86:e00792-17. [PMID: 29158432 DOI: 10.1128/IAI.00792-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 11/13/2017] [Indexed: 12/22/2022] Open
Abstract
Isolates of a given bacterial pathogen often display phenotypic variation, and this can negatively impact public health, for example, by reducing the efficacy of preventative measures. Here, we identify that the human pathogen group A Streptococcus (GAS; Streptococcus pyogenes) expresses pili on its cell surface in a serotype-specific manner. Specifically, we show that serotype M3 GAS isolates, which are nonrandomly associated with causing particularly severe and lethal invasive infections, produce negligible amounts of pili relative to serotype M1 and M49 isolates. Performance of an interserotype transcriptome comparison (serotype M1 versus serotype M3) was instrumental in this discovery. We also identified that the transcriptional regulator Nra positively regulates pilus expression in M3 GAS isolates and that the low level of pilus expression of these isolates correlates with a low level of nra transcription. Finally, we discovered that the phenotypic consequences of low levels of pilus expression by M3 GAS isolates are a reduced ability to adhere to host cells and an increased ability to survive and proliferate in human blood. We propose that an enhanced ability to survive in human blood, in part due to reduced pilus expression, is a contributing factor in the association of serotype M3 isolates with highly invasive infections. In conclusion, our data show that GAS isolates express pili in a serotype-dependent manner and may inform vaccine development, given that pilus proteins are being discussed as possible GAS vaccine antigens.
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Abstract
INTRODUCTION Vaccinology has evolved from a sub-discipline focussed on simplistic vaccine development based on antibody-mediated protection to a separate discipline involving epidemiology, host and pathogen biology, immunology, genomics, proteomics, structure biology, protein engineering, chemical biology, and delivery systems. Data mining in combination with bioinformatics has provided a scaffold linking all these disciplines to the design of vaccines and vaccine adjuvants. Areas covered: This review provides background knowledge on immunological aspects which have been exploited with informatics for the in silico analysis of immune responses and the design of vaccine antigens. Furthermore, the article presents various databases and bioinformatics tools, and discusses B and T cell epitope predictions, antigen design, adjuvant research and systems immunology, highlighting some important examples, and challenges for the future. Expert opinion: Informatics and data mining have not only reduced the time required for experimental immunology, but also contributed to the identification and design of novel vaccine candidates and the determination of biomarkers and pathways of vaccine response. However, more experimental data is required for benchmarking immunoinformatic tools. Nevertheless, developments in immunoinformatics and reverse vaccinology, which are nascent fields, are likely to hasten vaccine discovery, although the path to regulatory approval is likely to remain a necessary impediment.
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Affiliation(s)
| | - S Gauthami
- b Ella Foundation, Turkapally , Hyderabad , India
| | - H M Sampath Kumar
- c Council of Scientific and Industrial Research - Indian Institute of Chemical Technology , Hyderabad , India
| | - Jagadeesh Bayry
- d Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1138 , Centre de Recherche des Cordeliers, Paris , France
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Loh JMS, Lorenz N, Tsai CJ, Khemlani AHJ, Proft T. Mucosal vaccination with pili from Group A Streptococcus expressed on Lactococcus lactis generates protective immune responses. Sci Rep 2017; 7:7174. [PMID: 28775292 DOI: 10.1038/s41598-017-07602-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 06/28/2017] [Indexed: 11/09/2022] Open
Abstract
The human pathogen Group A Streptococcus (GAS) produces pili that are involved in adhesion and colonisation of the host. These surface-exposed pili are immunogenic and therefore represent an attractive target for vaccine development. The pilus is encoded in the genomic region known as the fibronectin-collagen-T-antigen (FCT)-region, of which at least nine different types have been identified. In this study we investigate expressing two of the most common FCT-types (FCT-3 and FCT-4) in the food-grade bacteria Lactococcus lactis for use as a mucosal vaccine. We show that mucosally delivered L. lactis expressing GAS pili generates specific antibody responses in rabbits. Rabbit anti-pilus antibodies were shown to have both a neutralising effect on bacterial adhesion, and immunised rabbit antiserum was able to facilitate immune-mediated killing of bacteria via opsonophagocytosis. Furthermore, intranasal immunisation of mice improved clearance rates of GAS after nasopharyngeal challenge. These results demonstrate the potential for a novel, pilus-based vaccine to protect against GAS infections.
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49
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Khare B, V L Narayana S. Pilus biogenesis of Gram-positive bacteria: Roles of sortases and implications for assembly. Protein Sci 2017; 26:1458-1473. [PMID: 28493331 DOI: 10.1002/pro.3191] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/28/2017] [Accepted: 05/03/2017] [Indexed: 12/26/2022]
Abstract
Successful adherence, colonization, and survival of Gram-positive bacteria require surface proteins, and multiprotein assemblies called pili. These surface appendages are attractive pharmacotherapeutic targets and understanding their assembly mechanisms is essential for identifying a new class of 'anti-infectives' that do not elicit microbial resistance. Molecular details of the Gram-negative pilus assembly are available indepth, but the Gram-positive pilus biogenesis is still an emerging field and investigations continue to reveal novel insights into this process. Pilus biogenesis in Gram-positive bacteria is a biphasic process that requires enzymes called pilus-sortases for assembly and a housekeeping sortase for covalent attachment of the assembled pilus to the peptidoglycan cell wall. Emerging structural and functional data indicate that there are at least two groups of Gram-positive pili, which require either the Class C sortase or Class B sortase in conjunction with LepA/SipA protein for major pilin polymerization. This observation suggests two distinct modes of sortase-mediated pilus biogenesis in Gram-positive bacteria. Here we review the structural and functional biology of the pilus-sortases from select streptococcal pilus systems and their role in Gram-positive pilus assembly.
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Affiliation(s)
- Baldeep Khare
- Center for Structural Biology, School of Optometry, University of Alabama at Birmingham, Birmingham, USA
| | - Sthanam V L Narayana
- Center for Structural Biology, School of Optometry, University of Alabama at Birmingham, Birmingham, USA
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Wang Y, Li J, Zhang A, Zhu W, Zhang Q, Xu Z, Yan S, Sun X, Chen H, Jin M. iTRAQ-based quantitative proteomic analysis reveals potential virulence factors of Erysipelothrix rhusiopathiae. J Proteomics 2017; 160:28-37. [DOI: 10.1016/j.jprot.2017.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 03/01/2017] [Accepted: 03/04/2017] [Indexed: 12/28/2022]
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