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Werren JP, Mostacci N, Gjuroski I, Holivololona L, Troxler LJ, Hathaway LJ, Furrer J, Hilty M. Carbon source-dependent capsule thickness regulation in Streptococcus pneumoniae. Front Cell Infect Microbiol 2023; 13:1279119. [PMID: 38094742 PMCID: PMC10716237 DOI: 10.3389/fcimb.2023.1279119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023] Open
Abstract
Background The polysaccharide capsule of Streptococcus pneumoniae plays a major role in virulence, adherence to epithelial cells, and overall survival of the bacterium in the human host. Galactose, mannose, and N-acetylglucosamine (GlcNAc) are likely to be relevant for metabolization in the nasopharynx, while glucose is the primary carbon source in the blood. In this study, we aim to further the understanding of the influence of carbon sources on pneumococcal growth, capsule biosynthesis, and subsequent adherence potential. Methods We tested the growth behavior of clinical wild-type and capsule knockout S. pneumoniae strains, using galactose, GlcNAc, mannose, and glucose as carbon source for growth. We measured capsule thickness and quantified capsule precursors by fluorescein isothiocyanate (FITC)-dextran exclusion assays and 31P-nuclear magnetic resonance measurements, respectively. We also performed epithelial adherence assays using Detroit 562 cells and performed a transcriptome analysis (RNA sequencing). Results We observed a reduced growth in galactose, mannose, and GlcNAc compared to growth in glucose and found capsular size reductions in mannose and GlcNAc compared to galactose and glucose. Additionally, capsular precursor measurements of uridine diphosphate-(UDP)-glucose and UDP-galactose showed less accumulation of precursors in GlcNAc or mannose than in glucose and galactose, indicating a possible link with the received capsular thickness measurements. Epithelial adherence assays showed an increase in adherence potential for a pneumococcal strain, when grown in mannose compared to glucose. Finally, transcriptome analysis of four clinical isolates revealed not only strain specific but also common carbon source-specific gene expression. Conclusion Our findings may indicate a careful adaption of the lifestyle of S. pneumoniae according to the monosaccharides encountered in the respective human niche.
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Affiliation(s)
- Joel P. Werren
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Nadja Mostacci
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Ilche Gjuroski
- Department of Chemistry, Biochemistry and Pharmacy, University of Bern, Bern, Switzerland
| | - Lalaina Holivololona
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Lukas J. Troxler
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Lucy J. Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Julien Furrer
- Department of Chemistry, Biochemistry and Pharmacy, University of Bern, Bern, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
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2
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Zhu J, Abruzzo AR, Wu C, Bee GCW, Pironti A, Putzel G, Aggarwal SD, Eichner H, Weiser JN. Effects of Capsular Polysaccharide amount on Pneumococcal-Host interactions. PLoS Pathog 2023; 19:e1011509. [PMID: 37540710 PMCID: PMC10431664 DOI: 10.1371/journal.ppat.1011509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/16/2023] [Accepted: 06/24/2023] [Indexed: 08/06/2023] Open
Abstract
Among the many oral streptococci, Streptococcus pneumoniae (Spn) stands out for the capacity of encapsulated strains to cause invasive infection. Spread beyond upper airways, however, is a biological dead end for the organism, raising the question of the benefits of expending energy to coat its surface in a thick layer of capsular polysaccharide (CPS). In this study, we compare mutants of two serotypes expressing different amounts of CPS and test these in murine models of colonization, invasion infection and transmission. Our analysis of the effect of CPS amount shows that Spn expresses a capsule of sufficient thickness to shield its surface from the deposition of complement and binding of antibody to underlying epitopes. While effective shielding is permissive for invasive infection, its primary contribution to the organism appears to be in the dynamics of colonization. A thicker capsule increases bacterial retention in the nasopharynx, the first event in colonization, and also impedes IL-17-dependent clearance during late colonization. Enhanced colonization is associated with increased opportunity for host-to-host transmission. Additionally, we document substantial differences in CPS amount among clinical isolates of three common serotypes. Together, our findings show that CPS amount is highly variable among Spn and could be an independent determinant affecting host interactions.
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Affiliation(s)
- Jiaqi Zhu
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Annie R. Abruzzo
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Cindy Wu
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Gavyn Chern Wei Bee
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
- Microbial Computational Genomic Core Lab, Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Gregory Putzel
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
- Microbial Computational Genomic Core Lab, Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Surya D. Aggarwal
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Hannes Eichner
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, and Clinical Microbiology, Bioclinicum, Karolinska University Hospital Solna, Solna, Sweden
| | - Jeffrey N. Weiser
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
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3
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Zhang Y, Zhang J, Xiao J, Wang H, Yang R, Guo X, Zheng Y, Yin Y, Zhang X. comCDE (Competence) Operon Is Regulated by CcpA in Streptococcus pneumoniae D39. Microbiol Spectr 2023; 11:e0001223. [PMID: 37036382 PMCID: PMC10269683 DOI: 10.1128/spectrum.00012-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/16/2023] [Indexed: 04/11/2023] Open
Abstract
Natural transformation plays an important role in the formation of drug-resistant bacteria. Exploring the regulatory mechanism of natural transformation can aid the discovery of new antibacterial targets and reduce the emergence of drug-resistant bacteria. Competence is a prerequisite of natural transformation in Streptococcus pneumoniae, in which comCDE operon is the core regulator of competence. To date, only ComE has been shown to directly regulate comCDE transcription. In this study, a transcriptional regulator, the catabolite control protein A (CcpA), was identified that directly regulated comCDE transcription. We confirmed that CcpA binds to the cis-acting catabolite response elements (cre) in the comCDE promoter region to regulate comCDE transcription and transformation. Moreover, CcpA can coregulate comCDE transcription with phosphorylated and dephosphorylated ComE. Regulation of comCDE transcription and transformation by CcpA was also affected by carbon source signals. Together, these insights demonstrate the versatility of CcpA and provide a theoretical basis for reducing the emergence of drug-resistant bacteria. IMPORTANCE Streptococcus pneumoniae is a major cause of bacterial infections in humans, such as pneumonia, bacteremia, meningitis, otitis media, and sinusitis. Like most streptococci, S. pneumoniae is naturally competent and employs this ability to augment its adaptive evolution. The current study illustrates CcpA, a carbon catabolite regulator, can participate in the competence process by regulating comCDE transcription, and this process is regulated by different carbon source signals. These hidden abilities are likely critical for adaptation and colonization in the environment.
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Affiliation(s)
- Yapeng Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | | | - Jiangming Xiao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hanyi Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Rui Yang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xinlin Guo
- Department of Medicine Laboratory, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Yuqiang Zheng
- Department of Medicine Laboratory, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Yibing Yin
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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4
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Echlin H, Iverson A, Sardo U, Rosch JW. Airway proteolytic control of pneumococcal competence. PLoS Pathog 2023; 19:e1011421. [PMID: 37256908 PMCID: PMC10259803 DOI: 10.1371/journal.ppat.1011421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 06/12/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that colonizes the upper respiratory tract asymptomatically and, upon invasion, can lead to severe diseases including otitis media, sinusitis, meningitis, bacteremia, and pneumonia. One of the first lines of defense against pneumococcal invasive disease is inflammation, including the recruitment of neutrophils to the site of infection. The invasive pneumococcus can be cleared through the action of serine proteases generated by neutrophils. It is less clear how serine proteases impact non-invasive pneumococcal colonization, which is the key first step to invasion and transmission. One significant aspect of pneumococcal biology and adaptation in the respiratory tract is its natural competence, which is triggered by a small peptide CSP. In this study, we investigate if serine proteases are capable of degrading CSP and the impact this has on pneumococcal competence. We found that CSP has several potential sites for trypsin-like serine protease degradation and that there were preferential cleavage sites recognized by the proteases. Digestion of CSP with two different trypsin-like serine proteases dramatically reduced competence in a dose-dependent manner. Incubation of CSP with mouse lung homogenate also reduced recombination frequency of the pneumococcus. These ex vivo experiments suggested that serine proteases in the lower respiratory tract reduce pneumococcal competence. This was subsequently confirmed measuring in vivo recombination frequencies after induction of protease production via poly (I:C) stimulation and via co-infection with influenza A virus, which dramatically lowered recombination events. These data shed light on a new mechanism by which the host can modulate pneumococcal behavior and genetic exchange via direct degradation of the competence signaling peptide.
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Affiliation(s)
- Haley Echlin
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Amy Iverson
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Ugo Sardo
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
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5
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AmiA and AliA peptide ligands are secreted by Klebsiella pneumoniae and inhibit growth of Streptococcus pneumoniae. Sci Rep 2022; 12:22268. [PMID: 36564446 PMCID: PMC9789142 DOI: 10.1038/s41598-022-26838-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
Streptococcus pneumoniae colonizes the human nasopharynx, a multi-species microbial niche. Pneumococcal Ami-AliA/AliB oligopeptide permease is an ABC transporter involved in environmental sensing with peptides AKTIKITQTR, FNEMQPIVDRQ, and AIQSEKARKHN identified as ligands of its substrate binding proteins AmiA, AliA, and AliB, respectively. These sequences match ribosomal proteins of multiple bacterial species, including Klebsiella pneumoniae. By mass spectrometry, we identified such peptides in the Klebsiella pneumoniae secretome. AmiA and AliA peptide ligands suppressed pneumococcal growth, but the effect was dependent on peptide length. Growth was suppressed for diverse pneumococci, including antibiotic-resistant strains, but not other bacterial species tested, with the exception of Streptococcus pseudopneumoniae, whose growth was suppressed by the AmiA peptide ligand. By multiple sequence alignments and protein and peptide binding site predictions, for AmiA we have identified the location of an amino acid in the putative binding site whose mutation appears to result in loss of response to the peptide. Our results indicate that pneumococci sense the presence of Klebsiella pneumoniae peptides in the environment.
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6
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Tonkin-Hill G, Ling C, Chaguza C, Salter SJ, Hinfonthong P, Nikolaou E, Tate N, Pastusiak A, Turner C, Chewapreecha C, Frost SDW, Corander J, Croucher NJ, Turner P, Bentley SD. Pneumococcal within-host diversity during colonization, transmission and treatment. Nat Microbiol 2022; 7:1791-1804. [PMID: 36216891 PMCID: PMC9613479 DOI: 10.1038/s41564-022-01238-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022]
Abstract
Characterizing the genetic diversity of pathogens within the host promises to greatly improve surveillance and reconstruction of transmission chains. For bacteria, it also informs our understanding of inter-strain competition and how this shapes the distribution of resistant and sensitive bacteria. Here we study the genetic diversity of Streptococcus pneumoniae within 468 infants and 145 of their mothers by deep sequencing whole pneumococcal populations from 3,761 longitudinal nasopharyngeal samples. We demonstrate that deep sequencing has unsurpassed sensitivity for detecting multiple colonization, doubling the rate at which highly invasive serotype 1 bacteria were detected in carriage compared with gold-standard methods. The greater resolution identified an elevated rate of transmission from mothers to their children in the first year of the child's life. Comprehensive treatment data demonstrated that infants were at an elevated risk of both the acquisition and persistent colonization of a multidrug-resistant bacterium following antimicrobial treatment. Some alleles were enriched after antimicrobial treatment, suggesting that they aided persistence, but generally purifying selection dominated within-host evolution. Rates of co-colonization imply that in the absence of treatment, susceptible lineages outcompeted resistant lineages within the host. These results demonstrate the many benefits of deep sequencing for the genomic surveillance of bacterial pathogens.
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Affiliation(s)
- Gerry Tonkin-Hill
- grid.10306.340000 0004 0606 5382Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK ,grid.5510.10000 0004 1936 8921Department of Biostatistics, University of Oslo, Blindern, Norway
| | - Clare Ling
- grid.10223.320000 0004 1937 0490Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chrispin Chaguza
- grid.10306.340000 0004 0606 5382Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK ,grid.47100.320000000419368710Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT USA
| | - Susannah J. Salter
- grid.5335.00000000121885934Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Pattaraporn Hinfonthong
- grid.10223.320000 0004 1937 0490Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Elissavet Nikolaou
- grid.48004.380000 0004 1936 9764Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK ,grid.1058.c0000 0000 9442 535XInfection and Immunity, Murdoch Children’s Research Institute, Melbourne, Victoria Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria Australia
| | - Natalie Tate
- grid.48004.380000 0004 1936 9764Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Claudia Turner
- grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK ,grid.459332.a0000 0004 0418 5364Cambodia-Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
| | - Claire Chewapreecha
- grid.10306.340000 0004 0606 5382Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK ,grid.10223.320000 0004 1937 0490Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Simon D. W. Frost
- grid.419815.00000 0001 2181 3404Microsoft Research, Redmond, WA USA ,grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, London, UK
| | - Jukka Corander
- grid.10306.340000 0004 0606 5382Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK ,grid.5510.10000 0004 1936 8921Department of Biostatistics, University of Oslo, Blindern, Norway ,grid.7737.40000 0004 0410 2071Helsinki Institute for Information Technology HIIT, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - Nicholas J. Croucher
- grid.7445.20000 0001 2113 8111MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Paul Turner
- grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK ,grid.459332.a0000 0004 0418 5364Cambodia-Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
| | - Stephen D. Bentley
- grid.10306.340000 0004 0606 5382Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
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7
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Noble K, Lu J, Guevara MA, Doster RS, Chambers SA, Rogers LM, Moore RE, Spicer SK, Eastman AJ, Francis JD, Manning SD, Rajagopal L, Aronoff DM, Townsend SD, Gaddy JA. Group B Streptococcus cpsE Is Required for Serotype V Capsule Production and Aids in Biofilm Formation and Ascending Infection of the Reproductive Tract during Pregnancy. ACS Infect Dis 2021; 7:2686-2696. [PMID: 34076405 DOI: 10.1021/acsinfecdis.1c00182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Group B Streptococcus (GBS) is an encapsulated Gram-positive pathogen that causes ascending infections of the reproductive tract during pregnancy. The capsule of this organism is a critical virulence factor that has been implicated in a variety of cellular processes to promote pathogenesis. Primarily comprised of carbohydrates, the GBS capsule and its synthesis is driven by the capsule polysaccharide synthesis (cps) operon. The cpsE gene within this operon encodes a putative glycosyltransferase that is responsible for the transfer of a Glc-1-P from UDP-Glc to an undecaprenyl lipid molecule. We hypothesized that the cpsE gene product is important for GBS virulence and ascending infection during pregnancy. Our work demonstrates that a GBS cpsE mutant secretes fewer carbohydrates, has a reduced capsule, and forms less biofilm than the wild-type parental strain. We show that, compared to the parental strain, the ΔcpsE deletion mutant is more readily taken up by human placental macrophages and has a significantly attenuated ability to invade and proliferate in the mouse reproductive tract. Taken together, these results demonstrate that the cpsE gene product is an important virulence factor that aids in GBS colonization and invasion of the gravid reproductive tract.
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Affiliation(s)
- Kristen Noble
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Miriam A. Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Schuyler A. Chambers
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Lisa M. Rogers
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Rebecca E. Moore
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Sabrina K. Spicer
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Alison J. Eastman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
| | - Jamisha D. Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48823, United States
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington, Seattle, Washington 98109, United States
| | - David M. Aronoff
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Departments of Biochemistry and Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Steven D. Townsend
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jennifer A. Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37212, United States
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, United States
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee 37212, United States
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8
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Inactivation of Transcriptional Regulator FabT Influences Colony Phase Variation of Streptococcus pneumoniae. mBio 2021; 12:e0130421. [PMID: 34399624 PMCID: PMC8406281 DOI: 10.1128/mbio.01304-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that can alter its cell surface phenotype in response to the host environment. We demonstrated that the transcriptional regulator FabT is an indirect regulator of capsular polysaccharide, an important virulence factor of Streptococcus pneumoniae. Transcriptome analysis between the wild-type D39s and D39ΔfabT mutant strains unexpectedly identified a differentially expressed gene encoding a site-specific recombinase, PsrA. PsrA catalyzes the inversion of 3 homologous hsdS genes in a type I restriction-modification (RM) system SpnD39III locus and is responsible for the reversible switch of phase variation. Our study demonstrated that upregulation of PsrA in a D39ΔfabT mutant correlated with an increased ratio of transparent (T) phase variants. Inactivation of the invertase PsrA led to uniform opaque (O) variants. Direct quantification of allelic variants of hsdS derivatives and inversions of inverted repeats indicated that the recombinase PsrA fully catalyzes the inversion mediated by IR1 and IR3, and FabT mediated the recombination of the hsdS alleles in PsrA-dependent and PsrA-independent manners. In addition, compared to D39s, the ΔfabT mutant exhibited reduced nasopharyngeal colonization and was more resistant to phagocytosis and less adhesive to epithelial cells. These results indicated that phase variation in the ΔfabT mutant also affects other cell surface components involved in host interactions.
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Generation and Evaluation of a Glaesserella (Haemophilus) parasuis Capsular Mutant. Infect Immun 2020; 88:IAI.00879-19. [PMID: 32094250 DOI: 10.1128/iai.00879-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/14/2020] [Indexed: 01/18/2023] Open
Abstract
Glaesserella (Haemophilus) parasuis is a commensal bacterium of the upper respiratory tract in pigs and also the causative agent of Glässer's disease, which causes significant morbidity and mortality in pigs worldwide. Isolates are characterized into 15 serovars by their capsular polysaccharide, which has shown a correlation with isolate pathogenicity. To investigate the role the capsule plays in G. parasuis virulence and host interaction, a capsule mutant of the serovar 5 strain HS069 was generated (HS069Δcap) through allelic exchange following natural transformation. HS069Δcap was unable to cause signs of systemic disease during a pig challenge study and had increased sensitivity to complement killing and phagocytosis by alveolar macrophages. Compared with the parent strain, HS069Δcap produced more robust biofilm and adhered equivalently to 3D4/31 cells; however, it was unable to persistently colonize the nasal cavity of inoculated pigs, with all pigs clearing HS069Δcap by 5 days postchallenge. Our results indicate the importance of the capsular polysaccharide to G. parasuis virulence as well as nasal colonization in pigs.
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Disruption of the cpsE and endA Genes Attenuates Streptococcus pneumoniae Virulence: Towards the Development of a Live Attenuated Vaccine Candidate. Vaccines (Basel) 2020; 8:vaccines8020187. [PMID: 32326482 PMCID: PMC7349068 DOI: 10.3390/vaccines8020187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/27/2020] [Accepted: 04/07/2020] [Indexed: 12/15/2022] Open
Abstract
The majority of deaths due to Streptococcus pneumoniae infections are in developing countries. Although polysaccharide-based pneumococcal vaccines are available, newer types of vaccines are needed to increase vaccine affordability, particularly in developing countries, and to provide broader protection across all pneumococcal serotypes. To attenuate pneumococcal virulence with the aim of engineering candidate live attenuated vaccines (LAVs), we constructed knockouts in S. pneumoniae D39 of one of the capsular biosynthetic genes, cpsE that encodes glycosyltransferase, and the endonuclease gene, endA, that had been implicated in the uptake of DNA from the environment as well as bacterial escape from neutrophil-mediated killing. The cpsE gene knockout significantly lowered peak bacterial density, BALB/c mice nasopharyngeal (NP) colonisation but increased biofilm formation when compared to the wild-type D39 strain as well as the endA gene knockout mutant. All constructed mutant strains were able to induce significantly high serum and mucosal antibody response in BALB/c mice. However, the cpsE-endA double mutant strain, designated SPEC, was able to protect mice from high dose mucosal challenge of the D39 wild-type. Furthermore, SPEC showed 23-fold attenuation of virulence compared to the wild-type. Thus, the cpsE-endA double-mutant strain could be a promising candidate for further development of a LAV for S. pneumoniae.
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11
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Deletion of the Zinc Transporter Lipoprotein AdcAII Causes Hyperencapsulation of Streptococcus pneumoniae Associated with Distinct Alleles of the Type I Restriction-Modification System. mBio 2020; 11:mBio.00445-20. [PMID: 32234814 PMCID: PMC7157770 DOI: 10.1128/mbio.00445-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The Streptococcus pneumoniae capsule affects multiple interactions with the host including contributing to colonization and immune evasion. During infection, the capsule thickness varies, but the mechanisms regulating this are poorly understood. We have identified an unsuspected relationship between mutation of adcAII, a gene that encodes a zinc uptake lipoprotein, and capsule thickness. Mutation of adcAII resulted in a striking hyperencapsulated phenotype, increased resistance to complement-mediated neutrophil killing, and increased S. pneumoniae virulence in mouse models of infection. Transcriptome and PCR analysis linked the hyperencapsulated phenotype of the ΔadcAII strain to specific alleles of the SpnD39III (ST5556II) type I restriction-modification system, a system which has previously been shown to affect capsule thickness. Our data provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identify an unexpected link between capsule thickness and ΔadcAII, further investigation of which could further characterize mechanisms of capsule regulation. The capsule is the dominant Streptococcus pneumoniae virulence factor, yet how variation in capsule thickness is regulated is poorly understood. Here, we describe an unexpected relationship between mutation of adcAII, which encodes a zinc uptake lipoprotein, and capsule thickness. Partial deletion of adcAII in three of five capsular serotypes frequently resulted in a mucoid phenotype that biochemical analysis and electron microscopy of the D39 adcAII mutants confirmed was caused by markedly increased capsule thickness. Compared to D39, the hyperencapsulated ΔadcAII mutant strain was more resistant to complement-mediated neutrophil killing and was hypervirulent in mouse models of invasive infection. Transcriptome analysis of D39 and the ΔadcAII mutant identified major differences in transcription of the Sp_0505-0508 locus, which encodes an SpnD39III (ST5556II) type I restriction-modification system and allelic variation of which correlates with capsule thickness. A PCR assay demonstrated close linkage of the SpnD39IIIC and F alleles with the hyperencapsulated ΔadcAII strains. However, transformation of ΔadcAII with fixed SpnD39III alleles associated with normal capsule thickness did not revert the hyperencapsulated phenotype. Half of hyperencapsulated ΔadcAII strains contained the same single nucleotide polymorphism in the capsule locus gene cps2E, which is required for the initiation of capsule synthesis. These results provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identified an unexpected linkage between capsule thickness and mutation of ΔadcAII. Further investigation will be needed to characterize how mutation of adcAII affects SpnD39III (ST5556II) allele dominance and results in the hyperencapsulated phenotype.
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Müller A, Salmen A, Aebi S, de Gouveia L, von Gottberg A, Hathaway LJ. Pneumococcal serotype determines growth and capsule size in human cerebrospinal fluid. BMC Microbiol 2020; 20:16. [PMID: 31959125 PMCID: PMC6971925 DOI: 10.1186/s12866-020-1700-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 01/09/2020] [Indexed: 12/02/2022] Open
Abstract
Background The polysaccharide capsule is a major virulence factor of S. pneumoniae in diseases such as meningitis. While some capsular serotypes are more often found in invasive disease, high case fatality rates are associated with those serotypes more commonly found in asymptomatic colonization. We tested whether growth patterns and capsule size in human cerebrospinal fluid depends on serotype using a clinical isolate of S. pneumoniae and its capsule switch mutants. Results We found that the growth pattern differed markedly from that in culture medium by lacking the exponential and lysis phases. Growth in human cerebrospinal fluid was reduced when strains lost their capsules. When a capsule was present, growth was serotype-specific: high carriage serotypes (6B, 9 V, 19F and 23F) grew better than low carriage serotypes (7F, 14, 15B/C and 18C). Growth correlated with the case-fatality rates of serotypes reported in the literature. Capsule size in human cerebrospinal fluid also depended on serotype. Conclusions We propose that serotype-specific differences in disease severity observed in meningitis patients may, at least in part, be explained by differences in growth and capsule size in human cerebrospinal fluid. This information could be useful to guide future vaccine design.
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Affiliation(s)
- Annelies Müller
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Anke Salmen
- Department of Neurology, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland
| | - Suzanne Aebi
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland
| | - Linda de Gouveia
- National Institute for Communicable Diseases: Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Anne von Gottberg
- National Institute for Communicable Diseases: Division of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, School of Pathology, University of Witwatersrand, Johannesburg, South Africa
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland.
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13
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Mohale T, Wolter N, Allam M, Nzenze SA, Madhi SA, du Plessis M, von Gottberg A. Genomic differences among carriage and invasive nontypeable pneumococci circulating in South Africa. Microb Genom 2019; 5. [PMID: 31617841 PMCID: PMC6861859 DOI: 10.1099/mgen.0.000299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Most pneumococci express a polysaccharide capsule, a key virulence factor and target for pneumococcal vaccines. However, pneumococci showing no serological evidence of capsule expression [nontypeable pneumococci (NTPn)] are more frequently isolated from carriage studies than in invasive disease. Limited data exist about the population structure of carriage NTPn from the African continent. We aimed to characterize carriage NTPn and compare them to previously described invasive NTPn. Carriage and invasive NTPn isolates were obtained from South African cross-sectional studies (2009 and 2012) and laboratory-based surveillance for invasive pneumococcal disease (2003–2013), respectively. Isolates were characterized by capsular locus sequence analysis, multilocus sequence typing, antimicrobial non-susceptibility patterns and phylogenetic analysis. NTPn represented 3.7 % (137/3721) of carriage isolates compared to 0.1 % (39/32 824) of invasive isolates (P<0.001), and 24 % (33/137) of individuals were co-colonized with encapsulated pneumococci. Non-susceptibility to cotrimoxazole [84 % (112/133) vs 44 % (17/39)], penicillin [77 % (102/133) vs 36 % (14/39)], erythromycin [53 % (70/133) vs 31 % (12/39)] and clindamycin [36 % (48/133) vs 18 % (7/39)] was higher (P=0.03) among carriage than invasive NTPn. Ninety-one per cent (124/137) of carriage NTPn had complete deletion of the capsular locus and 9 % (13/137) had capsule genes, compared to 44 % (17/39) and 56 % (22/39) of invasive NTPn, respectively. Carriage NTPn were slightly less diverse [Simpson’s diversity index (D)=0.92] compared to invasive NTPn [D=0.97]. Sixty-seven per cent (92/137) of carriage NTPn belonged to a lineage exclusive to NTPn strains compared to 23 % (9/39) of invasive NTPn. We identified 293 and 275 genes that were significantly associated with carriage and invasive NTPn, respectively. NTPn isolates detected in carriage differed from those causing invasive disease, which may explain their success in colonisation or in causing invasive disease.
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Affiliation(s)
- Thabo Mohale
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa.,Clinical Microbiology and Infectious Diseases, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nicole Wolter
- Clinical Microbiology and Infectious Diseases, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Mushal Allam
- Sequencing Core Facility, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Susan A Nzenze
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases Research Chair, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases Research Chair, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mignon du Plessis
- Clinical Microbiology and Infectious Diseases, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Anne von Gottberg
- Clinical Microbiology and Infectious Diseases, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
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14
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Troxler LJ, Werren JP, Schaffner TO, Mostacci N, Vermathen P, Vermathen M, Wüthrich D, Simillion C, Brugger SD, Bruggmann R, Hathaway LJ, Furrer J, Hilty M. Carbon source regulates polysaccharide capsule biosynthesis in Streptococcus pneumoniae. J Biol Chem 2019; 294:17224-17238. [PMID: 31594867 PMCID: PMC6873171 DOI: 10.1074/jbc.ra119.010764] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/02/2019] [Indexed: 11/06/2022] Open
Abstract
The exopolysaccharide capsule of Streptococcus pneumoniae is an important virulence factor, but the mechanisms that regulate capsule thickness are not fully understood. Here, we investigated the effects of various exogenously supplied carbohydrates on capsule production and gene expression in several pneumococcal serotypes. Microscopy analyses indicated a near absence of the capsular polysaccharide (CPS) when S. pneumoniae was grown on fructose. Moreover, serotype 7F pneumococci produced much less CPS than strains of other serotypes (6B, 6C, 9V, 15, and 23F) when grown on glucose or sucrose. RNA-sequencing revealed carbon source-dependent regulation of distinct genes of WT strains and capsule-switch mutants of serotypes 6B and 7F, but could not explain the mechanism of capsule thickness regulation. In contrast, 31P NMR of whole-cell extract from capsule-knockout strains (Δcps) clearly revealed the accumulation or absence of capsule precursor metabolites when cells were grown on glucose or fructose, respectively. This finding suggests that fructose uptake mainly results in intracellular fructose 1-phosphate, which is not converted to CPS precursors. In addition, serotype 7F strains accumulated more precursors than did 6B strains, indicating less efficient conversion of precursor metabolites into the CPS in 7F, in line with its thinner capsule. Finally, isotopologue sucrose labeling and NMR analyses revealed that the uptake of the labeled fructose subunit into the capsule is <10% that of glucose. Our findings on the effects of carbon sources on CPS production in different S. pneumoniae serotypes may contribute to a better understanding of pneumococcal diseases and could inform future therapeutic approaches.
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Affiliation(s)
- Lukas J Troxler
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Joel P Werren
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Thierry O Schaffner
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Nadezda Mostacci
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Peter Vermathen
- Department of BioMedical Research and Radiology, University of Bern and Inselspital, 3012 Bern, Switzerland
| | - Martina Vermathen
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Daniel Wüthrich
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland.,Applied Microbiology Research Unit, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland.,Division of Clinical Microbiology, University Hospital Basel, 4031 Basel, Switzerland
| | - Cedric Simillion
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland
| | - Silvio D Brugger
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland.,The Forsyth Institute (Microbiology), Cambridge, Massachusetts 02142.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts 02142
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Julien Furrer
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
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15
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Nasher F, Kwun MJ, Croucher NJ, Heller M, Hathaway LJ. Peptide Occurring in Enterobacteriaceae Triggers Streptococcus pneumoniae Cell Death. Front Cell Infect Microbiol 2019; 9:320. [PMID: 31552200 PMCID: PMC6748166 DOI: 10.3389/fcimb.2019.00320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/26/2019] [Indexed: 11/15/2022] Open
Abstract
Non-encapsulated Streptococcus pneumoniae often possess two genes, aliB-like ORF 1 and aliB-like ORF 2, in place of capsule genes. AliB-like ORF 1 is thought to encode a substrate binding protein of an ABC transporter which binds peptide SETTFGRDFN, found in 50S ribosomal subunit protein L4 of Enterobacteriaceae. Here, we investigated the effect of binding of AliB-like ORF 1 peptide on the transcriptome and proteome of non-encapsulated pneumococci. We found upregulation of gene expression of a metacaspase and a gene encoding N-acetylmuramoyl-L-alanine amidase, both of which are proposed to be involved in programmed cell death in prokaryotic cells. Proteome profiling indicated upregulation of transcriptional regulators and downregulation of metabolism-associated genes. Exposure to the peptide specifically triggered death in pneumococci which express AliB-like ORF 1, with the bacteria having an apoptotic appearance by electron microscopy. We propose that binding of the AliB-like ORF 1 peptide ligand by the pneumococcus signals a challenging environment with hostile bacterial species leading to death of a proportion of the pneumococcal population.
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Affiliation(s)
- Fauzy Nasher
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Min Jung Kwun
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Nicholas J Croucher
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
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16
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Rendueles O, de Sousa JAM, Bernheim A, Touchon M, Rocha EPC. Genetic exchanges are more frequent in bacteria encoding capsules. PLoS Genet 2018; 14:e1007862. [PMID: 30576310 PMCID: PMC6322790 DOI: 10.1371/journal.pgen.1007862] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/07/2019] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Capsules allow bacteria to colonize novel environments, to withstand numerous stresses, and to resist antibiotics. Yet, even though genetic exchanges with other cells should be adaptive under such circumstances, it has been suggested that capsules lower the rates of homologous recombination and horizontal gene transfer. We analysed over one hundred pan-genomes and thousands of bacterial genomes for the evidence of an association between genetic exchanges (or lack thereof) and the presence of a capsule system. We found that bacteria encoding capsules have larger pan-genomes, higher rates of horizontal gene transfer, and higher rates of homologous recombination in their core genomes. Accordingly, genomes encoding capsules have more plasmids, conjugative elements, transposases, prophages, and integrons. Furthermore, capsular loci are frequent in plasmids, and can be found in prophages. These results are valid for Bacteria, independently of their ability to be naturally transformable. Since we have shown previously that capsules are commonly present in nosocomial pathogens, we analysed their co-occurrence with antibiotic resistance genes. Genomes encoding capsules have more antibiotic resistance genes, especially those encoding efflux pumps, and they constitute the majority of the most worrisome nosocomial bacteria. We conclude that bacteria with capsule systems are more genetically diverse and have fast-evolving gene repertoires, which may further contribute to their success in colonizing novel niches such as humans under antibiotic therapy. Previous works showed that bacteria encoding capsules are better colonizers and are dominant in most environments suggesting a positive role for capsules in the genetic diversification of bacteria. Yet, it has been repeatedly suggested, based almost exclusively studies in few model species, that such bacteria are less diverse and engage in fewer genetic exchanges. Here, we reverse the current paradigm and show that bacteria encoding capsules have larger and more diverse gene repertoires, which change faster by horizontal gene transfer and recombination. Our study alters the traditional view of the capsule as a barrier to gene flow and raises novel questions about the role of capsules in bacterial adaptation.
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Affiliation(s)
- Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
- * E-mail:
| | - Jorge A. Moura de Sousa
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Aude Bernheim
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
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17
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Nasher F, Aguilar F, Aebi S, Hermans PWM, Heller M, Hathaway LJ. Peptide Ligands of AmiA, AliA, and AliB Proteins Determine Pneumococcal Phenotype. Front Microbiol 2018; 9:3013. [PMID: 30568648 PMCID: PMC6290326 DOI: 10.3389/fmicb.2018.03013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/21/2018] [Indexed: 12/13/2022] Open
Abstract
The Ami-AliA/AliB oligopeptide permease of Streptococcus pneumoniae has been suggested to play a role in environmental sensing and colonisation of the nasopharynx by this human bacterial pathogen by binding peptides derived from bacterial neighbours of other species in the microbiota. Here, we investigated the effects of the peptide ligands of the permease’s substrate binding proteins AmiA, AliA, and AliB on pneumococcal phenotype. AmiA and AliA ligands reduced pneumococcal growth, increased biofilm production and reduced capsule size. In contrast, AliB ligand increased growth and greatly increased bacterial chain length. A decrease in transformation rate was observed in response to all three peptides. Changes in protein expression were also observed, particularly those associated with metabolism and cell wall synthesis. Understanding interspecies bacterial communication and its effect on development of colonising versus invasive phenotypes has the potential to reveal new targets to tackle and prevent pneumococcal infections.
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Affiliation(s)
- Fauzy Nasher
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Fernando Aguilar
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Suzanne Aebi
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Peter W M Hermans
- Janssen Vaccines and Prevention, Leiden, Netherlands.,Julius Center, UMC Utrecht, Utrecht, Netherlands
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland
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18
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Tikhomirova A, Trappetti C, Standish AJ, Zhou Y, Breen J, Pederson S, Zilm PS, Paton JC, Kidd SP. Specific growth conditions induce a Streptococcus pneumoniae non-mucoidal, small colony variant and determine the outcome of its co-culture with Haemophilus influenzae. Pathog Dis 2018; 76:5114576. [DOI: 10.1093/femspd/fty074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/30/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Alexandra Tikhomirova
- Research Centre for Infectious Disease, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- Australian Centre for Antimicrobial Resistance Ecology (ACARE), University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Claudia Trappetti
- Research Centre for Infectious Disease, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Alistair J Standish
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Yiwen Zhou
- Research Centre for Infectious Disease, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- Bioinformatics Hub, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - James Breen
- Bioinformatics Hub, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- Robinson Research Institute, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Stephen Pederson
- Bioinformatics Hub, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Peter S Zilm
- Department of Oral Microbiology, School of Dentistry, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - James C Paton
- Research Centre for Infectious Disease, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
| | - Stephen P Kidd
- Research Centre for Infectious Disease, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- School of Biological Sciences, University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
- Australian Centre for Antimicrobial Resistance Ecology (ACARE), University of Adelaide, North Terrace Campus, Adelaide, South Australia 5005, Australia
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19
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Cools F, Torfs E, Vanhoutte B, de Macedo MB, Bonofiglio L, Mollerach M, Maes L, Caljon G, Delputte P, Cappoen D, Cos P. Streptococcus pneumoniae galU gene mutation has a direct effect on biofilm growth, adherence and phagocytosis in vitro and pathogenicity in vivo. Pathog Dis 2018; 76:5078866. [DOI: 10.1093/femspd/fty069] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- F Cools
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - E Torfs
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - B Vanhoutte
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - M Bidart de Macedo
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - L Bonofiglio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética. Cátedra de Microbiología. Junín 956. Ciudad Autónoma de Buenos Aires, Argentina
| | - M Mollerach
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética. Cátedra de Microbiología. Junín 956. Ciudad Autónoma de Buenos Aires, Argentina
| | - L Maes
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - G Caljon
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Delputte
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - D Cappoen
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Cos
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
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20
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Nasher F, Förster S, Yildirim EC, Grandgirard D, Leib SL, Heller M, Hathaway LJ. Foreign peptide triggers boost in pneumococcal metabolism and growth. BMC Microbiol 2018; 18:23. [PMID: 29580217 PMCID: PMC5870813 DOI: 10.1186/s12866-018-1167-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 03/15/2018] [Indexed: 01/19/2023] Open
Abstract
Background Nonencapsulated Streptococcus pneumoniae bacteria are successful colonizers of the human nasopharynx and often possess genes aliB-like ORF 1 and 2 in place of capsule genes. AliB-like ORF 2 binds peptide FPPQSV, found in Prevotella species, resulting in enhanced colonization. How this response is mediated is so far unknown. Results Here we show that the peptide increases expression of genes involved in release of host carbohydrates, carbohydrate uptake and carbohydrate metabolism. In particular, the peptide increased expression of 1,5-anhydro-D-fructose reductase, a metabolic enzyme of an alternative starch and glycogen degrading pathway found in many organisms, in both transcriptomic and proteomic data. The peptide enhanced pneumococcal growth giving a competitive advantage to a strain with aliB-like ORF 2, over its mutant lacking the gene. Possession of aliB-like ORF 2 did not affect release of inflammatory cytokine CXCL8 from epithelial cells in culture and the nonencapsulated wild type strain was not able to establish disease or inflammation in an infant rat model of meningitis. Conclusions We propose that AliB-like ORF 2 confers an advantage in colonization by enhancing carbohydrate metabolism resulting in a boost in growth. This may explain the widespread presence of aliB-like ORF 2 in the nonencapsulated pneumococcal population in the human nasopharynx. Electronic supplementary material The online version of this article (10.1186/s12866-018-1167-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fauzy Nasher
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Sunniva Förster
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.,Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Efe C Yildirim
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland
| | - Denis Grandgirard
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland
| | - Stephen L Leib
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research, University of Bern, CH-3010, Bern, Switzerland
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Friedbühlstrasse 51, CH-3001, Bern, Switzerland.
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21
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Carvalho SM, Kloosterman TG, Manzoor I, Caldas J, Vinga S, Martinussen J, Saraiva LM, Kuipers OP, Neves AR. Interplay Between Capsule Expression and Uracil Metabolism in Streptococcus pneumoniae D39. Front Microbiol 2018; 9:321. [PMID: 29599757 PMCID: PMC5863508 DOI: 10.3389/fmicb.2018.00321] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
Pyrimidine nucleotides play an important role in the biosynthesis of activated nucleotide sugars (NDP-sugars). NDP-sugars are the precursors of structural polysaccharides in bacteria, including capsule, which is a major virulence factor of the human pathogen S. pneumoniae. In this work, we identified a spontaneous non-reversible mutant of strain D39 that displayed a non-producing capsule phenotype. Whole-genome sequencing analysis of this mutant revealed several non-synonymous single base modifications, including in genes of the de novo synthesis of pyrimidines and in the -10 box of capsule operon promoter (Pcps). By directed mutagenesis we showed that the point mutation in Pcps was solely responsible for the drastic decrease in capsule expression. We also demonstrated that D39 subjected to uracil deprivation shows increased biomass and decreased Pcps activity and capsule amounts. Importantly, Pcps expression is further decreased by mutating the first gene of the de novo synthesis of pyrimidines, carA. In contrast, the absence of uracil from the culture medium showed no effect on the spontaneous mutant strain. Co-cultivation of the wild-type and the mutant strain indicated a competitive advantage of the spontaneous mutant (non-producing capsule) in medium devoid of uracil. We propose a model in that uracil may act as a signal for the production of different capsule amounts in S. pneumoniae.
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Affiliation(s)
- Sandra M Carvalho
- Instituto de Tecnologia Química e Biológica NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tomas G Kloosterman
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Irfan Manzoor
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - José Caldas
- Instituto de Engenharia de Sistemas e Computadores, Investigação e Desenvolvimento (INESC-ID), Lisbon, Portugal
| | - Susana Vinga
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Jan Martinussen
- DTU Systems Biology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Lígia M Saraiva
- Instituto de Tecnologia Química e Biológica NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Ana R Neves
- Instituto de Tecnologia Química e Biológica NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
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22
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Mostowy RJ, Croucher NJ, De Maio N, Chewapreecha C, Salter SJ, Turner P, Aanensen DM, Bentley SD, Didelot X, Fraser C. Pneumococcal Capsule Synthesis Locus cps as Evolutionary Hotspot with Potential to Generate Novel Serotypes by Recombination. Mol Biol Evol 2017; 34:2537-2554. [PMID: 28595308 PMCID: PMC5850285 DOI: 10.1093/molbev/msx173] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Diversity of the polysaccharide capsule in Streptococcus pneumoniae-main surface antigen and the target of the currently used pneumococcal vaccines-constitutes a major obstacle in eliminating pneumococcal disease. Such diversity is genetically encoded by almost 100 variants of the capsule biosynthesis locus, cps. However, the evolutionary dynamics of the capsule remains not fully understood. Here, using genetic data from 4,519 bacterial isolates, we found cps to be an evolutionary hotspot with elevated substitution and recombination rates. These rates were a consequence of relaxed purifying selection and positive, diversifying selection acting at this locus, supporting the hypothesis that the capsule has an increased potential to generate novel diversity compared with the rest of the genome. Diversifying selection was particularly evident in the region of wzd/wze genes, which are known to regulate capsule expression and hence the bacterium's ability to cause disease. Using a novel, capsule-centered approach, we analyzed the evolutionary history of 12 major serogroups. Such analysis revealed their complex diversification scenarios, which were principally driven by recombination with other serogroups and other streptococci. Patterns of recombinational exchanges between serogroups could not be explained by serotype frequency alone, thus pointing to nonrandom associations between co-colonizing serotypes. Finally, we discovered a previously unobserved mosaic serotype 39X, which was confirmed to carry a viable and structurally novel capsule. Adding to previous discoveries of other mosaic capsules in densely sampled collections, these results emphasize the strong adaptive potential of the bacterium by its ability to generate novel antigenic diversity by recombination.
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Affiliation(s)
- Rafał J. Mostowy
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Nicholas J. Croucher
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Nicola De Maio
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Institute for Emerging Infections, Oxford Martin School, Oxford, United Kingdom
| | - Claire Chewapreecha
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- Bioinformatics and Systems Biology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
| | - Susannah J. Salter
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Paul Turner
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- Cambodia-Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
| | - David M. Aanensen
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- Centre for Genomic Pathogen Surveillance, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Stephen D. Bentley
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Xavier Didelot
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Christophe Fraser
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- Nuffield Department of Medicine, Li Ka Shing Centre for Health Information and Discovery, Oxford Big Data Institute, University of Oxford, Oxford, United Kingdom
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23
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Jang AY, Seo HS, Lin S, Chung GH, Kim HW, Lim S, Zhao L, Park IH, Lim JH, Kim KH. Molecular characterization of pneumococcal surface protein K, a potential pneumococcal vaccine antigen. Virulence 2017; 8:875-890. [PMID: 28059611 PMCID: PMC5626202 DOI: 10.1080/21505594.2016.1278334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/19/2016] [Accepted: 12/28/2016] [Indexed: 10/20/2022] Open
Abstract
The pneumococcal capsule is indispensable for pathogenesis in systemic infections; however, many pneumococcal diseases, including conjunctivitis, otitis media, and some systemic infections in immunocompromised patients, are caused by nonencapsulated Streptococcus pneumoniae (NESp). Null capsule clade 1 (NCC1), found in group 2 NESp, expresses pneumococcal surface protein K (PspK) and is becoming prevalent among pneumococcal organisms owing to the widespread use of pneumococcal conjugate vaccines. Despite its clinical importance, the molecular mechanisms underlying the prevalence of NCC1 have not been fully elucidated. Here, we investigated the role of the R3 domain of PspK in the epithelial cell adherence of NCC1. We found that the R3 domain of PspK mediated NCC1 adherence via its direct interaction with the epithelial surface protein annexin A2. Additionally, neutralization with purified recombinant PspK-R3 or rabbit anti-UD:R3 IgG inhibited binding of NESp to lung epithelial cells in vitro. Immunization with the 'repeat' domain of PspK-R3 or PspK-UD:R3 effectively elicited mucosal and systemic immune responses against PspK-R3 and provided protection against nasopharyngeal, lung, and middle ear colonization of NESp in mice. Additionally, we found that rabbit anti-UD:R3 IgG bound to PspC-R1 of the encapsulated TIGR4 strain and that UD:R3 immunization provided protection against nasopharyngeal and lung colonization of TIGR4 and deaths by TIGR4 and D39 in mice. Further studies using 68 pneumococcal clinical isolates showed that 79% of clinical isolates showed cross-reactivity to rabbit anti-UD:R3 IgG. About 87% of serotypes in the 13-valent pneumococcal conjugate vaccine (PCV) and 68% of non-vaccine serotypes were positive for cross-reactivity with rabbit anti-UD:R3 IgG. Thus, the R3 domain of PspK may be an effective vaccine candidate for both NESp and encapsulated Sp.
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Affiliation(s)
- A-Yeung Jang
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Biological Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Ho Seong Seo
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Shunmei Lin
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Gook-Hyun Chung
- Department of Biological Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Han Wool Kim
- Center for Vaccine Evaluation and Study, Medical Research Institute, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Sangyong Lim
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Lei Zhao
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - In Ho Park
- Center for Vaccine Evaluation and Study, Medical Research Institute, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Jae Hyang Lim
- Department of Microbiology, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Kyung-Hyo Kim
- Center for Vaccine Evaluation and Study, Medical Research Institute, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
- Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
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24
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Dimopoulou M, Claisse O, Dutilh L, Miot-Sertier C, Ballestra P, Lucas PM, Dols-Lafargue M. Molecular Cloning, Expression and Characterization of Oenococcus oeni Priming Glycosyltransferases. Mol Biotechnol 2017; 59:323-333. [PMID: 28667570 DOI: 10.1007/s12033-017-0021-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Oenococcus oeni is the main bacterial species that drives malolactic fermentation in wine. Most O. oeni strains produce capsular exopolysaccharides (EPS) that may contribute to protect them in the wine hostile environment. In O. oeni genome sequences, several genes are predicted to encode priming glycosyltransferases (pGTs). These enzymes are essential for EPS formation as they catalyze the first biosynthetic step through the formation of a phosphoanhydride bond between a hexose-1-phosphate and a lipid carrier undecaprenyl phosphate. In many microorganisms, mutations abolishing the pGT activity also abolish the EPS formation. We first made an in silico analysis of all the genes encoding putative pGT over 50 distinct O. oeni genome sequences. Two polyisoprenyl-phosphate-hexose-1-phosphate transferases, WoaA and WobA, and a glycosyltransferase (It3) were particularly examined for their topology and amino acid sequence. Several isoforms of these enzymes were then expressed in E. coli, and their substrate specificity was examined in vitro. The substrate specificity varied depending on the protein isoform examined, and several mutations were shown to abolish WobA activity but not EPS synthesis. Further analysis of woaA and wobA gene expression levels suggests that WoaA could replace the deficient WobA and maintain EPS formation.
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Affiliation(s)
- Maria Dimopoulou
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France
| | - Olivier Claisse
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France.,INRA, ISVV, USC 1366 Œnologie, 33140, Villenave d'Ornon, France
| | - Lucie Dutilh
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France
| | - Cécile Miot-Sertier
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France.,INRA, ISVV, USC 1366 Œnologie, 33140, Villenave d'Ornon, France
| | - Patricia Ballestra
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France
| | - Patrick M Lucas
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France
| | - Marguerite Dols-Lafargue
- Univ. Bordeaux, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France. .,Bordeaux INP, ISVV, EA 4577 Œnologie, 33140, Villenave d'Ornon, France.
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25
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Position of O-Acetylation within the Capsular Repeat Unit Impacts the Biological Properties of Pneumococcal Serotypes 33A and 33F. Infect Immun 2017; 85:IAI.00132-17. [PMID: 28438972 DOI: 10.1128/iai.00132-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/13/2017] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) produces many capsule types that differ in their abilities to evade host immune recognition. To explain these serotype-dependent protective capacities, many studies have investigated capsular thickness or the interaction of the capsule with complement proteins, but the effects of small chemical modifications of the capsule on its function have not been studied. One small chemical modification found frequently among pneumococcal capsules is O-acetylation. Pneumococcal serotype 33A has two membrane-bound O-acetyltransferase genes, wciG and wcjE A 33A wcjE-deficient variant, 33F, occurs naturally and is increasing in prevalence in the wake of widespread conjugate vaccine use, but no wciG-deficient variants have been reported. To study the biological consequence of the loss of O-acetylation, we created wciG-deficient variants in both serotypes 33A and 33F, which we named 33X1 (ΔwciG) and 33X2 (ΔwciG ΔwcjE). Serotypes 33X1 and 33X2 express novel capsule types based on serological and biochemical analyses. We found that loss of WcjE-mediated O-acetylation appears not to affect cell wall shielding, since serotypes 33A and 33F exhibit comparable nonspecific opsonophagocytic killing, biofilm production, and adhesion to nasopharyngeal cells, though serotype 33F survived short-term drying better than serotype 33A. Loss of WciG-mediated O-acetylation in serotypes 33X1 and 33X2, however, resulted in a phenotype resembling that of nonencapsulated strains: increased cell wall accessibility, increased nonspecific opsonophagocytic killing, enhanced biofilm formation, and increased adhesion to nasopharyngeal cells. We conclude that WciG-mediated, but not WcjE-mediated, O-acetylation is important for producing protective capsules in 33A and that small chemical changes to the capsule can drastically affect its biological properties.
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26
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Zeidan AA, Poulsen VK, Janzen T, Buldo P, Derkx PMF, Øregaard G, Neves AR. Polysaccharide production by lactic acid bacteria: from genes to industrial applications. FEMS Microbiol Rev 2017; 41:S168-S200. [DOI: 10.1093/femsre/fux017] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/29/2017] [Indexed: 01/14/2023] Open
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27
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Zheng Y, Zhang X, Wang X, Wang L, Zhang J, Yin Y. ComE, an Essential Response Regulator, Negatively Regulates the Expression of the Capsular Polysaccharide Locus and Attenuates the Bacterial Virulence in Streptococcus pneumoniae. Front Microbiol 2017; 8:277. [PMID: 28326061 PMCID: PMC5339220 DOI: 10.3389/fmicb.2017.00277] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/09/2017] [Indexed: 11/25/2022] Open
Abstract
The capsular polysaccharide (CPS) of Streptococcus pneumoniae is the main virulence factors required for effective colonization and invasive disease. The capacity to regulate CPS production at the transcriptional level is critical for the survival of S. pneumoniae in different host niches, but little is known about the transcription regulators of cps locus. In the present study, we isolated and identified the response regulator ComE, the master competence switch in transformation of S. pneumoniae, as a transcriptional regulator of cps locus by DNA affinity chromatography-pulldown, MALDI-TOF mass spectrometry (MS) and electrophoretic mobility shift assay (EMSA). Our results showed that phosphorylated mimetic of ComE (ComED58E) bound specifically to the cps locus prompter in vitro, and phosphorylated ComE negatively impacted both cps locus transcription and CPS production attenuating the pneumococcal virulence in vivo. Compared with D39-WT strain, D39ΔcomE mutant exhibited much thicker capsule, attenuated nasopharyngeal colonization and enhanced virulence in both pneumonia and bacteremia models of Balb/c mice. Furthermore, it was demonstrated that CSP-ComD/E competence system involved in regulating negatively the CPS production during the progress of transformation in D39. Our CSP1 induction experiment results showed that the expression of ComE in D39-WT strain increased powerfully by 120% after 10 min of CSP1 induction, but the CPS production in D39-WT strain decreased sharply by 67.1% after 15 min of CSP1 induction. However, the CPS production in D39ΔcomE mutant was almost constant during the whole stage of induction. Additionally, we found that extracellular glucose concentration could affect both the expression of ComE and CPS production of D39 in vitro. Taken together, for the first time, we report that ComE, as a transcriptional regulator of cps locus, plays an important role in transcriptional regulation of cps locus and capsular production level.
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Affiliation(s)
- Yuqiang Zheng
- Department of Medicine Laboratory, Childrens Hospital of Chongqing Medical University Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University Chongqing, China
| | - Xiaofang Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University Chongqing, China
| | - Libin Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University Chongqing, China
| | - Jinghui Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University Chongqing, China
| | - Yibing Yin
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University Chongqing, China
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28
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Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium. Vet Med Int 2017; 2017:8967618. [PMID: 28251016 PMCID: PMC5303596 DOI: 10.1155/2017/8967618] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/06/2016] [Accepted: 12/29/2016] [Indexed: 11/18/2022] Open
Abstract
The role of the P. multocida lipopolysaccharide (LPS) as a putative adhesin during the early stages of infection with this bacterium in the respiratory epithelium of rabbits was investigated. By light microscopy and double enzyme labeling of nasal septa tissues, the amount of bacteria attached to the respiratory epithelium and the amount of LPS present in goblet cells at different experimental times were estimated. Transmission electron microscopy (TEM) and LPS labeling with colloidal gold particles were also used to determine the exact location of LPS in the cells. Septa that were challenged with LPS of P. multocida and 30 minutes later with P. multocida showed more adherent bacteria and more severe lesions than the other treatments. Free LPS was observed in the lumen of the nasal septum, forming bilamellar structures and adhering to the cilia, microvilli, cytoplasmic membrane, and cytoplasm of epithelial ciliated and goblet cells. The above findings suggest that P. multocida LPS plays an important role in the process of bacterial adhesion and that it has the ability of being internalized into host cells.
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29
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Novick S, Shagan M, Blau K, Lifshitz S, Givon-Lavi N, Grossman N, Bodner L, Dagan R, Mizrachi Nebenzahl Y. Adhesion and invasion of Streptococcus pneumoniae to primary and secondary respiratory epithelial cells. Mol Med Rep 2016; 15:65-74. [PMID: 27922699 PMCID: PMC5355668 DOI: 10.3892/mmr.2016.5996] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/30/2016] [Indexed: 11/06/2022] Open
Abstract
The interaction between Streptococcus pneumoniae (S. pneumoniae) and the mucosal epithelial cells of its host is a prerequisite for pneumococcal disease development, yet the specificity of this interaction between different respiratory cells is not fully understood. In the present study, three areas were examined: i) The capability of the encapsulated S. pneumoniae serotype 3 strain (WU2) to adhere to and invade primary nasal‑derived epithelial cells in comparison to primary oral‑derived epithelial cells, A549 adenocarcinoma cells and BEAS‑2B viral transformed bronchial cells; ii) the capability of the unencapsulated 3.8DW strain (a WU2 derivative) to adhere to and invade the same cells over time; and iii) the ability of various genetically‑unrelated encapsulated and unencapsulated S. pneumoniae strains to adhere to and invade A549 lung epithelial cells. The results of the present study demonstrated that the encapsulated WU2 strain adhesion to and invasion of primary nasal epithelial cells was greatest, followed by BEAS‑2B, A549 and primary oral epithelial cells. By contrast, the unencapsulated 3.8‑DW strain invaded oral epithelial cells significantly more efficiently when compared to the nasal epithelial cells. In addition, unencapsulated S. pneumoniae strains adhered to and invaded the A459 cells significantly more efficiently than the encapsulated strains; this is consistent with previously published data. In conclusion, the findings presented in the current study indicated that the adhesion and invasion of the WU2 strain to primary nasal epithelial cells was more efficient compared with the other cultured respiratory epithelial cells tested, which corresponds to the natural course of S. pneumoniae infection and disease development. The target cell preference of unencapsulated strains was different from that of the encapsulated strains, which may be due to the exposure of cell wall proteins.
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Affiliation(s)
- Sara Novick
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Marilous Shagan
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Karin Blau
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Sarit Lifshitz
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Noga Givon-Lavi
- Pediatric Infectious Disease Unit, Soroka University Medical Center, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Nili Grossman
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Lipa Bodner
- Oral and Maxillofacial Surgery Unit, Soroka University Medical Center, Beer Sheva 84105, Israel
| | - Ron Dagan
- Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
| | - Yaffa Mizrachi Nebenzahl
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben‑Gurion University of The Negev, Beer Sheva 84101, Israel
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30
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Abstract
Pneumococcal infections continue to cause significant morbidity and mortality in patients throughout the world. This microorganism remains the most common bacterial cause of community-acquired pneumonia and is associated with a considerable burden of disease and health-care costs in both developed and developing countries. Emerging antibiotic resistance has been a concern because of its potential negative impact on the outcome of patients who receive standard antibiotic therapy. However, there have been substantial changes in the epidemiology of this pathogen in recent years, not least of which has been due to the use of pneumococcal conjugate vaccines in children, with subsequent herd protection in unvaccinated adults and children. Furthermore, much recent research has led to a better understanding of the virulence factors of this pathogen and their role in the pathogenesis of severe pneumococcal disease, including the cardiac complications, as well as the potential role of adjunctive therapy in the management of severely ill cases. This review will describe recent advances in our understanding of the epidemiology, virulence factors, and management of pneumococcal community-acquired pneumonia.
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Affiliation(s)
- Charles Feldman
- Charlotte Maxeke Johannesburg Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand Medical School, Johannesburg, South Africa
| | - Ronald Anderson
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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31
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Wen Z, Liu Y, Qu F, Zhang JR. Allelic Variation of the Capsule Promoter Diversifies Encapsulation and Virulence In Streptococcus pneumoniae. Sci Rep 2016; 6:30176. [PMID: 27465908 PMCID: PMC4964562 DOI: 10.1038/srep30176] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/28/2016] [Indexed: 02/05/2023] Open
Abstract
The polysaccharide capsule is the major virulence factor of Streptococcus pneumoniae (pneumococcus), a major human pathogen. The sequences in the promoter and coding regions of the capsule gene locus undergo extensive variations through the natural transformation-mediated horizontal gene transfer. The sequence variations in the coding region have led to at least 97 capsular serotypes. However, it remains unclear whether the sequence polymorphisms in the promoter region have any biological significance. In this study, we determined the sequences of the cps promoter region from 225 invasive pneumococcal isolates, and identified modular composition and remarkable inter-strain sequence variations in this region. The strain-to strain variations in the cps promoter are characterized by diversity in sequence and size, mosaic combinations of nucleotide polymorphisms and sequence modules, selective preservation of the sequence combinations, and promiscuous assortments of the sequences between the promoter and coding regions. Isogenic pneumococci carrying allelic variants of the cps promoter displayed significant differences in the transcription of the capsule genes, capsule production, adhesion to host epithelial cells, anti-phagocytosis and virulence in mouse bacteremia model. This study has thus indicated that the sequence polymorphisms in the cps promoter represent a novel mechanism for fine-tuning the level of encapsulation and virulence among S. pneumoniae strains.
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Affiliation(s)
- Zhensong Wen
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yanni Liu
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Fen Qu
- The Center of Clinical Diagnosis, 302 Hospital of PLA, Beijing, China
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China.,Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
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32
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Schoeniger JS, Hudson CM, Bent ZW, Sinha A, Williams KP. Experimental single-strain mobilomics reveals events that shape pathogen emergence. Nucleic Acids Res 2016; 44:6830-9. [PMID: 27378783 PMCID: PMC5001619 DOI: 10.1093/nar/gkw601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/22/2016] [Indexed: 11/29/2022] Open
Abstract
Virulence genes on mobile DNAs such as genomic islands (GIs) and plasmids promote bacterial pathogen emergence. Excision is an early step in GI mobilization, producing a circular GI and a deletion site in the chromosome; circular forms are also known for some bacterial insertion sequences (ISs). The recombinant sequence at the junctions of such circles and deletions can be detected sensitively in high-throughput sequencing data, using new computational methods that enable empirical discovery of mobile DNAs. For the rich mobilome of a hospital Klebsiella pneumoniae strain, circularization junctions (CJs) were detected for six GIs and seven IS types. Our methods revealed differential biology of multiple mobile DNAs, imprecision of integrases and transposases, and differential activity among identical IS copies for IS26, ISKpn18 and ISKpn21. Using the resistance of circular dsDNA molecules to exonuclease, internally calibrated with the native plasmids, showed that not all molecules bearing GI CJs were circular. Transpositions were also detected, revealing replicon preference (ISKpn18 prefers a conjugative IncA/C2 plasmid), local action (IS26), regional preferences, selection (against capsule synthesis) and IS polarity inversion. Efficient discovery and global characterization of numerous mobile elements per experiment improves accounting for the new gene combinations that arise in emerging pathogens.
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Affiliation(s)
- Joseph S Schoeniger
- Systems Biology Department, Sandia National Laboratories, Livermore, CA 94551, USA
| | - Corey M Hudson
- Systems Biology Department, Sandia National Laboratories, Livermore, CA 94551, USA
| | - Zachary W Bent
- Systems Biology Department, Sandia National Laboratories, Livermore, CA 94551, USA
| | - Anupama Sinha
- Systems Biology Department, Sandia National Laboratories, Livermore, CA 94551, USA
| | - Kelly P Williams
- Systems Biology Department, Sandia National Laboratories, Livermore, CA 94551, USA
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Ndlangisa KM, du Plessis M, Allam M, Wolter N, Mohale T, de Gouveia L, Birkhead M, Klugman KP, von Gottberg A. Two cases of serotypeable and non-serotypeable variants of Streptococcus pneumoniae detected simultaneously during invasive disease. BMC Microbiol 2016; 16:126. [PMID: 27342074 PMCID: PMC4921036 DOI: 10.1186/s12866-016-0745-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 06/15/2016] [Indexed: 01/13/2023] Open
Abstract
Background More than 94 serotypes of Streptococcus pneumoniae have been described to date, however the majority of disease is caused by approximately 20 serotypes. Some pneumococci do not react with commercially available antisera used for serotyping and are thus regarded as non-serotypeable (NT). These pneumococci are commonly isolated during carriage studies and very rarely cause invasive disease. Colonization may occur with more than one serotype however disease with more than one serotype is rarely detected. Thus there are limited data describing cases of pneumococcal disease caused by more than one isolate. Results In two cases of invasive pneumococcal disease in South Africa, a non-serotypeable and a serotypeable isolate were co-detected during routine serotyping. A serotype 1 and 18C isolate were each co-detected with a non-serotypeable isolate in 2009 (case A) and 2010 (case B), from cerebrospinal fluid and blood, respectively. Both patients were 10–14 years old. For case A, the serotypeable isolate could not be obtained due to low representation in the mixed culture. Using electron microscopy we confirmed lack of capsule for the non-serotypeable isolates. Comparison of the case A non-serotypeable isolate with a serotype 1 genome revealed only the presence of the rhamnose biosynthesis genes (rmlA, B, C and D) in the capsular locus, all other capsular genes were absent. Nonetheless it had a multilocus sequence type (ST) associated with serotype 1 (ST217 and ribosomal ST3462) and its core genome clustered with other ST217 isolates. The case B non-serotypeable isolate had all serotype 18C capsular genes except for variation in the wchA and wze genes, compared to the 18C isolate. Both case B isolates were ST9817 and their core genomes were identical. Conclusions The ability of pneumococci to alter capsule production is a potential vaccine escape mechanism and therefore non-serotypeable pneumococci should be monitored as such organisms may increase under vaccine pressure. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0745-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kedibone M Ndlangisa
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa. .,School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
| | - Mignon du Plessis
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Mushal Allam
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Nicole Wolter
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Thabo Mohale
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Linda de Gouveia
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Monica Birkhead
- Centre for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, and Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA, USA
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis (CRDM), National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
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Genomic analysis of nontypeable pneumococci causing invasive pneumococcal disease in South Africa, 2003-2013. BMC Genomics 2016; 17:470. [PMID: 27334470 PMCID: PMC4928513 DOI: 10.1186/s12864-016-2808-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/27/2016] [Indexed: 01/18/2023] Open
Abstract
Background The capsular polysaccharide is the principal virulence factor of Streptococcus pneumoniae and a target for current pneumococcal vaccines. However, some pathogenic pneumococci are serologically nontypeable [nontypeable pneumococci (NTPn)]. Due to their relative rarity, NTPn are poorly characterized, and, as such, limited data exist which describe these organisms. We aimed to describe disease and genotypically characterize NTPn causing invasive pneumococcal disease in South Africa. Results Isolates were detected through national, laboratory-based surveillance for invasive pneumococcal disease in South Africa and characterized by whole genome analysis. We predicted ancestral serotypes (serotypes from which NTPn may have originated) for Group I NTPn using multilocus sequence typing and capsular region sequence analyses. Antimicrobial resistance patterns and mutations potentially causing nontypeability were identified. From 2003–2013, 39 (0.1 %, 39/32,824) NTPn were reported. Twenty-two (56 %) had partial capsular genes (Group I) and 17 (44 %) had complete capsular deletion of which 15 had replacement by other genes (Group II). Seventy-nine percent (31/39) of our NTPn isolates were derived from encapsulated S. pneumoniae. Ancestral serotypes 1 (27 %, 6/22) and 8 (14 %, 3/22) were most prevalent, and 59 % (13/22) of ancestral serotypes were serotypes included in the 13-valent pneumococcal conjugate vaccine. We identified a variety of mutations within the capsular region of Group I NTPn, some of which may be responsible for the nontypeable phenotype. Nonsusceptibility to tetracycline and erythromycin was higher in NTPn than encapsulated S. pneumoniae. Conclusions NTPn are currently a rare cause of invasive pneumococcal disease in South Africa and represent a genetically diverse collection of isolates. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2808-x) contains supplementary material, which is available to authorized users.
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Abstract
Background Ninety-two Streptococcus pneumoniae serotypes have been described so far, but the pneumococcal conjugate vaccine introduced in the Brazilian basic vaccination schedule in 2010 covers only the ten most prevalent in the country. Pneumococcal serotype-shifting after massive immunization is a major concern and monitoring this phenomenon requires efficient and accessible serotyping methods. Pneumococcal serotyping based on antisera produced in animals is laborious and restricted to a few reference laboratories. Alternatively, molecular serotyping methods assess polymorphisms in the cps gene cluster, which encodes key enzymes for capsular polysaccharides synthesis in pneumococci. In one such approach, cps-RFLP, the PCR amplified cps loci are digested with an endonuclease, generating serotype-specific fingerprints on agarose gel electrophoresis. Methods In this work, in silico and in vitro approaches were combined to demonstrate that XhoII is the most discriminating endonuclease for cps-RFLP, and to build a database of serotype-specific fingerprints that accommodates the genetic diversity within the cps locus of 92 known pneumococci serotypes. Results The expected specificity of cps-RFLP using XhoII was 76% for serotyping and 100% for serogrouping. The database of cps-RFLP fingerprints was integrated to Molecular Serotyping Tool (MST), a previously published web-based software for molecular serotyping. In addition, 43 isolates representing 29 serotypes prevalent in the state of Minas Gerais, Brazil, from 2007 to 2013, were examined in vitro; 11 serotypes (nine serogroups) matched the respective in silico patterns calculated for reference strains. The remaining experimental patterns, despite their resemblance to their expected in silico patterns, did not reach the threshold of similarity score to be considered a match and were then added to the database. Conclusion The cps-RFLP method with XhoII outperformed the antisera-based and other molecular serotyping methods in regard of the expected specificity. In order to accommodate the genetic variability of the pneumococci cps loci, the database of cps-RFLP patterns will be progressively expanded to include new variant in vitro patterns. The cps-RFLP method with endonuclease XhoII coupled with MST for computer-assisted interpretation of results may represent a relevant contribution to the real time detection of changes in regional pneumococci population diversity in response to mass immunization programs.
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Mutations in pneumococcal cpsE generated via in vitro serial passaging reveal a potential mechanism of reduced encapsulation utilized by a conjunctival isolate. J Bacteriol 2015; 197:1781-91. [PMID: 25777672 DOI: 10.1128/jb.02602-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/05/2015] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED The polysaccharide capsule of Streptococcus pneumoniae is required for nasopharyngeal colonization and for invasive disease in the lungs, blood, and meninges. In contrast, the vast majority of conjunctival isolates are acapsular. The first serotype-specific gene in the capsule operon, cpsE, encodes the initiating glycosyltransferase and is one of the few serotype-specific genes that can tolerate null mutations. This report characterizes a spontaneously arising TIGR4 mutant exhibiting a reduced capsule, caused by a 6-nucleotide duplication in cpsE which results in duplication of Ala and Ile at positions 45 and 46. This strain (AI45dup) possessed more exposed phosphorylcholine and was hypersusceptible to C3 complement deposition compared to the wild type. Accordingly, the mutant was significantly better at forming abiotic biofilms and binding epithelial cells in vitro but was avirulent in a sepsis model. In vitro serial passaging of the wild-type strain failed to reproduce the AI45dup mutation but instead led to a variety of mutants with reduced capsule harboring single nucleotide polymorphisms (SNPs) in cpsE. A single passage in the sepsis model after high-dose inoculation readily yielded revertants of AI45dup with restored wild-type capsule level, but the majority of SNP alleles of cpsE could not revert, suppress, or bypass. Analysis of cpsE in conjunctival isolates revealed a strain with a single missense mutation at amino acid position 377, which was responsible for reduced encapsulation. This study supports the hypothesis that spontaneous, nonreverting mutations in cpsE serve as a form of adaptive mutation by providing a selective advantage to S. pneumoniae in niches where expression of capsule is detrimental. IMPORTANCE While the capsule of Streptococcus pneumoniae is required for colonization and invasive disease, most conjunctival isolates are acapsular by virtue of deletion of the entire capsular operon. We show that spontaneous acapsular mutants isolated in vitro harbor mostly nonrevertible single nucleotide polymorphism (SNP) null mutations in cpsE, encoding the initiating glycosyltransferase. From a small collection of acapsular conjunctival isolates, we identified one strain with a complete capsular operon but containing a SNP in cpsE that we show is responsible for the acapsular phenotype. We propose that acapsular conjunctival isolates may arise initially from such nonreverting SNP null mutations in cpsE, which can be followed later by deletion of portions or all of the cps operon.
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Hilty M, Wüthrich D, Salter SJ, Engel H, Campbell S, Sá-Leão R, de Lencastre H, Hermans P, Sadowy E, Turner P, Chewapreecha C, Diggle M, Pluschke G, McGee L, Eser ÖK, Low DE, Smith-Vaughan H, Endimiani A, Küffer M, Dupasquier M, Beaudoing E, Weber J, Bruggmann R, Hanage WP, Parkhill J, Hathaway LJ, Mühlemann K, Bentley SD. Global phylogenomic analysis of nonencapsulated Streptococcus pneumoniae reveals a deep-branching classic lineage that is distinct from multiple sporadic lineages. Genome Biol Evol 2014; 6:3281-94. [PMID: 25480686 PMCID: PMC4986459 DOI: 10.1093/gbe/evu263] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 01/08/2023] Open
Abstract
The surrounding capsule of Streptococcus pneumoniae has been identified as a major virulence factor and is targeted by pneumococcal conjugate vaccines (PCV). However, nonencapsulated S. pneumoniae (non-Ec-Sp) have also been isolated globally, mainly in carriage studies. It is unknown if non-Ec-Sp evolve sporadically, if they have high antibiotic nonsusceptiblity rates and a unique, specific gene content. Here, whole-genome sequencing of 131 non-Ec-Sp isolates sourced from 17 different locations around the world was performed. Results revealed a deep-branching classic lineage that is distinct from multiple sporadic lineages. The sporadic lineages clustered with a previously sequenced, global collection of encapsulated S. pneumoniae (Ec-Sp) isolates while the classic lineage is comprised mainly of the frequently identified multilocus sequences types (STs) ST344 (n = 39) and ST448 (n = 40). All ST344 and nine ST448 isolates had high nonsusceptiblity rates to β-lactams and other antimicrobials. Analysis of the accessory genome reveals that the classic non-Ec-Sp contained an increased number of mobile elements, than Ec-Sp and sporadic non-Ec-Sp. Performing adherence assays to human epithelial cells for selected classic and sporadic non-Ec-Sp revealed that the presence of a integrative conjugative element (ICE) results in increased adherence to human epithelial cells (P = 0.005). In contrast, sporadic non-Ec-Sp lacking the ICE had greater growth in vitro possibly resulting in improved fitness. In conclusion, non-Ec-Sp isolates from the classic lineage have evolved separately. They have spread globally, are well adapted to nasopharyngeal carriage and are able to coexist with Ec-Sp. Due to continued use of PCV, non-Ec-Sp may become more prevalent.
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Affiliation(s)
- Markus Hilty
- Institute for Infectious Diseases, University of Bern, Switzerland Department of Infectious Diseases, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Daniel Wüthrich
- Interfaculty Bioinformatics Unit, University of Bern, Switzerland Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | - Hansjürg Engel
- Institute for Infectious Diseases, University of Bern, Switzerland
| | - Samuel Campbell
- Institute for Infectious Diseases, University of Bern, Switzerland
| | - Raquel Sá-Leão
- Instituto de Tecnologia Química e Biológica, University of Lisbon, Portugal
| | - Hermínia de Lencastre
- Instituto de Tecnologia Química e Biológica, University of Lisbon, Portugal Laboratory of Microbiology and Infectious Diseases, The Rockefeller University
| | - Peter Hermans
- Laboratory of Pediatric Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Ewa Sadowy
- National Medicines Institute, Warsaw, Poland
| | - Paul Turner
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Claire Chewapreecha
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Mathew Diggle
- Clinical Microbiology Department, Queens Medical Centre, Nottingham, United Kingdom
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, University of Basel, Switzerland
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Georgia, Atlanta
| | - Özgen Köseoğlu Eser
- Department of Microbiology, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Donald E Low
- Mt Sinai Hospital & Public Health Laboratories, Toronto, Ontario, Canada
| | | | - Andrea Endimiani
- Institute for Infectious Diseases, University of Bern, Switzerland
| | - Marianne Küffer
- Institute for Infectious Diseases, University of Bern, Switzerland
| | | | | | - Johann Weber
- Centre for Integrative Genomics, University of Lausanne, Switzerland
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit, University of Bern, Switzerland Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - William P Hanage
- Department of Epidemiology, Center for Communicable Disease Dynamics, Harvard School of Public Health
| | | | - Lucy J Hathaway
- Institute for Infectious Diseases, University of Bern, Switzerland
| | - Kathrin Mühlemann
- Institute for Infectious Diseases, University of Bern, Switzerland Department of Infectious Diseases, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Stephen D Bentley
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom Department of Medicine, Addenbrookes Hospital, University of Cambridge, United Kingdom
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Ardissone S, Fumeaux C, Bergé M, Beaussart A, Théraulaz L, Radhakrishnan SK, Dufrêne YF, Viollier PH. Cell cycle constraints on capsulation and bacteriophage susceptibility. eLife 2014; 3. [PMID: 25421297 PMCID: PMC4241560 DOI: 10.7554/elife.03587] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 10/21/2014] [Indexed: 12/28/2022] Open
Abstract
Despite the crucial role of bacterial capsules in pathogenesis, it is still unknown if systemic cues such as the cell cycle can control capsule biogenesis. In this study, we show that the capsule of the synchronizable model bacterium Caulobacter crescentus is cell cycle regulated and we unearth a bacterial transglutaminase homolog, HvyA, as restriction factor that prevents capsulation in G1-phase cells. This capsule protects cells from infection by a generalized transducing Caulobacter phage (φCr30), and the loss of HvyA confers insensitivity towards φCr30. Control of capsulation during the cell cycle could serve as a simple means to prevent steric hindrance of flagellar motility or to ensure that phage-mediated genetic exchange happens before the onset of DNA replication. Moreover, the multi-layered regulatory circuitry directing HvyA expression to G1-phase is conserved during evolution, and HvyA orthologues from related Sinorhizobia can prevent capsulation in Caulobacter, indicating that alpha-proteobacteria have retained HvyA activity.
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Affiliation(s)
- Silvia Ardissone
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Coralie Fumeaux
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Matthieu Bergé
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Audrey Beaussart
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Laurence Théraulaz
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Sunish Kumar Radhakrishnan
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Yves F Dufrêne
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
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