1
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Rush JS, Zamakhaeva S, Murner NR, Deng P, Morris AJ, Kenner CW, Black I, Heiss C, Azadi P, Korotkov KV, Widmalm G, Korotkova N. Structure and mechanism of biosynthesis of Streptococcus mutans cell wall polysaccharide. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593426. [PMID: 38766245 PMCID: PMC11100793 DOI: 10.1101/2024.05.09.593426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Streptococcus mutans, the causative agent of human dental caries, expresses a cell wall attached Serotype c- specific Carbohydrate (SCC) that is critical for cell viability. SCC consists of a repeating →3)α-Rha(1→2)α-Rha(1→ polyrhamnose backbone, with glucose (Glc) side-chains and glycerol phosphate (GroP) decorations. This study reveals that SCC has one major and two minor Glc modifications. The major Glc modification, α-Glc, attached to position 2 of 3-rhamnose, is installed by SccN and SccM glycosyltransferases and is the site of the GroP addition. The minor Glc modifications are β-Glc linked to position 4 of 3-rhamnose installed by SccP and SccQ glycosyltransferases, and α-Glc attached to position 4 of 2-rhamnose installed by SccN working in tandem with an unknown enzyme. Both the major and the minor β-Glc modifications control bacterial morphology, but only the GroP and major Glc modifications are critical for biofilm formation.
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2
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Rahman MM, Zamakhaeva S, Rush JS, Chaton CT, Kenner CW, Hla YM, Tsui HCT, Winkler ME, Korotkov KV, Korotkova N. Disorder regulates homeostasis of extracytoplasmic proteins in streptococci. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.05.592596. [PMID: 38746434 PMCID: PMC11092751 DOI: 10.1101/2024.05.05.592596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Proteins harboring intrinsically disordered regions (IDRs) that lack regular secondary or tertiary structure are abundant across three domains of life. Here, using a deep neural network (DNN)-based method we predict IDRs in the extracytoplasmic proteome of Streptococcus mutans , Streptococcus pyogenes and Streptococcus pneumoniae . We identify a subset of the serine/threonine-rich IDRs and demonstrate that they are O -glycosylated with glucose by a GtrB-like glucosyltransferase in S. pyogenes and S. pneumoniae , and N-acetylgalactosamine by a Pgf-dependent mechanism in S. mutans . Loss of glycosylation leads to a defect in biofilm formation under ethanol-stressed conditions in S. mutans . We link this phenotype to a C-terminal IDR of peptidyl-prolyl isomerase PrsA which is protected from proteolytic degradation by O -glycosylation. The IDR length attenuates the efficiency of glycosylation and expression of PrsA. Taken together, our data support a model in which extracytoplasmic IDRs function as dynamic switches of protein homeostasis in streptococci.
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3
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Chamlagain M, Hu J, Sionov RV, Steinberg D. Anti-bacterial and anti-biofilm activities of arachidonic acid against the cariogenic bacterium Streptococcus mutans. Front Microbiol 2024; 15:1333274. [PMID: 38596377 PMCID: PMC11002910 DOI: 10.3389/fmicb.2024.1333274] [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: 11/04/2023] [Accepted: 02/16/2024] [Indexed: 04/11/2024] Open
Abstract
Streptococcus mutans is a Gram-positive, facultative anaerobic bacterium, which causes dental caries after forming biofilms on the tooth surface while producing organic acids that demineralize enamel and dentin. We observed that the polyunsaturated arachidonic acid (AA) (ω-6; 20:4) had an anti-bacterial activity against S. mutans, which prompted us to investigate its mechanism of action. The minimum inhibitory concentration (MIC) of AA on S. mutans was 25 μg/ml in the presence of 5% CO2, while it was reduced to 6.25-12.5 μg/ml in the absence of CO2 supplementation. The anti-bacterial action was due to a combination of bactericidal and bacteriostatic effects. The minimum biofilm inhibitory concentration (MBIC) was the same as the MIC, suggesting that part of the anti-biofilm effect was due to the anti-bacterial activity. Gene expression studies showed decreased expression of biofilm-related genes, suggesting that AA also has a specific anti-biofilm effect. Flow cytometric analyses using potentiometric DiOC2(3) dye, fluorescent efflux pump substrates, and live/dead SYTO 9/propidium iodide staining showed that AA leads to immediate membrane hyperpolarization, altered membrane transport and efflux pump activities, and increased membrane permeability with subsequent membrane perforation. High-resolution scanning electron microscopy (HR-SEM) showed remnants of burst bacteria. Furthermore, flow cytometric analysis using the redox probe 2',7'-dichlorofluorescein diacetate (DCFHDA) showed that AA acts as an antioxidant in a dose-dependent manner. α-Tocopherol, an antioxidant that terminates the radical chain, counteracted the anti-bacterial activity of AA, suggesting that oxidation of AA in bacteria leads to the production of cytotoxic radicals that contribute to bacterial growth arrest and death. Importantly, AA was not toxic to normal Vero epithelial cells even at 100 μg/ml, and it did not cause hemolysis of erythrocytes. In conclusion, our study shows that AA is a potentially safe drug that can be used to reduce the bacterial burden of cariogenic S. mutans.
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Affiliation(s)
- Manoj Chamlagain
- Institute of Biomedical and Oral Research (IBOR), The Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong SAR, China
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jieni Hu
- Institute of Biomedical and Oral Research (IBOR), The Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Ronit Vogt Sionov
- Institute of Biomedical and Oral Research (IBOR), The Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Doron Steinberg
- Institute of Biomedical and Oral Research (IBOR), The Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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4
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Kampff Z, van Sinderen D, Mahony J. Cell wall polysaccharides of streptococci: A genetic and structural perspective. Biotechnol Adv 2023; 69:108279. [PMID: 37913948 DOI: 10.1016/j.biotechadv.2023.108279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 10/04/2023] [Accepted: 10/28/2023] [Indexed: 11/03/2023]
Abstract
The Streptococcus genus comprises both commensal and pathogenic species. Additionally, Streptococcus thermophilus is exploited in fermented foods and in probiotic preparations. The ecological and metabolic diversity of members of this genus is matched by the complex range of cell wall polysaccharides that they present on their cell surfaces. These glycopolymers facilitate their interactions and environmental adaptation. Here, current knowledge on the genetic and compositional diversity of streptococcal cell wall polysaccharides including rhamnose-glucose polysaccharides, exopolysaccharides and teichoic acids is discussed. Furthermore, the species-specific cell wall polysaccharide combinations and specifically highlighting the presence of rhamnose-glucose polysaccharides in certain species, which are replaced by teichoic acids in other species. This review highlights model pathogenic and non-pathogenic species for which there is considerable information regarding cell wall polysaccharide composition, structure and genetic information. These serve as foundations to predict and focus research efforts in other streptococcal species for which such data currently does not exist.
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Affiliation(s)
- Zoe Kampff
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Douwe van Sinderen
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Jennifer Mahony
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
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5
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Guérin H, Quénée P, Palussière S, Courtin P, André G, Péchoux C, Costache V, Mahony J, van Sinderen D, Kulakauskas S, Chapot-Chartier MP. PBP2b Mutations Improve the Growth of Phage-Resistant Lactococcus cremoris Lacking Polysaccharide Pellicle. Appl Environ Microbiol 2023; 89:e0210322. [PMID: 37222606 PMCID: PMC10304956 DOI: 10.1128/aem.02103-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/01/2023] [Indexed: 05/25/2023] Open
Abstract
Lactococcus lactis and Lactococcus cremoris are Gram-positive lactic acid bacteria widely used as starter in milk fermentations. Lactococcal cells are covered with a polysaccharide pellicle (PSP) that was previously shown to act as the receptor for numerous bacteriophages of the Caudoviricetes class. Thus, mutant strains lacking PSP are phage resistant. However, because PSP is a key cell wall component, PSP-negative mutants exhibit dramatic alterations of cell shape and severe growth defects, which limit their technological value. In the present study, we isolated spontaneous mutants with improved growth, from L. cremoris PSP-negative mutants. These mutants grow at rates similar to the wild-type strain, and based on transmission electron microscopy analysis, they exhibit improved cell morphology compared to their parental PSP-negative mutants. In addition, the selected mutants maintain their phage resistance. Whole-genome sequencing of several such mutants showed that they carried a mutation in pbp2b, a gene encoding a penicillin-binding protein involved in peptidoglycan biosynthesis. Our results indicate that lowering or turning off PBP2b activity suppresses the requirement for PSP and ameliorates substantially bacterial fitness and morphology. IMPORTANCE Lactococcus lactis and Lactococcus cremoris are widely used in the dairy industry as a starter culture. As such, they are consistently challenged by bacteriophage infections which may result in reduced or failed milk acidification with associated economic losses. Bacteriophage infection starts with the recognition of a receptor at the cell surface, which was shown to be a cell wall polysaccharide (the polysaccharide pellicle [PSP]) for the majority of lactococcal phages. Lactococcal mutants devoid of PSP exhibit phage resistance but also reduced fitness, since their morphology and division are severely impaired. Here, we isolated spontaneous, food-grade non-PSP-producing L. cremoris mutants resistant to bacteriophage infection with a restored fitness. This study provides an approach to isolate non-GMO phage-resistant L. cremoris and L. lactis strains, which can be applied to strains with technological functionalities. Also, our results highlight for the first time the link between peptidoglycan and cell wall polysaccharide biosynthesis.
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Affiliation(s)
- Hugo Guérin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Pascal Quénée
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Simon Palussière
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Pascal Courtin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Gwenaëlle André
- Université Paris-Saclay, INRAE, MaIAGE, Jouy-en-Josas, France
| | - Christine Péchoux
- Université Paris-Saclay, INRAE, GABI, Jouy-en-Josas, France
- MIMA2 Imaging Core Facility, Microscopie et Imagerie des Microorganismes, Animaux et Aliments, INRAE, Jouy-en-Josas, France
| | - Vlad Costache
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
- MIMA2 Imaging Core Facility, Microscopie et Imagerie des Microorganismes, Animaux et Aliments, INRAE, Jouy-en-Josas, France
| | - Jennifer Mahony
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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6
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Du J, Huang S, Wu M, Chen S, Zhou W, Zhan L, Huang X. Dlt operon regulates physiological function and cariogenic virulence in Streptococcus mutans. Future Microbiol 2023; 18:225-233. [PMID: 37097048 DOI: 10.2217/fmb-2022-0165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
Streptococcus mutans is one of the major cariogenic pathogens in the oral cavity. The dlt operon is responsible for the process of D-alanylation of lipoteichoic acid and is related to the virulence of S. mutans. The dlt operon contributes to the adhesion, biofilm formation, stress response, interspecies competitiveness and autolysis of S. mutans. In addition, we have summarized the possible regulatory networks of the dlt operon. This review highlights the significant role of the dlt operon in S. mutans and provides new ideas for ecological caries prevention.
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Affiliation(s)
- Jingyun Du
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Shan Huang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Minjing Wu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
- Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Shuai Chen
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Wen Zhou
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Ling Zhan
- Division of Pediatric Dentistry, Department of Orofacial Sciences, Department of Preventive & Restorative Dental Sciences, University of California, San Francisco, CA, USA
| | - Xiaojing Huang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College & University, School & Hospital of Stomatology, Fujian Medical University, Fuzhou, China
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7
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Brogan AP, Rudner DZ. Regulation of peptidoglycan hydrolases: localization, abundance, and activity. Curr Opin Microbiol 2023; 72:102279. [PMID: 36812681 PMCID: PMC10031507 DOI: 10.1016/j.mib.2023.102279] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 02/22/2023]
Abstract
Most bacteria are surrounded by a cell wall composed of peptidoglycan (PG) that specifies shape and protects the cell from osmotic rupture. Growth, division, and morphogenesis are intimately linked to the synthesis of this exoskeleton but also its hydrolysis. The enzymes that cleave the PG meshwork require careful control to prevent aberrant hydrolysis and loss of envelope integrity. Bacteria employ diverse mechanisms to control the activity, localization, and abundance of these potentially autolytic enzymes. Here, we discuss four examples of how cells integrate these control mechanisms to finely tune cell wall hydrolysis. We highlight recent advances and exciting avenues for future investigation.
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Affiliation(s)
- Anna P Brogan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
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8
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Nagasawa R, Nomura N, Obana N. Identification of a Novel Gene Involved in Cell-to-cell Communication-induced Cell Death and eDNA Production in Streptococcus mutans. Microbes Environ 2023; 38:n/a. [PMID: 37302844 DOI: 10.1264/jsme2.me22085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023] Open
Abstract
Streptococcus mutans is a major caries-causing bacterium that forms firmly attached biofilms on tooth surfaces. Biofilm formation by S. mutans consists of polysaccharide-dependent and polysaccharide-independent processes. Among polysaccharide-independent processes, extracellular DNA (eDNA) mediates the initial attachment of cells to surfaces. We previously reported that the secreted peptide signal, competence-stimulating peptide (CSP) induced cell death in a subpopulation of cells, leading to autolysis-mediated eDNA release. The autolysin gene lytF, the expression of which is stimulated by CSP, has been shown to mediate CSP-dependent cell death, while cell death was not entirely abolished in the lytF deletion mutant, indicating the involvement of other factors. To identify novel genes involved in CSP-dependent cell death, we herein compared transcriptomes between live and dead cells derived from an isogenic population. The results obtained revealed the accumulation of several mRNAs in dead cells. The deletion of SMU_1553c, a putative bacteriocin gene, resulted in significant reductions in CSP-induced cell death and eDNA production levels from those in the parental strain. Moreover, in the double mutant strain of lytF and SMU_1553c, cell death and eDNA production in response to synthetic CSP were completely abolished under both planktonic and biofilm conditions. These results indicate that SMU_1553c is a novel cell death-related factor that contributes to CSP-dependent cell death and eDNA production.
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Affiliation(s)
- Ryo Nagasawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba
- Microbiology Research Center for Sustainability, University of Tsukuba
| | - Nozomu Obana
- Microbiology Research Center for Sustainability, University of Tsukuba
- Faculty of Medicine, Transborder Medical Research Center, University of Tsukuba
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9
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Guérin H, Kulakauskas S, Chapot-Chartier MP. Structural variations and roles of rhamnose-rich cell wall polysaccharides in Gram-positive bacteria. J Biol Chem 2022; 298:102488. [PMID: 36113580 PMCID: PMC9574508 DOI: 10.1016/j.jbc.2022.102488] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/17/2022] Open
Abstract
Rhamnose-rich cell wall polysaccharides (Rha-CWPSs) have emerged as crucial cell wall components of numerous Gram-positive, ovoid-shaped bacteria—including streptococci, enterococci, and lactococci—of which many are of clinical or biotechnological importance. Rha-CWPS are composed of a conserved polyrhamnose backbone with side-chain substituents of variable size and structure. Because these substituents contain phosphate groups, Rha-CWPS can also be classified as polyanionic glycopolymers, similar to wall teichoic acids, of which they appear to be functional homologs. Recent advances have highlighted the critical role of these side-chain substituents in bacterial cell growth and division, as well as in specific interactions between bacteria and infecting bacteriophages or eukaryotic hosts. Here, we review the current state of knowledge on the structure and biosynthesis of Rha-CWPS in several ovoid-shaped bacterial species. We emphasize the role played by multicomponent transmembrane glycosylation systems in the addition of side-chain substituents of various sizes as extracytoplasmic modifications of the polyrhamnose backbone. We provide an overview of the contribution of Rha-CWPS to cell wall architecture and biogenesis and discuss current hypotheses regarding their importance in the cell division process. Finally, we sum up the critical roles that Rha-CWPS can play as bacteriophage receptors or in escaping host defenses, roles that are mediated mainly through their side-chain substituents. From an applied perspective, increased knowledge of Rha-CWPS can lead to advancements in strategies for preventing phage infection of lactococci and streptococci in food fermentation and for combating pathogenic streptococci and enterococci.
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Affiliation(s)
- Hugo Guérin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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10
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Hsu CC, Hsu RB, Oon XH, Chen YT, Chen JW, Hsu CH, Kuo YM, Shih YH, Chia JS, Jung CJ. Streptococcus mutans PrsA mediates AtlA secretion contributing to extracellular DNA release and biofilm formation in the pathogenesis of infective endocarditis. Virulence 2022; 13:1379-1392. [PMID: 35876630 PMCID: PMC9377233 DOI: 10.1080/21505594.2022.2105351] [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: 11/08/2022] Open
Abstract
The role of secretion chaperone-regulated virulence proteins in the pathogenesis of infective endocarditis (IE) induced by viridans streptococci such as Streptococcus mutans is unclear. In this study, we investigated the contribution of the foldase protein PrsA, a putative parvulin-type peptidyl-prolyl isomerase, to the pathogenesis of S. mutans-induced IE. We found that a prsA-deficient strain had reduced virulence in terms of formation of vegetation on damaged heart valves, as well as reduced autolysis activity, eDNA release and biofilm formation capacity. The secretion and surface exposure of AtlA in vitro was reduced in the prsA-deficient mutant strain, and complementation of recombinant AtlA in the culture medium restored a wild type biofilm phenotype of the prsA-deficient mutant strain. This result suggests that secretion and surface localization of AtlA is regulated by PrsA during biofilm formation. Together, these results demonstrate that S. mutans PrsA could regulate AtlA-mediated eDNA release to contribute to biofilm formation in the pathogenesis of IE.
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Affiliation(s)
- Chih-Chieh Hsu
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan
| | - Ron-Bin Hsu
- Department of Surgery, Division of Cardiovascular Surgery, National Taiwan University Hospital , College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Xoong-Harng Oon
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ya-Tang Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan
| | - Jeng-Wei Chen
- Department of Surgery, Division of Cardiovascular Surgery, National Taiwan University Hospital , College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Che-Hao Hsu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan
| | - Yu-Min Kuo
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Division of Allergy, Immunology, and Rheumatology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yi-Hsien Shih
- Department of Dermatology, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan.,Department of Dermatology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jean-San Chia
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chiau-Jing Jung
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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11
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Flores-Kim J, Dobihal GS, Bernhardt TG, Rudner DZ. WhyD tailors surface polymers to prevent premature bacteriolysis and direct cell elongation in Streptococcus pneumoniae. eLife 2022; 11:76392. [PMID: 35593695 PMCID: PMC9208761 DOI: 10.7554/elife.76392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/19/2022] [Indexed: 11/30/2022] Open
Abstract
Penicillin and related antibiotics disrupt cell wall synthesis in bacteria causing the downstream misactivation of cell wall hydrolases called autolysins to induce cell lysis. Despite the clinical importance of this phenomenon, little is known about the factors that control autolysins and how penicillins subvert this regulation to kill cells. In the pathogen Streptococcus pneumoniae (Sp), LytA is the major autolysin responsible for penicillin-induced bacteriolysis. We recently discovered that penicillin treatment of Sp causes a dramatic shift in surface polymer biogenesis in which cell wall-anchored teichoic acids (WTAs) increase in abundance at the expense of lipid-linked teichoic acids (LTAs). Because LytA binds to both species of teichoic acids, this change recruits the enzyme to its substrate where it cleaves the cell wall and elicits lysis. In this report, we identify WhyD (SPD_0880) as a new factor that controls the level of WTAs in Sp cells to prevent LytA misactivation and lysis during exponential growth . We show that WhyD is a WTA hydrolase that restricts the WTA content of the wall to areas adjacent to active peptidoglycan (PG) synthesis. Our results support a model in which the WTA tailoring activity of WhyD during exponential growth directs PG remodeling activity required for proper cell elongation in addition to preventing autolysis by LytA.
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Affiliation(s)
- Josué Flores-Kim
- Department of Microbiology, Harvard Medical School, Boston, United States
| | | | - Thomas G Bernhardt
- Department of Microbiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, United States
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12
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PplD is a de-N-acetylase of the cell wall linkage unit of streptococcal rhamnopolysaccharides. Nat Commun 2022; 13:590. [PMID: 35105886 PMCID: PMC8807736 DOI: 10.1038/s41467-022-28257-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/07/2022] [Indexed: 02/06/2023] Open
Abstract
The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates that PplD performs catalysis via a modified acid/base mechanism. Genetic surveys in silico together with functional analysis indicate that PplD homologs deacetylate the polysaccharide linkage in many streptococcal species. We further demonstrate that introduction of positive charges to the cell wall by GlcNAc deacetylation protects GAS against host cationic antimicrobial proteins.
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13
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Pan T, Guan J, Li Y, Sun B. LcpB Is a Pyrophosphatase Responsible for Wall Teichoic Acid Synthesis and Virulence in Staphylococcus aureus Clinical Isolate ST59. Front Microbiol 2021; 12:788500. [PMID: 34975809 PMCID: PMC8716876 DOI: 10.3389/fmicb.2021.788500] [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: 10/02/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes severe pandemics primarily consisting of skin and soft tissue infections. However, the underlying pathomechanisms of the bacterium are yet to fully understood. The present study identifies LcpB protein, which belongs to the LytR-A-Psr (LCP) family, is crucial for cell wall synthesis and virulence in S. aureus. The findings revealed that LcpB is a pyrophosphatase responsible for wall teichoic acid synthesis. The results also showed that LcpB regulates enzyme activity through specific key arginine sites in its LCP domain. Furthermore, knockout of lcpB in the CA-MRSA isolate ST59 resulted in enhanced hemolytic activity, enlarged of abscesses, and increased leukocyte infiltration. Meanwhile, we also found that LcpB regulates virulence in agr-independent manner and the key sites for pyrophosphatase of LcpB play critical roles in regulating the virulence. In addition, the results showed that the role of LcpB was different between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). This study therefore highlights the dual role of LcpB in cell wall synthesis and regulation of virulence. These insights on the underlying molecular mechanisms can thus guide the development of novel anti-infective strategies.
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Affiliation(s)
- Ting Pan
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jing Guan
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yujie Li
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
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Briggs NS, Bruce KE, Naskar S, Winkler ME, Roper DI. The Pneumococcal Divisome: Dynamic Control of Streptococcus pneumoniae Cell Division. Front Microbiol 2021; 12:737396. [PMID: 34737730 PMCID: PMC8563077 DOI: 10.3389/fmicb.2021.737396] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Cell division in Streptococcus pneumoniae (pneumococcus) is performed and regulated by a protein complex consisting of at least 14 different protein elements; known as the divisome. Recent findings have advanced our understanding of the molecular events surrounding this process and have provided new understanding of the mechanisms that occur during the division of pneumococcus. This review will provide an overview of the key protein complexes and how they are involved in cell division. We will discuss the interaction of proteins in the divisome complex that underpin the control mechanisms for cell division and cell wall synthesis and remodelling that are required in S. pneumoniae, including the involvement of virulence factors and capsular polysaccharides.
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Affiliation(s)
- Nicholas S. Briggs
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Kevin E. Bruce
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Souvik Naskar
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Malcolm E. Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - David I. Roper
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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15
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Dresen M, Rohde M, Arenas J, de Greeff A, Nerlich A, Valentin‐Weigand P. Identification and characterization of the cell division protein MapZ from Streptococcus suis. Microbiologyopen 2021; 10:e1234. [PMID: 34713609 PMCID: PMC8501179 DOI: 10.1002/mbo3.1234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/26/2021] [Indexed: 11/11/2022] Open
Abstract
Streptococcus suis, an emerging zoonotic pathogen, causes invasive diseases in pigs, including sepsis, meningitis, endocarditis, pneumonia, and arthritis. Importantly, similar pathologies are reported in human S. suis infections. In previous work, the locus SSU0375 of S. suis strain P1.7 had been identified as a conditionally essential gene by intrathecal experimental infection of pigs with a transposon library of S. suis. This study aimed to identify the function of the corresponding gene product. Bioinformatics analysis and homology modeling revealed sequence and structural homologies with the Streptococcus pneumoniae mid-cell-anchored protein Z (MapZ) that is involved in cell division in different bacterial species. Indeed, depletion of this locus in S. suis strain 10 revealed a growth defect as compared to the wild type. Electron microscopy analysis of the corresponding mutant demonstrated morphological growth defects as compared to the wild-type strain, including an irregular cell shape and size as well as mispositioned division septa. Light microscopy and subsequent quantitative image analysis confirmed these morphological alterations. In the genetic rescue strain, the wild-type phenotype was completely restored. In summary, we proposed that SSU0375 or the corresponding locus in strain 10 encode for a S. suis MapZ homolog that guides septum positioning as evidenced for other members of the Streptococci family.
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Affiliation(s)
- Muriel Dresen
- Institute for MicrobiologyCenter for Infection MedicineUniversity of Veterinary Medicine HannoverHannoverGermany
| | - Manfred Rohde
- Central Facility for MicroscopyHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Jesús Arenas
- Unit of Microbiology and ImmunologyFaculty of VeterinaryUniversity of ZaragozaZaragozaSpain
| | - Astrid de Greeff
- Wageningen Bioveterinary ResearchPart of Wageningen University and ResearchLelystadThe Netherlands
| | - Andreas Nerlich
- Institute for MicrobiologyCenter for Infection MedicineUniversity of Veterinary Medicine HannoverHannoverGermany
- Veterinary Centre for Resistance ResearchFreie Universität BerlinBerlinGermany
| | - Peter Valentin‐Weigand
- Institute for MicrobiologyCenter for Infection MedicineUniversity of Veterinary Medicine HannoverHannoverGermany
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16
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Abstract
Extracellular peptidoglycan-linked polysaccharide modifications mediate cell morphology, division, and autolysis in some Gram-positive bacterial pathogens. A new study shows that the degree and location of a specific modification controls peptidoglycan hydrolysis and placement of the axis of cell division.
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17
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King H, Ajay Castro S, Pohane AA, Scholte CM, Fischetti VA, Korotkova N, Nelson DC, Dorfmueller HC. Molecular basis for recognition of the Group A Carbohydrate backbone by the PlyC streptococcal bacteriophage endolysin. Biochem J 2021; 478:2385-2397. [PMID: 34096588 PMCID: PMC8555655 DOI: 10.1042/bcj20210158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/25/2021] [Accepted: 06/07/2021] [Indexed: 11/17/2022]
Abstract
Endolysins are peptidoglycan (PG) hydrolases that function as part of the bacteriophage (phage) lytic system to release progeny phage at the end of a replication cycle. Notably, endolysins alone can produce lysis without phage infection, which offers an attractive alternative to traditional antibiotics. Endolysins from phage that infect Gram-positive bacterial hosts contain at least one enzymatically active domain (EAD) responsible for hydrolysis of PG bonds and a cell wall binding domain (CBD) that binds a cell wall epitope, such as a surface carbohydrate, providing some degree of specificity for the endolysin. Whilst the EADs typically cluster into conserved mechanistic classes with well-defined active sites, relatively little is known about the nature of the CBDs and only a few binding epitopes for CBDs have been elucidated. The major cell wall components of many streptococci are the polysaccharides that contain the polyrhamnose (pRha) backbone modified with species-specific and serotype-specific glycosyl side chains. In this report, using molecular genetics, microscopy, flow cytometry and lytic activity assays, we demonstrate the interaction of PlyCB, the CBD subunit of the streptococcal PlyC endolysin, with the pRha backbone of the cell wall polysaccharides, Group A Carbohydrate (GAC) and serotype c-specific carbohydrate (SCC) expressed by the Group A Streptococcus and Streptococcus mutans, respectively.
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Affiliation(s)
- Harley King
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Sowmya Ajay Castro
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Amol Arunrao Pohane
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, U.S.A
| | - Cynthia M Scholte
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Vincent A Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York, NY, U.S.A
| | - Natalia Korotkova
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, U.S.A
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, U.S.A
| | - Daniel C Nelson
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, U.K
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