1
|
Hart MT, Rom JS, Le Breton Y, Hause LL, Belew AT, El-Sayed NM, McIver KS. The Streptococcus pyogenes stand-alone regulator RofA exhibits characteristics of a PRD-containing virulence regulator. Infect Immun 2024; 92:e0008324. [PMID: 38712951 PMCID: PMC11237776 DOI: 10.1128/iai.00083-24] [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: 02/23/2024] [Accepted: 04/09/2024] [Indexed: 05/08/2024] Open
Abstract
Streptococcus pyogenes [group A streptococcus (GAS)] is a human pathogen capable of infecting diverse tissues. To successfully infect these sites, GAS must detect available nutrients and adapt accordingly. The phosphoenolpyruvate transferase system (PTS) mediates carbohydrate uptake and metabolic gene regulation to adapt to the nutritional environment. Regulation by the PTS can occur through phosphorylation of transcriptional regulators at conserved PTS-regulatory domains (PRDs). GAS has several PRD-containing stand-alone regulators with regulons encoding both metabolic genes and virulence factors [PRD-containing virulence regulators (PCVRs)]. One is RofA, which regulates the expression of virulence genes in multiple GAS serotypes. It was hypothesized that RofA is phosphorylated by the PTS in response to carbohydrate levels to coordinate virulence gene expression. In this study, the RofA regulon of M1T1 strain 5448 was determined using RNA sequencing. Two operons were consistently differentially expressed across growth in the absence of RofA; the pilus operon was downregulated, and the capsule operon was upregulated. This correlated with increased capsule production and decreased adherence to keratinocytes. Purified RofA-His was phosphorylated in vitro by PTS proteins EI and HPr, and phosphorylated RofA-FLAG was detected in vivo when GAS was grown in low-glucose C medium. Phosphorylated RofA was not observed when C medium was supplemented 10-fold with glucose. Mutations of select histidine residues within the putative PRDs contributed to the in vivo phosphorylation of RofA, although phosphorylation of RofA was still observed, suggesting other phosphorylation sites exist in the protein. Together, these findings support the hypothesis that RofA is a PCVR that may couple sugar metabolism with virulence regulation.
Collapse
Affiliation(s)
- Meaghan T Hart
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
| | - Joseph S Rom
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
| | - Yoann Le Breton
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
| | - Lara L Hause
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
| | - Ashton T Belew
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, USA
| | - Najib M El-Sayed
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, USA
| | - Kevin S McIver
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, College Park, Maryland, USA
| |
Collapse
|
2
|
Xu Y, Liang X, Hyun CG. Isolation, Characterization, Genome Annotation, and Evaluation of Hyaluronidase Inhibitory Activity in Secondary Metabolites of Brevibacillus sp. JNUCC 41: A Comprehensive Analysis through Molecular Docking and Molecular Dynamics Simulation. Int J Mol Sci 2024; 25:4611. [PMID: 38731830 PMCID: PMC11083829 DOI: 10.3390/ijms25094611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
Brevibacillus sp. JNUCC 41, characterized as a plant-growth-promoting rhizobacterium (PGPR), actively participates in lipid metabolism and biocontrol based on gene analysis. This study aimed to investigate the crucial secondary metabolites in biological metabolism; fermentation, extraction, and isolation were performed, revealing that methyl indole-3-acetate showed the best hyaluronidase (HAase) inhibitory activity (IC50: 343.9 μM). Molecular docking results further revealed that the compound forms hydrogen bonds with the residues Tyr-75 and Tyr-247 of HAase (binding energy: -6.4 kcal/mol). Molecular dynamics (MD) simulations demonstrated that the compound predominantly binds to HAase via hydrogen bonding (MM-PBSA binding energy: -24.9 kcal/mol) and exhibits good stability. The residues Tyr-247 and Tyr-202, pivotal for binding in docking, were also confirmed via MD simulations. This study suggests that methyl indole-3-acetate holds potential applications in anti-inflammatory and anti-aging treatments.
Collapse
Affiliation(s)
| | | | - Chang-Gu Hyun
- Department of Beauty and Cosmetology, Jeju Inside Agency and Cosmetic Science Center, Jeju National University, Jeju 63243, Republic of Korea; (Y.X.); (X.L.)
| |
Collapse
|
3
|
Vandana, Das S. Genetic regulation, biosynthesis and applications of extracellular polysaccharides of the biofilm matrix of bacteria. Carbohydr Polym 2022; 291:119536. [DOI: 10.1016/j.carbpol.2022.119536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 11/02/2022]
|
4
|
Jiang X, Lin A, Li S, Shi Y, Zhou F, Felix Gomez GG, Gregory RL, Zhang C, Chen S, Huang R. Effects of artificial honey and epigallocatechin-3-gallate on streptococcus pyogenes. BMC Microbiol 2022; 22:207. [PMID: 36028794 PMCID: PMC9419396 DOI: 10.1186/s12866-022-02611-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 08/04/2022] [Indexed: 12/01/2022] Open
Abstract
Background Streptococcus pyogenes is an important global human pathogen that causes pharyngitis, and antibacterial therapy has become an important part of the overall therapy for pharyngitis. As natural derivatives, honey and green tea are often recommended for patients with pharyngitis in traditional Chinese medicine without experimental theoretical basis on wether the combined effect of honey and green tea on pharyngitis is better than they alone. The aims of this study were to explore the effects of artificial honey (AH) and epigallocatechin-3-gallate (EGCG) on S. pyogenes and elucidate the possible mechanisms, which were investigated using MIC (the minimum inhibitory concentration), FIC (fractional inhibitory concentration) index, growth pattern, biofilm formation and RT-qPCR. Results The MIC of AH on S. pyogenes was 12.5% (v/v) and the MIC of EGCG was 1250 μg/ml. The FIC index of AH and EGCG was 0.5. The planktonic cell growth, growth pattern and biofilm formation assays showed that AH and EGCG mixture had stronger inhibitory effect on S. pyogenes than they alone. RT-qPCR confirmed that the expression of hasA and luxS gene were inhibited by AH and EGCG mixture. Conclusions AH and EGCG mixture can inhibit the planktonic cell growth, biofilm formation and some virulence genes expression of S. pyogenes, better than they alone. The combination of honey and green tea have the potential to treat pharyngitis as natural derivatives, avoiding drug resistance and double infection.
Collapse
Affiliation(s)
- Xiaoge Jiang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - An Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Shijia Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yangyang Shi
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Endodontic Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Fangjie Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Endodontic Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | | | - Richard L Gregory
- Department of Oral Biology, School of Dentistry, Indiana University, Indianapolis, USA
| | - Chaoliang Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Song Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Ruijie Huang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Oral Biology, School of Dentistry, Indiana University, Indianapolis, USA.
| |
Collapse
|
5
|
Banerji R, Iyer P, Saroj SD. Spermidine enhances the survival of Streptococcus pyogenes M3 under oxidative stress. Mol Oral Microbiol 2022; 37:53-62. [PMID: 34994090 DOI: 10.1111/omi.12360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 12/17/2022]
Abstract
Streptococcus pyogenes, a host-restricted gram-positive pathogen during infection, initially adheres to the epithelia of the nasopharynx and respiratory tract of the human host, followed by disseminating to other organs and evading the host immune system. Upon phagocytosis, S. pyogenes encounters oxidative stress inside the macrophages. The role of polyamines in regulating various physiological functions including stress resistance in bacteria has been reported widely. Since S. pyogenes lacks the machinery for the biosynthesis of polyamines, the study aimed to understand the role of extracellular polyamines in the survival of S. pyogenes under oxidative stress environments. S. pyogenes being a catalase-negative organism, we report that its survival within the macrophages and H2 O2 is enhanced by the presence of spermidine. The increased survival can be attributed to the upregulation of oxidative stress response genes such as sodM, npx, and mtsABC. In addition, spermidine influences the upregulation of virulence factors such as sagA, slo, and hasA. Also, spermidine leads to a decrease in hydrophobicity of the cell membrane and an increase in hyaluronic acid. This study suggests a role for extracellular spermidine in the survival of S. pyogenes under oxidative stress environments. Recognizing the factors that modulate S. pyogenes survival and virulence under stress will assist in understanding its interactions with the host.
Collapse
Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Parvati Iyer
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| |
Collapse
|
6
|
Banerji R, Saroj SD. Interspecies signaling affects virulence related morphological characteristics of Streptococcus pyogenes M3. FEMS Microbiol Lett 2021; 368:6307514. [PMID: 34156082 DOI: 10.1093/femsle/fnab079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/18/2021] [Indexed: 01/03/2023] Open
Abstract
Streptococcus pyogenes is a Gram-positive human-specific pathogen that asymptomatically colonizes the human respiratory tract. The factors affecting the colonization to the host is not clearly understood. Adherence of the pathogen to host epithelial cell is the initial step for a successful colonization process. In the host, bacteria live in a polymicrobial community; thus, the signaling mediated between the bacteria plays a significant role in the colonization of the pathogen to the host. Thus, the effect of acyl-homoserine lactone, secreted by Gram-negative bacteria on the adhesion properties of S. pyogenes M3 strain was examined. N-(3-Oxododecanoyl)-L-homoserine lactone (Oxo-C12) increased the cell size as well as hydrophobicity of S. pyogenes. qPCR data revealed that the expression of sagA and hasA was negatively affected by Oxo-C12. Moreover, Oxo-C12 leads to changes in the morphological characteristic of S. pyogenes, further promoting adherence to host epithelia and biofilm formation on abiotic surface. The study demonstrates the role of Oxo-C12 as a factor that can promote virulence in S. pyogenes M3.
Collapse
Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune 412115, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune 412115, Maharashtra, India
| |
Collapse
|
7
|
Alves-Barroco C, Paquete-Ferreira J, Santos-Silva T, Fernandes AR. Singularities of Pyogenic Streptococcal Biofilms - From Formation to Health Implication. Front Microbiol 2021; 11:584947. [PMID: 33424785 PMCID: PMC7785724 DOI: 10.3389/fmicb.2020.584947] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/20/2020] [Indexed: 01/09/2023] Open
Abstract
Biofilms are generally defined as communities of cells involved in a self-produced extracellular matrix adhered to a surface. In biofilms, the bacteria are less sensitive to host defense mechanisms and antimicrobial agents, due to multiple strategies, that involve modulation of gene expression, controlled metabolic rate, intercellular communication, composition, and 3D architecture of the extracellular matrix. These factors play a key role in streptococci pathogenesis, contributing to therapy failure and promoting persistent infections. The species of the pyogenic group together with Streptococcus pneumoniae are the major pathogens belonging the genus Streptococcus, and its biofilm growth has been investigated, but insights in the genetic origin of biofilm formation are limited. This review summarizes pyogenic streptococci biofilms with details on constitution, formation, and virulence factors associated with formation.
Collapse
Affiliation(s)
- Cinthia Alves-Barroco
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - João Paquete-Ferreira
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Teresa Santos-Silva
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Alexandra R Fernandes
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| |
Collapse
|
8
|
Nguyen VA, Ogura K, Matsue M, Takemoto N, Mukai K, Nakajima Y, Hoang TL, Iwata Y, Sakai N, Wada T, Hashimoto W, Okamoto S, Ichimura H. Novel Hyaluronate Lyase Involved in Pathogenicity of Streptococcus dysgalactiae subsp. equisimilis. Front Microbiol 2020; 11:552418. [PMID: 33072013 PMCID: PMC7541959 DOI: 10.3389/fmicb.2020.552418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/28/2020] [Indexed: 11/30/2022] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes cellulitis, bacteremia, and invasive diseases, such as streptococcal toxic shock syndrome. Although SDSE infection is more prevalent among elderly individuals and those with diabetes mellitus than infections with Streptococcus pyogenes (Group A streptococci; GAS) and Streptococcus agalactiae (Group B streptococci; GBS), the mechanisms underlying the pathogenicity of SDSE remain unknown. SDSE possesses a gene hylD encoding a hyaluronate lyase (HylD), whose homologue (HylB) is involved in pathogenicity of GBS, while the role of HylD has not been characterized. In this study, we focused on the enzyme HylD produced by SDSE; HylD cleaves hyaluronate (HA) and generates unsaturated disaccharides via a β-elimination reaction. Hyaluronate-agar plate assays revealed that SDSE promoted dramatic HA degradation. SDSE expresses both HylD and an unsaturated glucuronyl hydrolase (UGL) that catalyzes the degradation of HA-derived oligosaccharides; as such, SDSE was more effective at HA degradation than other β-hemolytic streptococci, including GAS and GBS. Although HylD shows some homology to HylB, a similar enzyme produced by GBS, HylD exhibited significantly higher enzymatic activity than HylB at pH 6.0, conditions that are detected in the skin of both elderly individuals and those with diabetes mellitus. We also detected upregulation of transcripts from hylD and ugl genes from SDSE wild-type collected from the mouse peritoneal cavity; upregulated expression of ugl was not observed in ΔhylD SDSE mutants. These results suggested that disaccharides produced by the actions of HylD are capable of triggering downstream pathways that catalyze their destruction. Furthermore, we determined that infection with SDSEΔhylD was significantly less lethal than infection with the parent strain. When mouse skin wounds were infected for 2 days, intensive infiltration of neutrophils was observed around the wound areas infected with SDSE wild-type but not SDSEΔhylD. Our investigation suggested that HylD and UGL play important roles in nutrient acquisition from hosts, followed by the bacterial pathogenicity damaging host tissues.
Collapse
Affiliation(s)
- Van An Nguyen
- Department of Viral Infection and International Health, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kohei Ogura
- Advanced Health Care Science Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Japan
| | - Miki Matsue
- Department of Clinical Laboratory Science, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Norihiko Takemoto
- Pathogenic Microbe Laboratory, Research Institute, National Center for Global Health and Medicine, Shinjuku, Japan
| | - Kanae Mukai
- Department of Nursing Sciences, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Yukari Nakajima
- Department of Nursing Sciences, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Thuy Linh Hoang
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Yasunori Iwata
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan.,Division of Infection Control, Kanazawa University, Kanazawa, Japan
| | - Norihiko Sakai
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Takashi Wada
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan.,Department of Clinical Laboratory, Kanazawa University Hospital, Kanazawa, Japan
| | - Wataru Hashimoto
- Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Shigefumi Okamoto
- Department of Clinical Laboratory Science, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Hiroshi Ichimura
- Department of Viral Infection and International Health, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| |
Collapse
|
9
|
Buckley SJ, Davies MR, McMillan DJ. In silico characterisation of stand-alone response regulators of Streptococcus pyogenes. PLoS One 2020; 15:e0240834. [PMID: 33075055 PMCID: PMC7571705 DOI: 10.1371/journal.pone.0240834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Bacterial “stand-alone” response regulators (RRs) are pivotal to the control of gene transcription in response to changing cytosolic and extracellular microenvironments during infection. The genome of group A Streptococcus (GAS) encodes more than 30 stand-alone RRs that orchestrate the expression of virulence factors involved in infecting multiple tissues, so causing an array of potentially lethal human diseases. Here, we analysed the molecular epidemiology and biological associations in the coding sequences (CDSs) and upstream intergenic regions (IGRs) of 35 stand-alone RRs from a collection of global GAS genomes. Of the 944 genomes analysed, 97% encoded 32 or more of the 35 tested RRs. The length of RR CDSs ranged from 297 to 1587 nucleotides with an average nucleotide diversity (π) of 0.012, while the IGRs ranged from 51 to 666 nucleotides with average π of 0.017. We present new evidence of recombination in multiple RRs including mga, leading to mga-2 switching, emm-switching and emm-like gene chimerization, and the first instance of an isolate that encodes both mga-1 and mga-2. Recombination was also evident in rofA/nra and msmR loci with 15 emm-types represented in multiple FCT (fibronectin-binding, collagen-binding, T-antigen)-types, including novel emm-type/FCT-type pairings. Strong associations were observed between concatenated RR allele types, and emm-type, MLST-type, core genome phylogroup, and country of sampling. No strong associations were observed between individual loci and disease outcome. We propose that 11 RRs may form part of future refinement of GAS typing systems that reflect core genome evolutionary associations. This subgenomic analysis revealed allelic traits that were informative to the biological function, GAS strain definition, and regional outbreak detection.
Collapse
Affiliation(s)
- Sean J. Buckley
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- * E-mail:
| | - Mark R. Davies
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - David J. McMillan
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| |
Collapse
|
10
|
Wu X, Zha J, Koffas MAG. Microbial production of bioactive chemicals for human health. Curr Opin Food Sci 2020. [DOI: 10.1016/j.cofs.2019.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
11
|
Creti R, Gherardi G, Imperi M. To be capsulated or not be capsulated: that is the GAS question. Eur J Clin Microbiol Infect Dis 2019; 38:2381-2383. [DOI: 10.1007/s10096-019-03677-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 11/27/2022]
|
12
|
Mohan N, Pavan SS, Achar A, Swaminathan N, Sivaprakasam S. Calorespirometric investigation of Streptococcus zooepidemicus metabolism: Thermodynamics of anabolic payload contribution by growth and hyaluronic acid synthesis. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
13
|
Adil M, Baig MH, Rupasinghe HV. Impact of Citral and Phloretin, Alone and in Combination, on Major Virulence Traits of Streptococcus pyogenes. Molecules 2019; 24:molecules24234237. [PMID: 31766432 PMCID: PMC6930587 DOI: 10.3390/molecules24234237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 11/17/2022] Open
Abstract
Streptococcus pyogenes is well documented as a multi-virulent and exclusively human pathogen. The LuxS-based signaling in these bacteria has a crucial role in causing several infections through pathways that are pathogenic. This study evaluated the individual and synergistic effects of citral and phloretin against S. pyogenes in relation to major virulence traits. The in vitro synergy of citral and phloretin was evaluated by the checkerboard method. The fractional inhibitory concentration (FIC) values were calculated to determine the interactions between the inhibitors. The bacteria’s virulence properties were tested in the presence of the molecules, individually as well as in combination. Molecules’ cytotoxicity was tested using human tonsil epithelial cells. The synergistic effects of the molecules on the expression of biofilm and quorum sensing genes were tested using quantitative real-time polymerase chain reaction (qRT-PCR). The molecules were also tested for their impact on LuxS protein by molecular docking, modeling, and free-energy calculations. When the two molecules were assessed in combination (synergistic effect, FIC Index of 0.5), a stronger growth inhibitory activity was exhibited than the individual molecules. The cell surface hydrophobicity, as well as genes involved in quorum sensing and biofilm formation, showed greater suppression when the molecules were tested in combination. The in silico findings also suggest the inhibitory potential of the two molecules against LuxS protein. The binding orientation and the binding affinity of citral and phloretin well support the notion that there is a synergistic effect of citral and phloretin. The data reveal the combination of citral and phloretin as a potent antibacterial agent to combat the virulence of S. pyogenes.
Collapse
Affiliation(s)
- Mohd Adil
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada;
| | - Mohd Hassan Baig
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 06273, Korea;
| | - H.P. Vasantha Rupasinghe
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada;
- Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, NS B3H 4H7, Canada
- Correspondence:
| |
Collapse
|
14
|
Lamb LE, Siggins MK, Scudamore C, Macdonald W, Turner CE, Lynskey NN, Tan LKK, Sriskandan S. Impact of contusion injury on intramuscular emm1 group a streptococcus infection and lymphatic spread. Virulence 2018; 9:1074-1084. [PMID: 30052105 PMCID: PMC6068544 DOI: 10.1080/21505594.2018.1482180] [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] [Indexed: 11/09/2022] Open
Abstract
Invasive group A Streptococcus (iGAS) is frequently associated with emm1 isolates, with an attendant mortality of around 20%. Cases occasionally arise in previously healthy individuals with a history of upper respiratory tract infection, soft tissue contusion, and no obvious portal of entry. Using a new murine model of contusion, we determined the impact of contusion on iGAS bacterial burden and phenotype. Calibrated mild blunt contusion did not provide a focus for initiation or seeding of GAS that was detectable following systemic GAS bacteremia, but instead enhanced GAS migration to the local draining lymph node following GAS inoculation at the same time and site of contusion. Increased migration to lymph node was associated with emergence of mucoid bacteria, although was not specific to mucoid bacteria. In one study, mucoid colonies demonstrated a significant increase in capsular hyaluronan that was not linked to a covRS or rocA mutation, but to a deletion in the promoter of the capsule synthesis locus, hasABC, resulting in a strain with increased fitness for lymph node migration. In summary, in the mild contusion model used, we could not detect seeding of muscle by GAS. Contusion promoted bacterial transit to the local lymph node. The consequences of contusion-associated bacterial lymphatic migration may vary depending on the pathogen and virulence traits selected.
Collapse
Affiliation(s)
- L E Lamb
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK.,b Royal Centre for Defence Medicine , University of Birmingham , Birmingham , UK
| | - M K Siggins
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK
| | - C Scudamore
- c Harwell Science and Innovation Campus , MRC Harwell , Oxfordshire , UK
| | - W Macdonald
- d Department of Bio-engineering , Royal School of Mines, Imperial College London , London , UK
| | - C E Turner
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK
| | - N N Lynskey
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK
| | - L K K Tan
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK
| | - S Sriskandan
- a Section of Infectious Diseases and Immunity, Department of Medicine , Imperial College London , London , UK
| |
Collapse
|
15
|
Flores AR, Luna RA, Runge JK, Shelburne SA, Baker CJ. Cluster of Fatal Group A Streptococcal emm87 Infections in a Single Family: Molecular Basis for Invasion and Transmission. J Infect Dis 2017; 215:1648-1652. [PMID: 28383686 DOI: 10.1093/infdis/jix177] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/03/2017] [Indexed: 11/15/2022] Open
Abstract
Hypervirulent disease due to group A Streptococcus (GAS) can result from strains with mutations that enhance virulence gene expression but reduce subsequent transmission. We used whole-genome sequencing to investigate intrafamilial spread among 4 siblings of infection due to a hypervirulent GAS strain that resulted in a fatality. All invasive and pharyngeal GAS isolates had an identical mutation in a gene encoding a key regulatory protein that yielded a hyperinvasive phenotype. These data challenge the prevailing theory of reduced transmission induced by mutations that lead to hypervirulent GAS by showing that spread of hypervirulent GAS may lead to clusters of invasive disease.
Collapse
Affiliation(s)
- Anthony R Flores
- Section of Infectious Diseases, Department of Pediatrics.,Department of Molecular Virology and Microbiology, Baylor College of Medicine
| | - Ruth Ann Luna
- Department of Pathology and Immunology.,Texas Children's Microbiome Center, Texas Children's Hospital
| | - Jessica K Runge
- Department of Pathology and Immunology.,Texas Children's Microbiome Center, Texas Children's Hospital
| | - Samuel A Shelburne
- Infectious Diseases.,Genomic Medicine, Division of Internal Medicine, University of Texas MD Anderson Cancer Center, Houston
| | - Carol J Baker
- Section of Infectious Diseases, Department of Pediatrics.,Department of Molecular Virology and Microbiology, Baylor College of Medicine
| |
Collapse
|
16
|
Abundance and co-occurrence of extracellular capsules increase environmental breadth: Implications for the emergence of pathogens. PLoS Pathog 2017; 13:e1006525. [PMID: 28742161 PMCID: PMC5542703 DOI: 10.1371/journal.ppat.1006525] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/03/2017] [Accepted: 07/12/2017] [Indexed: 02/06/2023] Open
Abstract
Extracellular capsules constitute the outermost layer of many bacteria, are major virulence factors, and affect antimicrobial therapies. They have been used as epidemiological markers and recently became vaccination targets. Despite the efforts to biochemically serotype capsules in a few model pathogens, little is known of their taxonomic and environmental distribution. We developed, validated, and made available a computational tool, CapsuleFinder, to identify capsules in genomes. The analysis of over 2500 prokaryotic genomes, accessible in a database, revealed that ca. 50% of them—including Archaea—encode a capsule. The Wzx/Wzy-dependent capsular group was by far the most abundant. Surprisingly, a fifth of the genomes encode more than one capsule system—often from different groups—and their non-random co-occurrence suggests the existence of negative and positive epistatic interactions. To understand the role of multiple capsules, we queried more than 6700 metagenomes for the presence of species encoding capsules and showed that their distribution varied between environmental categories and, within the human microbiome, between body locations. Species encoding capsules, and especially those encoding multiple capsules, had larger environmental breadths than the other species. Accordingly, capsules were more frequent in environmental bacteria than in pathogens and, within the latter, they were more frequent among facultative pathogens. Nevertheless, capsules were frequent in clinical samples, and were usually associated with fast-growing bacteria with high infectious doses. Our results suggest that capsules increase the environmental range of bacteria and make them more resilient to environmental perturbations. Capsules might allow opportunistic pathogens to profit from empty ecological niches or environmental perturbations, such as those resulting from antibiotic therapy, to colonize the host. Capsule-associated virulence might thus be a by-product of environmental adaptation. Understanding the role of capsules in natural environments might enlighten their function in pathogenesis. Extracellular capsules protect bacterial cells from external aggressions such as antibiotics or desiccation, but can also be targeted by vaccines. Since little was known about their frequency across Prokaryotes, we created and made freely available a computational tool, CapsuleFinder, to identify them from genomic data. Surprisingly, its use showed that many bacterial strains, especially those with the largest genomes, encode several capsules. The frequencies of the different combinations of capsule groups depended strongly on the phyla and the groups themselves, suggesting the existence of epistatic interactions between capsules. Bacteria encoding capsule systems were found in many natural environments, and were frequent in the human microbiome. In contrast to their frequent association with virulence, we found many more capsules in non-pathogens or facultative pathogens than among obligatory pathogens. We suggest that capsules increase the environmental breadth of bacteria thereby facilitating host colonization by opportunistic pathogens.
Collapse
|
17
|
Hamad GM, H. Taha T, E. Hafez E, El Sohaimy S. Physicochemical, Molecular and Functional Characteristics of Hyaluronic Acid as a Functional Food. ACTA ACUST UNITED AC 2017. [DOI: 10.3923/ajft.2017.72.85] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
18
|
Multimerization of the Virulence-Enhancing Group A Streptococcus Transcription Factor RivR Is Required for Regulatory Activity. J Bacteriol 2016; 199:JB.00452-16. [PMID: 27795318 DOI: 10.1128/jb.00452-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/17/2016] [Indexed: 12/27/2022] Open
Abstract
Group A Streptococcus (GAS) (Streptococcus pyogenes) causes more than 700 million human infections each year. The significant morbidity and mortality rates associated with GAS infections are in part a consequence of the ability of this pathogen to coordinately regulate virulence factor expression during infection. RofA-like protein IV (RivR) is a member of the Mga-like family of transcriptional regulators, and previously we reported that RivR negatively regulates transcription of the hasA and grab virulence factor-encoding genes. Here, we determined that RivR inhibits the ability of GAS to survive and to replicate in human blood. To begin to assess the biochemical basis of RivR activity, we investigated its ability to form multimers, which is a characteristic of Mga-like proteins. We found that RivR forms both dimers and a higher-molecular-mass multimer, which we hypothesize is a tetramer. As cysteine residues are known to contribute to the ability of proteins to dimerize, we created a library of expression plasmids in which each of the four cysteines in RivR was converted to serine. While the C68S RivR protein was essentially unaffected in its ability to dimerize, the C32S and C377S proteins were attenuated, while the C470S protein completely lacked the ability to dimerize. Consistent with dimerization being required for regulatory activity, the C470S RivR protein was unable to repress hasA and grab gene expression in a rivR mutant. Thus, multimer formation is a prerequisite for RivR activity, which supports recent data obtained for other Mga-like family members, suggesting a common regulatory mechanism. IMPORTANCE The modulation of gene transcription is key to the ability of bacterial pathogens to infect hosts to cause disease. Here, we discovered that the group A Streptococcus transcription factor RivR negatively regulates the ability of this pathogen to survive in human blood, and we also began biochemical characterization of this protein. We determined that, in order for RivR to function, it must self-associate, forming both dimers (consisting of two RivR proteins) and higher-order complexes (consisting of more than two RivR proteins). This functional requirement for RivR is shared by other regulators in the same family of proteins, suggesting a common regulatory mechanism. Insight into how these transcription factors function may facilitate the development of novel therapeutic agents targeting their activity.
Collapse
|
19
|
Edgar RJ, Chen J, Kant S, Rechkina E, Rush JS, Forsberg LS, Jaehrig B, Azadi P, Tchesnokova V, Sokurenko EV, Zhu H, Korotkov KV, Pancholi V, Korotkova N. SpyB, a Small Heme-Binding Protein, Affects the Composition of the Cell Wall in Streptococcus pyogenes. Front Cell Infect Microbiol 2016; 6:126. [PMID: 27790410 PMCID: PMC5061733 DOI: 10.3389/fcimb.2016.00126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 09/27/2016] [Indexed: 12/01/2022] Open
Abstract
Streptococcus pyogenes (Group A Streptococcus or GAS) is a hemolytic human pathogen associated with a wide variety of infections ranging from minor skin and throat infections to life-threatening invasive diseases. The cell wall of GAS consists of peptidoglycan sacculus decorated with a carbohydrate comprising a polyrhamnose backbone with immunodominant N-acetylglucosamine side-chains. All GAS genomes contain the spyBA operon, which encodes a 35-amino-acid membrane protein SpyB, and a membrane-bound C3-like ADP-ribosyltransferase SpyA. In this study, we addressed the function of SpyB in GAS. Phenotypic analysis of a spyB deletion mutant revealed increased bacterial aggregation, and reduced sensitivity to β-lactams of the cephalosporin class and peptidoglycan hydrolase PlyC. Glycosyl composition analysis of cell wall isolated from the spyB mutant suggested an altered carbohydrate structure compared with the wild-type strain. Furthermore, we found that SpyB associates with heme and protoporphyrin IX. Heme binding induces SpyB dimerization, which involves disulfide bond formation between the subunits. Thus, our data suggest the possibility that SpyB activity is regulated by heme.
Collapse
Affiliation(s)
- Rebecca J. Edgar
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| | - Jing Chen
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| | - Sashi Kant
- Department of Pathology, Ohio State UniversityColumbus, OH, USA
| | - Elena Rechkina
- Department of Microbiology, University of WashingtonSeattle, WA, USA
| | - Jeffrey S. Rush
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| | | | - Bernhard Jaehrig
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
| | | | | | - Haining Zhu
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| | - Konstantin V. Korotkov
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| | - Vijay Pancholi
- Department of Pathology, Ohio State UniversityColumbus, OH, USA
| | - Natalia Korotkova
- Department of Molecular and Cellular Biochemistry, University of KentuckyLexington, KY, USA
| |
Collapse
|
20
|
Viszwapriya D, Prithika U, Deebika S, Balamurugan K, Pandian SK. In vitro and in vivo antibiofilm potential of 2,4-Di- tert -butylphenol from seaweed surface associated bacterium Bacillus subtilis against group A streptococcus. Microbiol Res 2016; 191:19-31. [DOI: 10.1016/j.micres.2016.05.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/11/2016] [Accepted: 05/20/2016] [Indexed: 02/08/2023]
|
21
|
Intergenic Variable-Number Tandem-Repeat Polymorphism Upstream of rocA Alters Toxin Production and Enhances Virulence in Streptococcus pyogenes. Infect Immun 2016; 84:2086-2093. [PMID: 27141081 DOI: 10.1128/iai.00258-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/26/2016] [Indexed: 01/05/2023] Open
Abstract
Variable-number tandem-repeat (VNTR) polymorphisms are ubiquitous in bacteria. However, only a small fraction of them has been functionally studied. Here, we report an intergenic VNTR polymorphism that confers an altered level of toxin production and increased virulence in Streptococcus pyogenes The nature of the polymorphism is a one-unit deletion in a three-tandem-repeat locus upstream of the rocA gene encoding a sensor kinase. S. pyogenes strains with this type of polymorphism cause human infection and produce significantly larger amounts of the secreted cytotoxins S. pyogenes NADase (SPN) and streptolysin O (SLO). Using isogenic mutant strains, we demonstrate that deleting one or more units of the tandem repeats abolished RocA production, reduced CovR phosphorylation, derepressed multiple CovR-regulated virulence factors (such as SPN and SLO), and increased virulence in a mouse model of necrotizing fasciitis. The phenotypic effect of the VNTR polymorphism was nearly the same as that of inactivating the rocA gene. In summary, we identified and characterized an intergenic VNTR polymorphism in S. pyogenes that affects toxin production and virulence. These new findings enhance understanding of rocA biology and the function of VNTR polymorphisms in S. pyogenes.
Collapse
|
22
|
Transcriptome Remodeling Contributes to Epidemic Disease Caused by the Human Pathogen Streptococcus pyogenes. mBio 2016; 7:mBio.00403-16. [PMID: 27247229 PMCID: PMC4895104 DOI: 10.1128/mbio.00403-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects. The confluence of studies of molecular events underlying pathogen strain emergence, evolutionary genetic processes mediating altered virulence, and epidemics is in its infancy. Although understanding these events is necessary to develop new or improved strategies to protect health, surprisingly few studies have addressed this issue, in particular, at the comprehensive population genomic level. Herein we establish that substantial remodeling of the transcriptome of the human-specific pathogen Streptococcus pyogenes by horizontal gene flow and other evolutionary genetic changes is a central factor in precipitating and perpetuating epidemic disease. The data unambiguously show that the key outcome of these molecular events is evolution of a new, more virulent pathogenic genotype. Our findings provide new understanding of epidemic disease.
Collapse
|
23
|
Trading Capsule for Increased Cytotoxin Production: Contribution to Virulence of a Newly Emerged Clade of emm89 Streptococcus pyogenes. mBio 2015; 6:e01378-15. [PMID: 26443457 PMCID: PMC4611041 DOI: 10.1128/mbio.01378-15] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strains of emm89 Streptococcus pyogenes have become one of the major causes of invasive infections worldwide in the last 10 years. We recently sequenced the genome of 1,125 emm89 strains and identified three major phylogenetic groups, designated clade 1, clade 2, and the epidemic clade 3. Epidemic clade 3 strains, which now cause the great majority of infections, have two distinct genetic features compared to clade 1 and clade 2 strains. First, all clade 3 organisms have a variant 3 nga promoter region pattern, which is associated with increased production of secreted cytolytic toxins SPN (S. pyogenes NADase) and SLO (streptolysin O). Second, all clade 3 strains lack the hasABC locus mediating hyaluronic acid capsule synthesis, whereas this locus is intact in clade 1 and clade 2 strains. We constructed isogenic mutant strains that produce different levels of SPN and SLO toxins and capsule (none, low, or high). Here we report that emm89 strains with elevated toxin production are significantly more virulent than low-toxin producers. Importantly, we also show that capsule production is dispensable for virulence in strains that already produce high levels of SPN and SLO. Our results provide new understanding about the molecular mechanisms contributing to the rapid emergence and molecular pathogenesis of epidemic clade 3 emm89 S. pyogenes. S. pyogenes (group A streptococcus [GAS]) causes pharyngitis (“strep throat”), necrotizing fasciitis, and other human infections. Serious infections caused by emm89 S. pyogenes strains have recently increased in frequency in many countries. Based on whole-genome sequence analysis of 1,125 strains recovered from patients on two continents, we discovered that a new emm89 clone, termed clade 3, has two distinct genetic features compared to its predecessors: (i) absence of the genes encoding antiphagocytic hyaluronic acid capsule virulence factor and (ii) increased production of the secreted cytolytic toxins SPN and SLO. emm89 S. pyogenes strains with the clade 3 phenotype (absence of capsule and high expression of SPN and SLO) are highly virulent in mice. These findings provide new understanding of how new virulent clones emerge and cause severe infections worldwide. This newfound knowledge of S. pyogenes virulence can be used to help understand future epidemics and conduct new translational research.
Collapse
|
24
|
Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes. Sci Rep 2015; 5:10799. [PMID: 26028191 PMCID: PMC4450579 DOI: 10.1038/srep10799] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/30/2015] [Indexed: 11/08/2022] Open
Abstract
Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways.
Collapse
|
25
|
Schmid J, Sieber V, Rehm B. Bacterial exopolysaccharides: biosynthesis pathways and engineering strategies. Front Microbiol 2015; 6:496. [PMID: 26074894 PMCID: PMC4443731 DOI: 10.3389/fmicb.2015.00496] [Citation(s) in RCA: 306] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 05/06/2015] [Indexed: 12/13/2022] Open
Abstract
Bacteria produce a wide range of exopolysaccharides which are synthesized via different biosynthesis pathways. The genes responsible for synthesis are often clustered within the genome of the respective production organism. A better understanding of the fundamental processes involved in exopolysaccharide biosynthesis and the regulation of these processes is critical toward genetic, metabolic and protein-engineering approaches to produce tailor-made polymers. These designer polymers will exhibit superior material properties targeting medical and industrial applications. Exploiting the natural design space for production of a variety of biopolymer will open up a range of new applications. Here, we summarize the key aspects of microbial exopolysaccharide biosynthesis and highlight the latest engineering approaches toward the production of tailor-made variants with the potential to be used as valuable renewable and high-performance products for medical and industrial applications.
Collapse
Affiliation(s)
- Jochen Schmid
- Chair of Chemistry of Biogenic Resources, Technische Universität MünchenStraubing, Germany
| | - Volker Sieber
- Chair of Chemistry of Biogenic Resources, Technische Universität MünchenStraubing, Germany
| | - Bernd Rehm
- Institute of Fundamental Sciences, Massey UniversityPalmerston North, New Zealand
- The MacDiarmid Institute for Advanced Materials and NanotechnologyPalmerston North, New Zealand
| |
Collapse
|
26
|
HAMADA S, KAWABATA S, NAKAGAWA I. Molecular and genomic characterization of pathogenic traits of group A Streptococcus pyogenes. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2015; 91:539-59. [PMID: 26666305 PMCID: PMC4773581 DOI: 10.2183/pjab.91.539] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Group A streptococcus (GAS) or Streptococcus pyogenes causes various diseases ranging from self-limiting sore throat to deadly invasive diseases. The genome size of GAS is 1.85-1.9 Mb, and genomic rearrangement has been demonstrated. GAS possesses various surface-associated substances such as hyaluronic capsule, M proteins, and fibronectin/laminin/immunoglobulin-binding proteins. These are related to the virulence and play multifaceted and mutually reflected roles in the pathogenesis of GAS infections. Invasion of GAS into epithelial cells and deeper tissues provokes immune and non-immune defense or inflammatory responses including the recruitment of neutrophils, macrophages, and dendritic cells in hosts. GAS frequently evades host defense mechanisms by using its virulence factors. Extracellular products of GAS may perturb cellular and subcellular functions and degrade tissues enzymatically, which leads to the aggravation of local and/or systemic disorders in the host. In this review, we summarize some important cellular and extracellular substances that may affect pathogenic processes during GAS infections, and the host responses to these.
Collapse
Affiliation(s)
- Shigeyuki HAMADA
- Research Institute for Microbial Diseases, Japan-Thailand Collaboration Center for Emerging and Reemerging Infections, Osaka University, Osaka, Japan
- Correspondence should be addressed: S. Hamada, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan (e-mail: )
| | - Shigetada KAWABATA
- Department of Oral and Molecular Microbiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Ichiro NAKAGAWA
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| |
Collapse
|