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Odo CM, Vega LA, Mukherjee P, DebRoy S, Flores AR, Shelburne SA. Emergent emm4 group A Streptococcus evidences a survival strategy during interaction with immune effector cells. Infect Immun 2024; 92:e0015224. [PMID: 38888310 PMCID: PMC11238559 DOI: 10.1128/iai.00152-24] [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: 04/08/2024] [Accepted: 05/23/2024] [Indexed: 06/20/2024] Open
Abstract
The major gram-positive pathogen group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it causes waves of infections. Since 1980, several GAS epidemics have been ascribed to the emergence of clones producing increased amounts of key virulence factors such as streptolysin O (SLO). Herein, we sought to identify mechanisms underlying our recently identified temporal clonal emergence among emm4 GAS, given that emergent strains did not produce augmented levels of virulence factors relative to historic isolates. By creating and analyzing isoallelic strains, we determined that a conserved mutation in a previously undescribed gene encoding a putative carbonic anhydrase was responsible for the defective in vitro growth observed in the emergent strains. We also identified that the emergent strains survived better inside macrophages and killed macrophages at lower rates than the historic strains. Via the creation of isogenic mutant strains, we linked the emergent strain "survival" phenotype to the downregulation of the SLO encoding gene and upregulation of the msrAB operon which encodes proteins involved in defense against extracellular oxidative stress. Our findings are in accord with recent surveillance studies which found a high ratio of mucosal (i.e., pharyngeal) relative to invasive infections among emm4 GAS. Since ever-increasing virulence is unlikely to be evolutionarily advantageous for a microbial pathogen, our data further understanding of the well-described oscillating patterns of virulent GAS infections by demonstrating mechanisms by which emergent strains adapt a "survival" strategy to outcompete previously circulating isolates.
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Affiliation(s)
- Chioma M. Odo
- Microbiology and Infectious Disease, MD Anderson UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Luis A. Vega
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Piyali Mukherjee
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Sruti DebRoy
- Department of Infectious Disease, MD Anderson Cancer Center, Houston, Texas, USA
| | - Anthony R. Flores
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Sciences Center Houston, Houston, Texas, USA
| | - Samuel A. Shelburne
- Department of Infectious Disease, MD Anderson Cancer Center, Houston, Texas, USA
- Department of Genomic Medicine, MD Anderson Cancer Center, Houston, Texas, USA
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Rampersadh K, Salie MT, Engel KC, Moodley C, Zühlke LJ, Engel ME. Presence of Group A streptococcus frequently assayed virulence genes in invasive disease: a systematic review and meta-analysis. Front Cell Infect Microbiol 2024; 14:1337861. [PMID: 39055978 PMCID: PMC11270091 DOI: 10.3389/fcimb.2024.1337861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/18/2024] [Indexed: 07/28/2024] Open
Abstract
Introduction It is currently unclear what the role of Group A streptococcus (GAS) virulence factors (VFs) is in contributing to the invasive potential of GAS. This work investigated the evidence for the association of GAS VFs with invasive disease. Methods We employed a broad search strategy for studies reporting the presence of GAS VFs in invasive and non-invasive GAS disease. Data were independently extracted by two reviewers, quality assessed, and meta-analyzed using Stata®. Results A total of 32 studies reported on 45 putative virulence factors [invasive (n = 3,236); non-invasive (n = 5,218)], characterized by polymerase chain reaction (PCR) (n = 30) and whole-genome sequencing (WGS) (n = 2). The risk of bias was rated as low and moderate, in 23 and 9 studies, respectively. Meta-,analyses of high-quality studies (n = 23) revealed a significant association of speM [OR, 1.64 (95%CI, 1.06; 2.52)] with invasive infection. Meta-analysis of WGS studies demonstrated a significant association of hasA [OR, 1.91 (95%CI, 1.36; 2.67)] and speG [OR, 2.83 (95%CI, 1.63; 4.92)] with invasive GAS (iGAS). Meta-analysis of PCR studies indicated a significant association of speA [OR, 1.59 (95%CI, 1.10; 2.30)] and speK [OR, 2.95 (95%CI, 1.81; 4.80)] with invasive infection. A significant inverse association was observed between prtf1 [OR, 0.42 (95%CI, 0.20; 0.87)] and invasive infection. Conclusion This systematic review and genomic meta-analysis provides evidence of a statistically significant association with invasive infection for the hasA gene, while smeZ, ssa, pnga3, sda1, sic, and NaDase show statistically significantly inverse associations with invasive infection. SpeA, speK, and speG are associated with GAS virulence; however, it is unclear if they are markers of invasive infection. This work could possibly aid in developing preventative strategies.
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Affiliation(s)
- Kimona Rampersadh
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - M. Taariq Salie
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - Kelin C. Engel
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - Clinton Moodley
- Department of Pathology, Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- The National Health Laboratory Service, Microbiology, Groote Schuur Hospital, Cape Town, South Africa
| | - Liesl J. Zühlke
- Division of Paediatric Cardiology, Department of Paediatrics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- South African Medical Research Council, Parrow Valley, Cape Town, South Africa
| | - Mark E. Engel
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
- South African Medical Research Council, Parrow Valley, Cape Town, South Africa
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Odo CM, Vega LA, Mukherjee P, DebRoy S, Flores AR, Shelburne SA. Emergent emm4 group A Streptococcus evidences a survival strategy during interaction with immune effector cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.09.588776. [PMID: 38645060 PMCID: PMC11030381 DOI: 10.1101/2024.04.09.588776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The major gram-positive pathogen group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it causes waves of infections. Since 1980, several GAS epidemics have been ascribed to the emergence of clones producing increased amounts of key virulence factors such as streptolysin O (SLO). Herein, we sought to identify mechanisms underlying our recently identified temporal clonal emergence amongst emm4 GAS, given that emergent strains did not produce augmented levels of virulence factors relative to historic isolates. Through the creation and analysis of isoallelic strains, we determined that a conserved mutation in a previously undescribed gene encoding a putative carbonic anhydrase was responsible for the defective in vitro growth observed in the emergent strains. We also identified that the emergent strains survived better inside macrophages and killed macrophages at lower rates relative to the historic strains. Via creation of isogenic mutant strains, we linked the emergent strain "survival" phenotype to the downregulation of the SLO encoding gene and upregulation of the msrAB operon which encodes proteins involved in defense against extracellular oxidative stress. Our findings are in accord with recent surveillance studies which found high ratio of mucosal (i.e., pharyngeal) relative to invasive infections amongst emm4 GAS. Inasmuch as ever-increasing virulence is unlikely to be evolutionary advantageous for a microbial pathogen, our data furthers understanding of the well described oscillating patterns of virulent GAS infections by demonstrating mechanisms by which emergent strains adapt a "survival" strategy to outcompete previously circulating isolates.
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4
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Raynes JM, Young PG, Lorenz N, Loh JM, McGregor R, Baker EN, Proft T, Moreland NJ. Identification of an immunodominant region on a group A Streptococcus T-antigen reveals temperature-dependent motion in pili. Virulence 2023; 14:2180228. [PMID: 36809931 PMCID: PMC9980535 DOI: 10.1080/21505594.2023.2180228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Group A Streptococcus (GAS) is a globally important pathogen causing a broad range of human diseases. GAS pili are elongated proteins with a backbone comprised repeating T-antigen subunits, which extend from the cell surface and have important roles in adhesion and establishing infection. No GAS vaccines are currently available, but T-antigen-based candidates are in pre-clinical development. This study investigated antibody-T-antigen interactions to gain molecular insight into functional antibody responses to GAS pili. Large, chimeric mouse/human Fab-phage libraries generated from mice vaccinated with the complete T18.1 pilus were screened against recombinant T18.1, a representative two-domain T-antigen. Of the two Fab identified for further characterization, one (designated E3) was cross-reactive and also recognized T3.2 and T13, while the other (H3) was type-specific reacting with only T18.1/T18.2 within a T-antigen panel representative of the major GAS T-types. The epitopes for the two Fab, determined by x-ray crystallography and peptide tiling, overlapped and mapped to the N-terminal region of the T18.1 N-domain. This region is predicted to be buried in the polymerized pilus by the C-domain of the next T-antigen subunit. However, flow cytometry and opsonophagocytic assays showed that these epitopes were accessible in the polymerized pilus at 37°C, though not at lower temperature. This suggests that there is motion within the pilus at physiological temperature, with structural analysis of a covalently linked T18.1 dimer indicating "knee-joint" like bending occurs between T-antigen subunits to expose this immunodominant region. This temperature dependent, mechanistic flexing provides new insight into how antibodies interact with T-antigens during infection.
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Affiliation(s)
- Jeremy M. Raynes
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Paul G. Young
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,School of Biological Sciences, The University of Auckland, Auckland, New Zealand,CONTACT Paul G. Young
| | - Natalie Lorenz
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Jacelyn M.S. Loh
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Reuben McGregor
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Edward N. Baker
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Thomas Proft
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Nicole J. Moreland
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand,Nicole J. Moreland
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The Place of Group A Streptococci in Moroccan Children with Pharyngitis and Emm Type Distribution. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2021. [DOI: 10.5812/pedinfect.111172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Streptococcus pyogenes is responsible for a wide variety of diseases, including noninvasive and severe invasive infections. The emm gene encodes the M protein that is the virulence factor and immunological determinant of group A streptococci. Emm typing is the group A Streptococci (GAS) standard molecular typing method based on the amplification of the N terminal hypervariable region of the emm gene. Objectives: The aim of the present study was to determine the prevalence of GAS in children with pharyngitis and determine different types of emm gene in the GAS isolates using emm typing. Methods: The study was carried out over a period of 14 months (from February 2017 to March 2018). Throat samples were collected from cases aged ≤ 18 years with pharyngitis referring to a primary health care center in Fez, Morocco. GAS isolates were subjected to conventional tests to confirm species identification. Antimicrobial susceptibility testing was performed using the standard disk diffusion method. We researched emm gene by a polymerase chain reaction (PCR). Emm types were determined by a sequence-based protocol. Demographic and clinical data were recorded from each patient. Results: From a total of 177 throat samples, 11 isolates (6.2%) were identified as GAS in children with pharyngitis. Antibiotic sensitivity testing revealed that all the GAS isolates were sensitive to penicillin. The sequencing of the PCR products of the emm gene revealed that emm90 was the most obtained emm type (30,77%); while emm75 was the least type observed (7.7%). Conclusions: The emm90 is the most prevalent type detected from patients with tonsillitis. Penicillin and erythromycin are still the foremost effective antibiotics to treat GAS pharyngitis.
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Vogel V, Spellerberg B. Bacteriocin Production by Beta-Hemolytic Streptococci. Pathogens 2021; 10:pathogens10070867. [PMID: 34358017 PMCID: PMC8308785 DOI: 10.3390/pathogens10070867] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 01/17/2023] Open
Abstract
Beta-hemolytic streptococci cause a variety of infectious diseases associated with high morbidity and mortality. A key factor for successful infection is host colonization, which can be difficult in a multispecies environment. Secreting bacteriocins can be beneficial during this process. Bacteriocins are small, ribosomally produced, antimicrobial peptides produced by bacteria to inhibit the growth of other, typically closely related, bacteria. In this systematic review, bacteriocin production and regulation of beta-hemolytic streptococci was surveyed. While Streptococcus pyogenes produces eight different bacteriocins (Streptococcin A-FF22/A-M49, Streptin, Salivaricin A, SpbMN, Blp1, Blp2, Streptococcin A-M57), only one bacteriocin of Streptococcus agalactiae (Agalacticin = Nisin P) and one of Streptococcus dysgalactiae subsp. equisimilis (Dysgalacticin) has been described. Expression of class I bacteriocins is regulated by a two-component system, typically with autoinduction by the bacteriocin itself. In contrast, a separate quorum sensing system regulates expression of class II bacteriocins. Both identified class III bacteriocins are plasmid-encoded and regulation has not been elucidated.
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Rafei R, Hawli M, Osman M, Khelissa S, Salloum T, Dabboussi F, Tokajian S, Hamze M. Molecular epidemiology of nonpharyngeal group A streptococci isolates in northern Lebanon. Future Microbiol 2020; 15:1555-1569. [PMID: 33236928 DOI: 10.2217/fmb-2020-0072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aim: To characterize the epidemiology of group A Streptococcus (GAS) involved in nonpharyngeal infections sparingly addressed in Lebanon. Materials & methods: A collection of 63 nonpharyngeal GAS isolates recovered between 2010 and 2019 from northern Lebanon were analyzed through emm typing, virulence gene profiling, FCT typing and antibiotic susceptibility analysis. Results & conclusion: A total of 29 emm subtypes was detected, with emm1 being the most dominant. A great intraclonal divergence driven by the loss and gain of superantigens or by the structural variability within the FCT regions was unraveled. The resistance rates for erythromycin and tetracycline were 8 and 20.6%, respectively. The 30-valent vaccine coverage was 76%. This study evidences the complexity of the neglected GAS pathogen in Lebanon.
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Affiliation(s)
- Rayane Rafei
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School for Science & Technology, Faculty of Public Health, Lebanese University, Tripoli, 1300, Lebanon
| | - Malaik Hawli
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School for Science & Technology, Faculty of Public Health, Lebanese University, Tripoli, 1300, Lebanon
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School for Science & Technology, Faculty of Public Health, Lebanese University, Tripoli, 1300, Lebanon
| | - Simon Khelissa
- Université de Lille, Centre National de la Recherche Scientifique, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Centrale Lille, Unité Mixte de Recherche 8207 - Unité Matériaux et Transformations, Lille, 59000, France
| | - Tamara Salloum
- Department of Natural Sciences, School of Arts & Sciences, Lebanese American University, Byblos campus, Postal Box 36, Byblos, 1401, Lebanon
| | - Fouad Dabboussi
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School for Science & Technology, Faculty of Public Health, Lebanese University, Tripoli, 1300, Lebanon
| | - Sima Tokajian
- Department of Natural Sciences, School of Arts & Sciences, Lebanese American University, Byblos campus, Postal Box 36, Byblos, 1401, Lebanon
| | - Monzer Hamze
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School for Science & Technology, Faculty of Public Health, Lebanese University, Tripoli, 1300, Lebanon
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Giffard PM, Tong SYC, Holt DC, Ralph AP, Currie BJ. Concerns for efficacy of a 30-valent M-protein-based Streptococcus pyogenes vaccine in regions with high rates of rheumatic heart disease. PLoS Negl Trop Dis 2019; 13:e0007511. [PMID: 31269021 PMCID: PMC6634427 DOI: 10.1371/journal.pntd.0007511] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 07/16/2019] [Accepted: 06/03/2019] [Indexed: 11/21/2022] Open
Abstract
The prevalence of rheumatic heart disease (RHD) in the Aboriginal population of the Australian Northern Territory is high, and Streptococcus pyogenes skin infections likely contribute to this. A promising candidate S. pyogenes “30mer” vaccine is composed of 30 pharyngitis associated type-specific antigens from the S. pyogenes M protein. Cross opsonisation experiments suggest that 30mer vaccine protection may extend to non-cognate emm types. A new “emm cluster” scheme for classifying M protein is based on the full-length coding sequence, and correlates with functional and immunological properties, and anatomical tropism. Twenty-seven years of research in the Northern Territory has yielded 1810 S. pyogenes isolates with clinical and emm type data. The primary aim was to analyse these data with reference to the emm cluster scheme and cross opsonisation information, to inform estimation of 30mer vaccine efficacy in the Northern Territory. The isolates encompass 101 emm types. Variants of cluster A-C were enriched in throat isolates, and variants of emm cluster D enriched in skin isolates. Throat isolates were enriched for 30mer vaccine cognate emm types in comparison with skin isolates of which only 25% were vaccine emm types. While cross opsonisation data indicates potential for enhancing 30mer vaccine coverage, more than one third of skin isolates were within 38 emm types untested for cross opsonisation. Emm cluster D variants, in particular emm cluster D4, were not only all non-cognate with the vaccine, but were abundant and diverse, and less likely to be cross-opsonisation positive than other emm clusters. Long term persistence of many emm types in the study area was revealed. It was concluded that the 30mer vaccine efficacy in the Northern Territory will likely require both cross protection, and additional measures to elicit immunity against variants of emm cluster D. The bacterium Streptococcus pyogenes causes throat and skin infections. A danger from such infections is an immune response that attacks human heart tissue, leading to rheumatic heart disease, which is difficult to treat and potentially deadly. Disadvantaged populations such as the Indigenous people in remote tropical northern Australia have high burdens of S. pyogenes skin infection, and rheumatic heart disease. An effective vaccine would be a benefit, but none is approved for clinical use. We analysed data from 1810 S. pyogenes isolates from north Australia obtained over 28 years, to determine the potential of a previously described S. pyogenes vaccine candidate to be effective in this region. Only one quarter of the isolates from skin infections had a surface antigen corresponding to any one of the 30 antigen variants in the candidate vaccine. Previous work in animals indicates potential cross-protection from the vaccine against strains with mismatched antigens. However, even if this occurs in humans, protection against skin infection strains would likely remain compromised, unless there were additional components in the vaccine. Further studies on cross-protection are critical to defining the potential of this type of vaccine in populations burdened with S. pyogenes skin infections and rheumatic heart disease.
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Affiliation(s)
- Philip M. Giffard
- Menzies School of Health Research, Division of Global and Tropical Health, Darwin, Australia
- College of Health and Human Sciences, Charles Darwin University, Darwin, Australia
- * E-mail:
| | - Steven Y. C. Tong
- Menzies School of Health Research, Division of Global and Tropical Health, Darwin, Australia
- Victorian Infectious Disease Service, The Royal Melbourne Hospital, and Doherty Department University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Deborah C. Holt
- Menzies School of Health Research, Division of Global and Tropical Health, Darwin, Australia
- College of Health and Human Sciences, Charles Darwin University, Darwin, Australia
| | - Anna P. Ralph
- Menzies School of Health Research, Division of Global and Tropical Health, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Australia
| | - Bart J. Currie
- Menzies School of Health Research, Division of Global and Tropical Health, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Australia
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Hertzog BB, Kaufman Y, Biswas D, Ravins M, Ambalavanan P, Wiener R, Angeli V, Chen SL, Hanski E. A Sub-population of Group A Streptococcus Elicits a Population-wide Production of Bacteriocins to Establish Dominance in the Host. Cell Host Microbe 2018; 23:312-323.e6. [PMID: 29544095 DOI: 10.1016/j.chom.2018.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/26/2017] [Accepted: 02/07/2018] [Indexed: 11/30/2022]
Abstract
Bacteria use quorum sensing (QS) to regulate gene expression. We identified a group A Streptococcus (GAS) strain possessing the QS system sil, which produces functional bacteriocins, through a sequential signaling pathway integrating host and bacterial signals. Host cells infected by GAS release asparagine (ASN), which is sensed by the bacteria to alter its gene expression and rate of proliferation. We show that upon ASN sensing, GAS upregulates expression of the QS autoinducer peptide SilCR. Initial SilCR expression activates the autoinduction cycle for further SilCR production. The autoinduction process propagates throughout the GAS population, resulting in bacteriocin production. Subcutaneous co-injection of mice with a bacteriocin-producing strain and the globally disseminated M1T1 GAS clone results in M1T1 killing within soft tissue. Thus, by sensing host signals, a fraction of a bacterial population can trigger an autoinduction mechanism mediated by QS, which acts on the entire bacterial community to outcompete other bacteria within the infection.
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Affiliation(s)
- Baruch B Hertzog
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research, Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Yael Kaufman
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research, Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Debabrata Biswas
- NUS-HUJ-CREATE Programme for Inflammation Research, Center for Research Excellence & Technological Enterprise (CREATE), Department of Microbiology and Immunology, National University of Singapore, Singapore 138602, Singapore
| | - Miriam Ravins
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research, Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Poornima Ambalavanan
- NUS-HUJ-CREATE Programme for Inflammation Research, Center for Research Excellence & Technological Enterprise (CREATE), Department of Microbiology and Immunology, National University of Singapore, Singapore 138602, Singapore
| | - Reuven Wiener
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research, Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem 9112102, Israel
| | - Veronique Angeli
- Department of Microbiology and Immunology, National University of Singapore; LSI Immunology Programme, National University of Singapore, Singapore 117456, Singapore
| | - Swaine L Chen
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, and Infectious Diseases Group, Genome Institute of Singapore, Singapore 119074, Singapore
| | - Emanuel Hanski
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research, Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem 9112102, Israel; NUS-HUJ-CREATE Programme for Inflammation Research, Center for Research Excellence & Technological Enterprise (CREATE), Department of Microbiology and Immunology, National University of Singapore, Singapore 138602, Singapore.
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Buckley SJ, Timms P, Davies MR, McMillan DJ. In silico characterisation of the two-component system regulators of Streptococcus pyogenes. PLoS One 2018; 13:e0199163. [PMID: 29927994 PMCID: PMC6013163 DOI: 10.1371/journal.pone.0199163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/02/2018] [Indexed: 12/14/2022] Open
Abstract
Bacteria respond to environmental changes through the co-ordinated regulation of gene expression, often mediated by two-component regulatory systems (TCS). Group A Streptococcus (GAS), a bacterium which infects multiple human body sites and causes multiple diseases, possesses up to 14 TCS. In this study we examined genetic variation in the coding sequences and non-coding DNA upstream of these TCS as a method for evaluating relationships between different GAS emm-types, and potential associations with GAS disease. Twelve of the 14 TCS were present in 90% of the genomes examined. The length of the intergenic regions (IGRs) upstream of TCS coding regions varied from 39 to 345 nucleotides, with an average nucleotide diversity of 0.0064. Overall, IGR allelic variation was generally conserved with an emm-type. Subsequent phylogenetic analysis of concatenated sequences based on all TCS IGR sequences grouped genomes of the same emm-type together. However grouping with emm-pattern and emm-cluster-types was much weaker, suggesting epidemiological and functional properties associated with the latter are not due to evolutionary relatedness of emm-types. All emm5, emm6 and most of the emm18 genomes, all historically considered rheumatogenic emm-types clustered together, suggesting a shared evolutionary history. However emm1, emm3 and several emm18 genomes did not cluster within this group. These latter emm18 isolates were epidemiologically distinct from other emm18 genomes in study, providing evidence for local variation. emm-types associated with invasive disease or nephritogenicity also did not cluster together. Considering the TCS coding sequences (cds), correlation with emm-type was weaker than for the IGRs, and no strong correlation with disease was observed. Deletion of the malate transporter, maeP, was identified that serves as a putative marker for the emm89.0 subtype, which has been implicated in invasive outbreaks. A recombination-related, subclade-forming DNA motif was identified in the putative receiver domain of the Spy1556 response regulator that correlated with throat-associated emm-pattern-type A-C strains.
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Affiliation(s)
- Sean J. Buckley
- Inflammation and Healing Biomedical Research Cluster, and School of Health and Sports Sciences, Faculty of Science, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Peter Timms
- Inflammation and Healing Biomedical Research Cluster, and School of Health and Sports Sciences, Faculty of Science, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Mark R. Davies
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - David J. McMillan
- Inflammation and Healing Biomedical Research Cluster, and School of Health and Sports Sciences, Faculty of Science, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
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Chen M, Wang W, Tu L, Zheng Y, Pan H, Wang G, Chen Y, Zhang X, Zhu L, Chen J, Chen M. An emm5 Group A Streptococcal Outbreak Among Workers in a Factory Manufacturing Telephone Accessories. Front Microbiol 2017; 8:1156. [PMID: 28680421 PMCID: PMC5478724 DOI: 10.3389/fmicb.2017.01156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/07/2017] [Indexed: 01/06/2023] Open
Abstract
Ranked among the top10 infectious causes of death worldwide, group A Streptococcus (GAS) causes small- and large-scale outbreaks, depending on the trigger as transmission of a GAS strain or expansion of predominant clones. In China, GAS infections other than scarlet fever are not notifiable. In Shanghai, an epidemiological investigation was initiated after two successive severe pneumonia cases with one death in a digital factory, from where outbreaks are less widely reported. The investigation was performed using emm typing, pulsed-field gel electrophoresis (PFGE) typing, superantigen profiling, and genome analysis. This enabled characterization of relatedness among the outbreak isolates and identification of the mobile genetic elements present. Among 57 patients with respiratory symptoms investigated in the factory, emm5 GAS strains were isolated from 8 patients. The eight GAS infection cases comprising one fatal severe pneumonia case, six influenza-like illness cases, and one pharyngitis case. Two risk factors were identified: adult with an age of 18–20 years and close contact with a GAS patient or carrier. GAS attack rate was 14.0% (8/57), and GAS carriage rate was probably around 2.7% (14/521) based on surveys in two nearby districts. All the 10 outbreak associated isolates were assigned to emm5 and sequence type ST-99 (emm5/ST-99), harbored superantigen genes speC, speG, and smeZ, and were assigned to two similar PFGE patterns (clones). Among the outbreak associated isolates, all carried ermA with resistance to erythromycin and inducible resistance to clindamycin, and eight (80%) carried a tetM gene with resistance to tetracycline. Among the 14 carriage isolates, 12 were emm12/ST-36, and 2 were emm1/ST-28, all with superantigen genes speC, speG, ssa, and smeZ. All the carriage isolates harbored ermB and tetM with resistance to erythromycin, clindamycin, and tetracycline. Genome analysis showed the two outbreak clones were closely related and possessed new prophages carrying virulence gene sdc and antibiotic resistance genes of ermA and tetM, which were not found in the emm5 reference strain Manfredo. This is the first report of a GAS outbreak in this type of workplace. The outbreak was caused by two closely related emm5 clones that differed from the predominant emm types circulating in China.
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Affiliation(s)
- Mingliang Chen
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China.,Shanghai Institutes of Preventive MedicineShanghai, China
| | - Wenqing Wang
- Pudong New Area Center for Disease Control and PreventionShanghai, China
| | - Lihong Tu
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Yaxu Zheng
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Hao Pan
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Gangyi Wang
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Yanxin Chen
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Xi Zhang
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Linying Zhu
- Pudong New Area Center for Disease Control and PreventionShanghai, China
| | - Jian Chen
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
| | - Min Chen
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China
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12
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Identification of a two-component Class IIb bacteriocin in Streptococcus pyogenes by recombinase-based in vivo expression technology. Sci Rep 2016; 6:36233. [PMID: 27808235 PMCID: PMC5093712 DOI: 10.1038/srep36233] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 10/10/2016] [Indexed: 12/30/2022] Open
Abstract
Streptococcus pyogenes is a globally prominent bacterial pathogen that exhibits strict tropism for the human host, yet bacterial factors responsible for the ability of S. pyogenes to compete within this limited biological niche are not well understood. Using an engineered recombinase-based in vivo expression technology (RIVET) system, we identified an in vivo-induced promoter region upstream of a predicted Class IIb bacteriocin system in the M18 serotype S. pyogenes strain MGAS8232. This promoter element was not active under in vitro laboratory conditions, but was highly induced within the mouse nasopharynx. Recombinant expression of the predicted mature S. pyogenes bacteriocin peptides (designated SpbM and SpbN) revealed that both peptides were required for antimicrobial activity. Using a gain of function experiment in Lactococcus lactis, we further demonstrated S. pyogenes immunity function is encoded downstream of spbN. These data highlight the importance of bacterial gene regulation within appropriate environments to help understand mechanisms of niche adaptation by bacterial pathogens.
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13
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Bessen DE, McShan WM, Nguyen SV, Shetty A, Agrawal S, Tettelin H. Molecular epidemiology and genomics of group A Streptococcus. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2015; 33:393-418. [PMID: 25460818 PMCID: PMC4416080 DOI: 10.1016/j.meegid.2014.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/11/2014] [Accepted: 10/13/2014] [Indexed: 12/15/2022]
Abstract
Streptococcus pyogenes (group A Streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed.
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Affiliation(s)
- Debra E Bessen
- Department of Microbiology & Immunology, New York Medical College, Valhalla, NY 10595, USA.
| | - W Michael McShan
- University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences, College of Pharmacy, Oklahoma City, OK 73117, USA.
| | - Scott V Nguyen
- University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences, College of Pharmacy, Oklahoma City, OK 73117, USA.
| | - Amol Shetty
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Sonia Agrawal
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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