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Root-Bernstein R. T-Cell Receptor Sequences Identify Combined Coxsackievirus- Streptococci Infections as Triggers for Autoimmune Myocarditis and Coxsackievirus- Clostridia Infections for Type 1 Diabetes. Int J Mol Sci 2024; 25:1797. [PMID: 38339075 PMCID: PMC10855694 DOI: 10.3390/ijms25031797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/19/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Recent research suggests that T-cell receptor (TCR) sequences expanded during human immunodeficiency virus and SARS-CoV-2 infections unexpectedly mimic these viruses. The hypothesis tested here is that TCR sequences expanded in patients with type 1 diabetes mellitus (T1DM) and autoimmune myocarditis (AM) mimic the infectious triggers of these diseases. Indeed, TCR sequences mimicking coxsackieviruses, which are implicated as triggers of both diseases, are statistically significantly increased in both T1DM and AM patients. However, TCRs mimicking Clostridia antigens are significantly expanded in T1DM, whereas TCRs mimicking Streptococcal antigens are expanded in AM. Notably, Clostridia antigens mimic T1DM autoantigens, such as insulin and glutamic acid decarboxylase, whereas Streptococcal antigens mimic cardiac autoantigens, such as myosin and laminins. Thus, T1DM may be triggered by combined infections of coxsackieviruses with Clostridia bacteria, while AM may be triggered by coxsackieviruses with Streptococci. These TCR results are consistent with both epidemiological and clinical data and recent experimental studies of cross-reactivities of coxsackievirus, Clostridial, and Streptococcal antibodies with T1DM and AM antigens. These data provide the basis for developing novel animal models of AM and T1DM and may provide a generalizable method for revealing the etiologies of other autoimmune diseases. Theories to explain these results are explored.
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Lacey JA, Bennett J, James TB, Hines BS, Chen T, Lee D, Sika-Paotonu D, Anderson A, Harwood M, Tong SY, Baker MG, Williamson DA, Moreland NJ. A worldwide population of Streptococcus pyogenes strains circulating among school-aged children in Auckland, New Zealand: a genomic epidemiology analysis. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2024; 42:100964. [PMID: 38035130 PMCID: PMC10684382 DOI: 10.1016/j.lanwpc.2023.100964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/20/2023] [Accepted: 10/29/2023] [Indexed: 12/02/2023]
Abstract
Background Acute rheumatic fever (ARF) is a serious post-infectious sequala of Group A Streptococcus (GAS, Streptococcus pyogenes). In New Zealand (NZ) ARF is a major cause of health inequity. This study describes the genomic analysis of GAS isolates associated with childhood skin and throat infections in Auckland NZ. Methods Isolates (n = 469) collected between March 2018 and October 2019 from the throats and skin of children (5-14 years) underwent whole genomic sequencing. Equal representation across three ethnic groups was ensured through sample quotas with isolates obtained from Indigenous Māori (n = 157, 33%), NZ European/Other (n = 149, 32%) and Pacific Peoples children (n = 163, 35%). Using in silico techniques isolates were classified, assessed for diversity, and examined for distribution differences between groups. Comparisons were also made with GAS strains identified globally. Findings Genomic analysis revealed a diverse population consisting of 65 distinct sequence clusters. These sequence clusters spanned 49 emm-types, with 11 emm-types comprised of several, distinct sequence clusters. There is evidence of multiple global introductions of different lineages into the population, as well as local clonal expansion. The M1UK lineage comprised 35% of all emm1 isolates. Interpretation The GAS population was characterized by a high diversity of strains, resembling patterns observed in low- and middle-income countries. However, strains associated with outbreaks and antimicrobial resistance commonly found in high-income countries were also observed. This unique combination poses challenges for vaccine development, disease management and control. Funding The work was supported by the Health Research Council of New Zealand (HRC), award number 16/005.
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Affiliation(s)
- Jake A. Lacey
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Julie Bennett
- The Department of Public Health, University of Otago, Wellington, New Zealand
- The Maurice Wilkins Centre for Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Taylah B. James
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Benjamin S. Hines
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Victoria, Australia
| | - Tiffany Chen
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Darren Lee
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Anneka Anderson
- Te Kupenga Hauora Māori, The University of Auckland, New Zealand
| | - Matire Harwood
- Department of General Practice and Primary Healthcare, The University of Auckland, Auckland, New Zealand
| | - Steven Y.C. Tong
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Department of Infectious Diseases at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Michael G. Baker
- The Department of Public Health, University of Otago, Wellington, New Zealand
- The Maurice Wilkins Centre for Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Deborah A. Williamson
- Department of Infectious Diseases at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Nicole J. Moreland
- The Maurice Wilkins Centre for Biodiscovery, The University of Auckland, Auckland, New Zealand
- Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
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Egoroff N, Bloomfield H, Gondarra W, Yambalpal B, Guyula T, Forward D, Lyons G, O'Connor E, Sanderson L, Dowden M, Williams D, de Dassel J, Coffey P, Dhurrkay ER, Gondarra V, Holt DC, Krause VL, Currie BJ, Griffiths K, Dempsey K, Glynn-Robinson A. An outbreak of acute rheumatic fever in a remote Aboriginal community. Aust N Z J Public Health 2023; 47:100077. [PMID: 37625204 DOI: 10.1016/j.anzjph.2023.100077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/08/2023] [Accepted: 07/12/2023] [Indexed: 08/27/2023] Open
Abstract
OBJECTIVES We describe the public health response to an outbreak of acute rheumatic fever (ARF) in a remote Aboriginal community. METHODS In August 2021, the Northern Territory Rheumatic Heart Disease Control Program identified an outbreak of acute rheumatic fever in a remote Aboriginal community. A public health response was developed using a modified acute poststreptococcal glomerulonephritis protocol and the National Acute Rheumatic Fever Guideline for Public Health Units. RESULTS 12 cases were diagnosed during the outbreak; six-times the average number of cases in the same period in the five years prior (n=1.8). Half (n=6) of the outbreak cases were classified as recurrent episodes with overdue secondary prophylaxis. Contact tracing and screening of 11 households identified 86 close contacts. CONCLUSIONS This outbreak represented an increase in both first episodes and recurrences of acute rheumatic fever and highlights the critical need for strengthened delivery of acute rheumatic fever secondary prophylaxis, and for improvements to the social determinants of health in the region. IMPLICATIONS FOR PUBLIC HEALTH Outbreaks of acute rheumatic fever are rare despite continuing high rates of acute rheumatic fever experienced by remote Aboriginal communities. Nevertheless, there can be improvements in the current national public health guidance relating to acute rheumatic fever cluster and outbreak management.
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Affiliation(s)
- Natasha Egoroff
- National Centre for Epidemiology and Population Health, Australian National University, Australia; Miwatj Health Aboriginal Corporation, Australia; Centre for Disease Control, Northern Territory Health, Australia.
| | - Hilary Bloomfield
- Miwatj Health Aboriginal Corporation, Australia; Centre for Disease Control, Northern Territory Health, Australia.
| | | | | | - Terrence Guyula
- Centre for Disease Control, Northern Territory Health, Australia.
| | - Demi Forward
- Miwatj Health Aboriginal Corporation, Australia.
| | - Gemma Lyons
- Miwatj Health Aboriginal Corporation, Australia.
| | - Emer O'Connor
- Miwatj Health Aboriginal Corporation, Australia; Centre for Disease Control, Northern Territory Health, Australia; Rheumatic Heart Disease Australia, Australia.
| | | | | | - Desley Williams
- Centre for Disease Control, Northern Territory Health, Australia.
| | | | | | | | | | - Deborah C Holt
- Menzies School of Health Research, Charles Darwin University, Australia.
| | - Vicki L Krause
- Centre for Disease Control, Northern Territory Health, Australia.
| | - Bart J Currie
- Menzies School of Health Research, Charles Darwin University, Australia; Rheumatic Heart Disease Australia, Australia.
| | - Kalinda Griffiths
- Menzies School of Health Research, Charles Darwin University, Australia; University of New South Wales, Australia; University of Melbourne, Australia.
| | | | - Anna Glynn-Robinson
- National Centre for Epidemiology and Population Health, Australian National University, Australia.
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Dale JB, Aranha MP, Penfound TA, Salehi S, Smith JC. Structure-guided design of a broadly cross-reactive multivalent group a streptococcal vaccine. Vaccine 2023; 41:5841-5847. [PMID: 37596198 PMCID: PMC10529471 DOI: 10.1016/j.vaccine.2023.08.026] [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: 04/25/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/20/2023]
Abstract
The M protein of group A streptococci (Strep A) is a major virulence determinant and protective antigen. The N-terminal region of the M protein is variable in sequence, defines the M/emm type, and contains epitopes that elicit opsonic antibodies that protect animals from challenge infections. Although there are >200 M types of Strep A, there is now evidence that structurally related M proteins can be grouped into clusters and that immunity may be cluster-specific in addition to M type-specific. This observation has led to recent studies of structure-based design of multivalent M peptide vaccines to select peptides predicted to cross-react with heterologous M types to improve vaccine coverage. In the current study, we have applied a refined series of peptide structural algorithms to predict immunological cross-reactivity among 117 N-terminal M peptides representing the most prevalent M types of Strep A. Based on the results of the structural analyses, in combination with global M type prevalence data, we constructed a 32-valent vaccine containing 19 cross-reactive vaccine candidates predicted to cross-react with 37 heterologous M peptides to which were added 13 type-specific M peptides. The 4-protein recombinant vaccine was immunogenic in rabbits and elicited significant levels of antibodies against 31/32 (97%) vaccine peptides and 28/37 (76%) peptides predicted to cross-react. The vaccine antisera also promoted opsonophagocytic killing of vaccine and cross-reactive M types of Strep A. Based on a recent analysis of M type prevalence of Strep A, the potential global coverage of the 32-valent vaccine is ∼90%, ranging from 68% in Africa to 95% in North America. Our results indicate the utility of structure-based design that may be applied to future studies of broadly protective M peptide vaccines.
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Affiliation(s)
- James B Dale
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN 38163, United States; Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, United States.
| | - Michelle P Aranha
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States
| | - Thomas A Penfound
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Sanaz Salehi
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Jeremy C Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States
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5
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Lacey JA, Marcato AJ, Chisholm RH, Campbell PT, Zachreson C, Price DJ, James TB, Morris JM, Gorrie CL, McDonald MI, Bowen AC, Giffard PM, Holt DC, Currie BJ, Carapetis JR, Andrews RM, Davies MR, Geard N, McVernon J, Tong SYC. Evaluating the role of asymptomatic throat carriage of Streptococcus pyogenes in impetigo transmission in remote Aboriginal communities in Northern Territory, Australia: a retrospective genomic analysis. THE LANCET. MICROBE 2023; 4:e524-e533. [PMID: 37211022 DOI: 10.1016/s2666-5247(23)00068-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 05/23/2023]
Abstract
BACKGROUND Streptococcus pyogenes, or group A Streptococcus (GAS), infections contribute to a high burden of disease in Aboriginal Australians, causing skin infections and immune sequelae such as rheumatic heart disease. Controlling skin infections in these populations has proven difficult, with transmission dynamics being poorly understood. We aimed to identify the relative contributions of impetigo and asymptomatic throat carriage to GAS transmission. METHODS In this genomic analysis, we retrospectively applied whole genome sequencing to GAS isolates that were collected as part of an impetigo surveillance longitudinal household survey conducted in three remote Aboriginal communities in the Northern Territory of Australia between Aug 6, 2003, and June 22, 2005. We included GAS isolates from all throats and impetigo lesions of people living in two of the previously studied communities. We classified isolates into genomic lineages based on pairwise shared core genomes of more than 99% with five or fewer single nucleotide polymorphisms. We used a household network analysis of epidemiologically and genomically linked lineages to quantify the transmission of GAS within and between households. FINDINGS We included 320 GAS isolates in our analysis: 203 (63%) from asymptomatic throat swabs and 117 (37%) from impetigo lesions. Among 64 genomic lineages (encompassing 39 emm types) we identified 264 transmission links (involving 93% of isolates), for which the probable source was asymptomatic throat carriage in 166 (63%) and impetigo lesions in 98 (37%). Links originating from impetigo cases were more frequent between households than within households. Households were infected with GAS for a mean of 57 days (SD 39 days), and once cleared, reinfected 62 days (SD 40 days) later. Increased household size and community presence of GAS and scabies were associated with slower clearance of GAS. INTERPRETATION In communities with high prevalence of endemic GAS-associated skin infection, asymptomatic throat carriage is a GAS reservoir. Public health interventions such as vaccination or community infection control programmes aimed at interrupting transmission of GAS might need to include consideration of asymptomatic throat carriage. FUNDING Australian National Health and Medical Research Council.
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Affiliation(s)
- Jake A Lacey
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC Australia
| | - Adrian J Marcato
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC Australia
| | - Rebecca H Chisholm
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC Australia; Department of Mathematical and Physical Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Patricia T Campbell
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC Australia
| | - Cameron Zachreson
- School of Computing and Information systems, Faculty of Engineering and Information Technology, University of Melbourne, Melbourne, VIC Australia
| | - David J Price
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC Australia
| | - Taylah B James
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC Australia
| | - Jacqueline M Morris
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC Australia
| | - Claire L Gorrie
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC Australia
| | - Malcolm I McDonald
- Division of Tropical Health and Medicine, James Cook University, Nguma-bada Campus, Cairns, QLD, Australia
| | - Asha C Bowen
- Telethon Kids Institute, University of Western Australia and Perth Children's Hospital, Perth, WA, Australia
| | - Philip M Giffard
- Global and Tropical Healthy Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; School of Medicine, Faculty of Health, Charles Darwin University, Darwin, NT, Australia
| | - Deborah C Holt
- Global and Tropical Healthy Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; School of Medicine, Faculty of Health, Charles Darwin University, Darwin, NT, Australia
| | - Bart J Currie
- Global and Tropical Healthy Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Jonathan R Carapetis
- Telethon Kids Institute, University of Western Australia and Perth Children's Hospital, Perth, WA, Australia
| | - Ross M Andrews
- Global and Tropical Healthy Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC Australia
| | - Nicholas Geard
- School of Computing and Information systems, Faculty of Engineering and Information Technology, University of Melbourne, Melbourne, VIC Australia
| | - Jodie McVernon
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Victorian Infectious Diseases Reference Laboratory Epidemiology Unit, University of Melbourne, Melbourne, VIC Australia
| | - Steven Y C Tong
- Department of Infectious Diseases, University of Melbourne, Melbourne, VIC Australia; Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Melbourne, at the Peter Doherty Institute for Infection and Immunity VIC, Australia; Global and Tropical Healthy Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
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6
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Brouwer S, Rivera-Hernandez T, Curren BF, Harbison-Price N, De Oliveira DMP, Jespersen MG, Davies MR, Walker MJ. Pathogenesis, epidemiology and control of Group A Streptococcus infection. Nat Rev Microbiol 2023; 21:431-447. [PMID: 36894668 PMCID: PMC9998027 DOI: 10.1038/s41579-023-00865-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2023] [Indexed: 03/11/2023]
Abstract
Streptococcus pyogenes (Group A Streptococcus; GAS) is exquisitely adapted to the human host, resulting in asymptomatic infection, pharyngitis, pyoderma, scarlet fever or invasive diseases, with potential for triggering post-infection immune sequelae. GAS deploys a range of virulence determinants to allow colonization, dissemination within the host and transmission, disrupting both innate and adaptive immune responses to infection. Fluctuating global GAS epidemiology is characterized by the emergence of new GAS clones, often associated with the acquisition of new virulence or antimicrobial determinants that are better adapted to the infection niche or averting host immunity. The recent identification of clinical GAS isolates with reduced penicillin sensitivity and increasing macrolide resistance threatens both frontline and penicillin-adjunctive antibiotic treatment. The World Health Organization (WHO) has developed a GAS research and technology road map and has outlined preferred vaccine characteristics, stimulating renewed interest in the development of safe and effective GAS vaccines.
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Affiliation(s)
- Stephan Brouwer
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | | | - Bodie F Curren
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Nichaela Harbison-Price
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - David M P De Oliveira
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Magnus G Jespersen
- Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.
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Muacevic A, Adler JR, Toor D, Lyngdoh V, Nongrum G, Kapoor M, Chakraborti A. Group A Streptococcus Infections: Their Mechanisms, Epidemiology, and Current Scope of Vaccines. Cureus 2022; 14:e33146. [PMID: 36721580 PMCID: PMC9884514 DOI: 10.7759/cureus.33146] [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] [Accepted: 11/13/2022] [Indexed: 01/01/2023] Open
Abstract
Group A streptococci (GAS) are gram-positive, cocci-shaped bacteria that cause a wide variety of infections and are a cause of significant health burden, particularly in lower- and middle-income nations. The GAS genome contains a number of virulence factors such as the M-protein, hyaluronic acid, C5a peptidase, etc. Despite its significant health burden across the globe, a proper vaccine against GAS infections is not yet available. Various candidates for an effective GAS vaccine are currently being researched. These are based on various parts of the streptococcal genome. These include candidates based on the N-terminal region of the M protein, the conserved C-terminal region of the M protein, and other parts of the streptococcal genome. The development of a vaccine against GAS infections is hampered by certain challenges, such as extensive genetic heterogeneity and high protein sequence variation. This review paper sheds light on the various virulence factors of GAS, their epidemiology, the different vaccine candidates currently being researched, and the challenges associated with M-protein and non-M-protein-based vaccines. This review also sheds light on the current scenario regarding the status of vaccine development against GAS-related infections.
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Norpi ASM, Nordin ML, Ahmad N, Katas H, Fuaad AAHA, Sukri A, Marasini N, Azmi F. New modular platform based on multi-adjuvanted amphiphilic chitosan nanoparticles for efficient lipopeptide vaccine delivery against group A streptococcus. Asian J Pharm Sci 2022; 17:435-446. [PMID: 35782331 PMCID: PMC9237632 DOI: 10.1016/j.ajps.2022.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 11/02/2022] Open
Abstract
An effective vaccine against group A streptococcus (GAS) is highly desirable for definitive control of GAS infections. In the present study, two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were developed. The vaccines were primarily composed of encapsulated KLH protein (a source of T helper cell epitopes) and lipidated M-protein derived B cell peptide epitope (lipoJ14) within the amphiphilic structure of nanoparticles. The only difference between them was one of the nanoparticles vaccines received additional surface coating with poly (I:C). The formulated vaccines exhibited nanosized particles within the range of 220–240 nm. Cellular uptake study showed that nanoparticles vaccine without additional poly (I:C) coating has greater uptake by dendritic cells and macrophages compared to nanoparticles vaccine that was functionalized with poly (I:C). Both vaccines were found to be safe in mice and showed negligible cytotoxicity against HEK293 cells. Upon immunization in mice, both nanoparticle vaccines produced high antigen-specific antibodies titres that were regulated by a balanced Th1 and Th2 response compared to physical mixture. These antibodies elicited high opsonic activity against the tested GAS strains. Overall, our data demonstrated that amphiphilic chitosan nanoparticles platform induced a potent immune response even without additional inclusion of poly (I:C).
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Rafei R, Al Iaali R, Osman M, Dabboussi F, Hamze M. A global snapshot on the prevalent macrolide-resistant emm types of Group A Streptococcus worldwide, their phenotypes and their resistance marker genotypes during the last two decades: A systematic review. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 99:105258. [PMID: 35219865 DOI: 10.1016/j.meegid.2022.105258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 12/29/2021] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
Watchful epidemiological surveillance of macrolide-resistant Group A Streptococcus (MRGAS) clones is important owing to the evolutionary and epidemiological dynamic of GAS. Meanwhile, data on the global distribution of MRGAS emm types according to macrolide resistance phenotypes and genotypes are scant and need to be updated. For this, the present systematic review analyses a global set of extensively characterized MRGAS isolates from patients of diverse ages and clinical presentations over approximately two decades (2000 to 2020) and recaps the peculiar epidemiological features of the dominant MRGAS clones. Based on the inclusion and exclusion criteria, 53 articles (3593 macrolide-resistant and 15,951 susceptible isolates) distributed over 23 countries were dissected with a predominance of high-income countries over low-income ones. Although macrolide resistance in GAS is highly variable in different countries, its within-GAS distribution seems not to be random. emm pattern E, 13 major emm types (emm12, 4, 28, 77, 75, 11, 22, 92, 58, 60, 94, 63, 114) and 4 emm clusters (A-C4, E1, E6, and E2) were significantly associated with macrolide resistance. emm patterns A-C and D, 14 major emm types (emm89, 3, 6, 2, 44, 82, 87, 118, 5, 49, 81, 59, 227, 78) and 3 well-defined emm clusters (A-C5, E3, and D4) were significantly associated with macrolide susceptibility. Scrutinizing the tendency of each MRGAS emm type to be significantly associated with specific macrolide resistance phenotype or genotype, interesting vignettes are also unveiled. The 30-valent vaccine covers ~95% of MRGAS isolates. The presented data urge the importance of comprehensive nationwide sustained surveillance of MRGAS circulating clones particularly in Low and Middle income countries where sampling bias is high and GAS epidemiology is obfuscated and needs to be demystified.
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Affiliation(s)
- Rayane Rafei
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon.
| | - Rayane Al Iaali
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon; Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
| | - Fouad Dabboussi
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
| | - Monzer Hamze
- Laboratoire Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
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Mahmoud A, Toth I, Stephenson R. Developing an Effective Glycan‐Based Vaccine for
Streptococcus Pyogenes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Asmaa Mahmoud
- School of Chemistry and Molecular Biosciences The University of Queensland St Lucia Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences The University of Queensland Woolloongabba Australia
- School of Pharmacy The Universitry of Queensland St Lucia Australia
- Institue for Molecular Biosciences The University of Queensland St Lucia Australia
| | - Rachel Stephenson
- School of Chemistry and Molecular Biosciences The University of Queensland St Lucia Australia
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11
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Mahmoud A, Toth I, Stephenson R. Developing an Effective Glycan-based Vaccine for Streptococcus Pyogenes. Angew Chem Int Ed Engl 2021; 61:e202115342. [PMID: 34935243 DOI: 10.1002/anie.202115342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Indexed: 11/11/2022]
Abstract
Streptococcus pyogenes is a primary infective agent that causes approximately 700 million human infections each year, resulting in more than 500,000 deaths. Carbohydrate-based vaccines are proven to be one of the most promising subunit vaccine candidates, as the bacterial glycan pattern(s) are different from mammalian cells and show increased pathogen serotype conservancy than the protein components. In this review we highlight reverse vaccinology for use in the development of subunit vaccines against S. pyogenes, and report reproducible methods of carbohydrate antigen production, in addition to the structure-immunogenicity correlation between group A carbohydrate epitopes and alternative vaccine antigen carrier systems. We also report recent advances used to overcome hurdles in carbohydrate-based vaccine development.
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Affiliation(s)
- Asmaa Mahmoud
- The University of Queensland - Saint Lucia Campus: The University of Queensland, School of Chemistry and Molecular Biosciences, AUSTRALIA
| | - Istvan Toth
- The University of Queensland - Saint Lucia Campus: The University of Queensland, School of Chemistry and Molecular Biosciences, AUSTRALIA
| | - Rachel Stephenson
- The University of Queensland, School of Chemistry and Molecular Biosciences, The University of Queensland, 4068, Brisbane, AUSTRALIA
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12
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Whitcombe AL, Han F, McAlister SM, Kirkham LAS, Young PG, Ritchie SR, Atatoa Carr P, Proft T, Moreland NJ. An eight-plex immunoassay for Group A streptococcus serology and vaccine development. J Immunol Methods 2021; 500:113194. [PMID: 34801540 DOI: 10.1016/j.jim.2021.113194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/11/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
Group A Streptococcus (GAS) is a major human pathogen responsible for superficial infections through to life-threatening invasive disease and the autoimmune sequelae acute rheumatic fever (ARF). Despite a significant global economic and health burden, there is no licensed vaccine available to prevent GAS disease. Several pre-clinical vaccines that target conserved GAS antigens are in development. Assays that measure antigen-specific antibodies are essential for vaccine research. The aim of this study was to develop a multiplex beadbased immunoassay that can detect and quantify antibody responses to multiple GAS antigen targets in small volume blood samples. This builds on our existing triplex assay comprised of antigens used in clinical serology for the diagnosis of ARF (SLO, DNase B and SpnA). Five additional conserved putative GAS vaccine antigens (Spy0843, SCPA, SpyCEP, SpyAD and the Group A carbohydrate), were coupled to spectrally unique beads to form an 8-plex antigen panel. After optimisation of the assay protocol, standard curves were generated, and assessments of assay specificity, precision and reproducibility were conducted. A broad range of antibody (IgG) titres were able to be quickly and accurately quantified from a single serum dilution. Assay utility was assessed using a panel of 62 clinical samples including serum from adults with GAS bacteraemia and children with ARF. Circulating IgG to all eight antigens was elevated in patients with GAS disease (n = 23) compared to age-matched controls (n = 39) (P < 0.05). The feasibility of using dried blood samples to quantify antigen-specific IgG was also demonstrated. In summary, a robust and reproducible 8-plex assay has been developed that simultaneously quantifies IgG antibodies to GAS vaccine and diagnostic antigens.
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Affiliation(s)
- Alana L Whitcombe
- School of Medical Sciences, The University of Auckland, New Zealand; Maurice Wilkins Centre for Biodiscovery, The University of Auckland, New Zealand
| | - Franklin Han
- School of Medical Sciences, The University of Auckland, New Zealand
| | - Sonia M McAlister
- Wesfarmers Centre of Vaccines & Infectious Disease, Telethon Kids Institute, Perth, Western Australia, Australia; Division of Paediatrics, School of Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Lea-Ann S Kirkham
- Wesfarmers Centre of Vaccines & Infectious Disease, Telethon Kids Institute, Perth, Western Australia, Australia; Centre for Child Health Research, University of Western Australia, Perth, Australia
| | - Paul G Young
- School of Biological Sciences, The University of Auckland, New Zealand
| | | | | | - Thomas Proft
- School of Medical Sciences, The University of Auckland, New Zealand; Maurice Wilkins Centre for Biodiscovery, The University of Auckland, New Zealand
| | - Nicole J Moreland
- School of Medical Sciences, The University of Auckland, New Zealand; Maurice Wilkins Centre for Biodiscovery, The University of Auckland, New Zealand.
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13
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Gemechu T, Parry EHO, Yacoub MH, Phillips DIW, Kotit S. Community-based prevalence of rheumatic heart disease in rural Ethiopia: Five-year follow-up. PLoS Negl Trop Dis 2021; 15:e0009830. [PMID: 34644305 PMCID: PMC8513824 DOI: 10.1371/journal.pntd.0009830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND As little is known about the prevalence and clinical progression of subclinical (latent) rheumatic heart disease (RHD) in sub-Saharan Africa, we report the results of a 5 year follow-up of a community based, echocardiographic study of the disease, originally carried out in a rural area around Jimma, Ethiopia. METHODS Individuals with evidence of RHD detected during the baseline study as well as controls and their family members were screened with a short questionnaire together with transthoracic echocardiography. RESULTS Of 56 individuals with RHD (37 definite and 19 borderline) in the original study, 36 (26 definite and 10 borderline) were successfully located 57.3 (range 44.9-70.7) months later. At follow-up two thirds of the definite cases still had definite disease; while a third had regressed. Approximately equal numbers of the borderline cases had progressed and regressed. Features of RHD had appeared in 5 of the 60 controls. There was an increased risk of RHD in the family relatives of borderline and definite cases (3.8 and 4.0 times respectively), notably among siblings. Compliance with penicillin prophylaxis was very poor. CONCLUSIONS We show the persistence of echocardiographically demonstrable RHD in a rural sub-Saharan population. Both progression and regression of the disease were found; however, the majority of the individuals who had definite features of RHD had evidence of continuing RHD lesions five years later. There was an increased risk of RHD in the family relatives of borderline and definite cases, notably among siblings. The findings highlight the problems faced in addressing the problem of RHD in the rural areas of sub-Saharan Africa. They add to the evidence that community-based interventions for RHD will be required, together with appropriate ways of identifying active disease, achieving adequate penicillin prophylaxis and developing vaccines for primary prevention.
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Affiliation(s)
| | | | - Magdi H. Yacoub
- Aswan Heart Centre, Aswan, Egypt
- NHLI, Heart Science Centre, Imperial College London, London, United Kingdom
| | - David I. W. Phillips
- Developmental Origins of Health and Disease Division, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Susy Kotit
- Aswan Heart Centre, Aswan, Egypt
- * E-mail:
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14
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Zaman M, Huber VC, Heiden DL, DeHaan KN, Chandra S, Erickson D, Ozberk V, Pandey M, Bailly B, Martin G, Langshaw EL, Zaid A, von Itzstein M, Good MF. Combinatorial liposomal peptide vaccine induces IgA and confers protection against influenza virus and bacterial super-infection. Clin Transl Immunology 2021; 10:e1337. [PMID: 34527244 PMCID: PMC8432089 DOI: 10.1002/cti2.1337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 12/18/2022] Open
Abstract
Objectives The upper respiratory tract is the major entry site for Streptococcus pyogenes and influenza virus. Vaccine strategies that activate mucosal immunity could significantly reduce morbidity and mortality because of these pathogens. The severity of influenza is significantly greater if a streptococcal infection occurs during the viraemic period and generally viral infections complicated by a subsequent bacterial infection are known as super-infections. We describe an innovative vaccine strategy against influenza virus:S. pyogenes super-infection. Moreover, we provide the first description of a liposomal multi-pathogen-based platform that enables the incorporation of both viral and bacterial antigens into a vaccine and constitutes a transformative development. Methods Specifically, we have explored a vaccination strategy with biocompatible liposomes that express conserved streptococcal and influenza A virus B-cell epitopes on their surface and contain encapsulated diphtheria toxoid as a source of T-cell help. The vaccine is adjuvanted by inclusion of the synthetic analogue of monophosphoryl lipid A, 3D-PHAD. Results We observe that this vaccine construct induces an Immunoglobulin A (IgA) response in both mice and ferrets. Vaccination reduces viral load in ferrets from influenza challenge and protects mice from both pathogens. Notably, vaccination significantly reduces both mortality and morbidity associated with a super-infection. Conclusion The vaccine design is modular and could be adapted to include B-cell epitopes from other mucosal pathogens where an IgA response is required for protection.
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Affiliation(s)
- Mehfuz Zaman
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Victor C Huber
- Division of Basic Biomedical SciencesSanford School of MedicineUniversity of South DakotaVermillionSDUSA
| | - Dustin L Heiden
- Division of Basic Biomedical SciencesSanford School of MedicineUniversity of South DakotaVermillionSDUSA
| | - Katerina N DeHaan
- Division of Basic Biomedical SciencesSanford School of MedicineUniversity of South DakotaVermillionSDUSA
| | - Sanyogita Chandra
- Division of Basic Biomedical SciencesSanford School of MedicineUniversity of South DakotaVermillionSDUSA
| | - Demi Erickson
- Division of Basic Biomedical SciencesSanford School of MedicineUniversity of South DakotaVermillionSDUSA
| | - Victoria Ozberk
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Manisha Pandey
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Benjamin Bailly
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Gael Martin
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Emma L Langshaw
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
| | - Ali Zaid
- The Emerging Viruses, Inflammation and Therapeutics GroupMenzies Health Institute QueenslandGriffith UniversityGold CoastQLDAustralia
- School of Medical SciencesGriffith UniversityGold CoastQLDAustralia
- Global Virus Network (GVN) Centre of Excellence in ArbovirusesGriffith UniversityGold CoastQLDAustralia
| | | | - Michael F Good
- Institute for GlycomicsGriffith UniversityGold CoastQLDAustralia
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15
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Aranha MP, Penfound TA, Salehi S, Botteaux A, Smeesters P, Dale JB, Smith JC. Design of Broadly Cross-Reactive M Protein-Based Group A Streptococcal Vaccines. THE JOURNAL OF IMMUNOLOGY 2021; 207:1138-1149. [PMID: 34341168 DOI: 10.4049/jimmunol.2100286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/13/2021] [Indexed: 11/19/2022]
Abstract
Group A streptococcal infections are a significant cause of global morbidity and mortality. A leading vaccine candidate is the surface M protein, a major virulence determinant and protective Ag. One obstacle to the development of M protein-based vaccines is the >200 different M types defined by the N-terminal sequences that contain protective epitopes. Despite sequence variability, M proteins share coiled-coil structural motifs that bind host proteins required for virulence. In this study, we exploit this potential Achilles heel of conserved structure to predict cross-reactive M peptides that could serve as broadly protective vaccine Ags. Combining sequences with structural predictions, six heterologous M peptides in a sequence-related cluster were predicted to elicit cross-reactive Abs with the remaining five nonvaccine M types in the cluster. The six-valent vaccine elicited Abs in rabbits that reacted with all 11 M peptides in the cluster and functional opsonic Abs against vaccine and nonvaccine M types in the cluster. We next immunized mice with four sequence-unrelated M peptides predicted to contain different coiled-coil propensities and tested the antisera for cross-reactivity against 41 heterologous M peptides. Based on these results, we developed an improved algorithm to select cross-reactive peptide pairs using additional parameters of coiled-coil length and propensity. The revised algorithm accurately predicted cross-reactive Ab binding, improving the Matthews correlation coefficient from 0.42 to 0.74. These results form the basis for selecting the minimum number of N-terminal M peptides to include in potentially broadly efficacious multivalent vaccines that could impact the overall global burden of group A streptococcal diseases.
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Affiliation(s)
- Michelle P Aranha
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN; .,Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN
| | - Thomas A Penfound
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN
| | - Sanaz Salehi
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN
| | - Anne Botteaux
- Molecular Bacteriology Laboratory, Free University of Brussels, Brussels, Belgium
| | - Pierre Smeesters
- Molecular Bacteriology Laboratory, Free University of Brussels, Brussels, Belgium.,Academic Children's Hospital Queen Fabiola, Free University of Brussels, Brussels, Belgium; and.,Centre for International Child Health, University of Melbourne, Melbourne, Victoria, Australia
| | - James B Dale
- Department of Medicine, Division of Infectious Diseases, University of Tennessee Health Science Center, Memphis, TN;
| | - Jeremy C Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN; .,Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN
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16
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Marijon E, Mocumbi A, Narayanan K, Jouven X, Celermajer DS. Persisting burden and challenges of rheumatic heart disease. Eur Heart J 2021; 42:3338-3348. [PMID: 34263296 DOI: 10.1093/eurheartj/ehab407] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/02/2021] [Accepted: 06/13/2021] [Indexed: 11/13/2022] Open
Abstract
Rheumatic heart disease (RHD) is the result of episodes of acute rheumatic fever with valvular (and other cardiac) damage caused by an abnormal immune response to group A streptococcal infections, usually during childhood and adolescence. As a result of improved living conditions and the introduction of penicillin, RHD was almost eradicated in the developed world by the 1980s. However, being a disease of poverty, its burden remains disproportionately high in the developing world, despite being a fundamentally preventable disease. Rheumatic heart disease generates relatively little attention from the medical and science communities, in contrast to other common infectious problems (such as malaria, HIV, tuberculosis), despite the major cardiovascular morbidity/mortality burden imposed by RHD. This relative neglect and paucity of funding have probably contributed to limited fundamental medical advances in this field for over 50 years. Given the importance of prevention before the onset of major valvular damage, the main challenges for RHD prevention are improving social circumstances, early diagnosis, and effective delivery of antibiotic prophylaxis. Early identification through ultrasound of silent, subclinical rheumatic valve lesions could provide an opportunity for early intervention. Simple echocardiographic diagnostic criteria and appropriately trained personnel can be valuable aids in large-scale public health efforts. In addition, a better understanding of the immunogenic determinants of the disease may provide potential routes to vaccine development and other novel therapies.
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Affiliation(s)
- Eloi Marijon
- University of Paris, PARCC, INSERM, Global Health Unit, Paris F-75015, France.,Cardiology Department, European Georges Pompidou Hospital, Paris, France
| | - Ana Mocumbi
- Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique.,Instituto Nacional de Saúde, Marracuene, Mozambique
| | - Kumar Narayanan
- University of Paris, PARCC, INSERM, Global Health Unit, Paris F-75015, France.,Medicover Hospitals, Hyderabad, India
| | - Xavier Jouven
- University of Paris, PARCC, INSERM, Global Health Unit, Paris F-75015, France.,Cardiology Department, European Georges Pompidou Hospital, Paris, France
| | - David S Celermajer
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia.,Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia
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17
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Kotit S, Phillips DIW, Afifi A, Yacoub M. The "Cairo Accord"- Towards the Eradication of RHD: An Update. Front Cardiovasc Med 2021; 8:690227. [PMID: 34277735 PMCID: PMC8282907 DOI: 10.3389/fcvm.2021.690227] [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: 04/02/2021] [Accepted: 06/07/2021] [Indexed: 01/18/2023] Open
Abstract
Rheumatic heart disease (RHD) is the most common cause of acquired heart disease in children and young adults. It continues to be prevalent in many low- and middle-income countries where it causes significant morbidity and mortality. Following the 2017 Cairo conference "Rheumatic Heart Disease: from Molecules to the Global Community," experts from 21 countries formulated an approach for addressing the problem of RHD: "The Cairo Accord on Rheumatic Heart Disease." The Accord attempts to set policy priorities for the eradication of acute rheumatic fever (ARF) and RHD and builds on a recent series of policy initiatives and calls to action. We present an update on the recommendations of the Cairo Accord and discuss recent progress toward the eradication of RHD, including contributions from our own Aswan Rheumatic Heart Disease Registry (ARGI).
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Affiliation(s)
| | - David I. W. Phillips
- Developmental Origins of Health and Disease Division, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | | | - Magdi Yacoub
- Aswan Heart Centre, Aswan, Egypt
- Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, United Kingdom
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18
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Abstract
PURPOSE OF REVIEW There is a global need for well tolerated, effective, and affordable vaccines to prevent group A streptococcal infections and their most serious complications. The aim of this review is to highlight the recent progress in the identification of promising vaccine antigens and new approaches to vaccine design that address the complexities of group A streptococcal pathogenesis and epidemiology. RECENT FINDINGS Combination vaccines containing multiple shared, cross-protective antigens have proven efficacious in mouse and nonhuman primate models of infection. The development of complex multivalent M protein-based vaccines is continuing and several have progressed through early-stage human clinical trials. Formulations of vaccines containing universal T-cell epitopes, toll-like receptor agonists, and other adjuvants more potent than alum have been shown to enhance protective immunogenicity. Although the group A streptococcal vaccine antigen landscape is populated with a number of potential candidates, the clinical development of vaccines has been impeded by a number of factors. There are now concerted global efforts to raise awareness about the need for group A streptococcal vaccines and to support progress toward eventual commercialization and licensure. SUMMARY Preclinical antigen discovery, vaccine formulation, and efficacy studies in animal models have progressed significantly in recent years. There is now a need to move promising candidates through the clinical development pathway to establish their efficacy in preventing group A streptococcal infections and their complications.
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19
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Castro SA, Dorfmueller HC. A brief review on Group A Streptococcus pathogenesis and vaccine development. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201991. [PMID: 33959354 PMCID: PMC8074923 DOI: 10.1098/rsos.201991] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is a Gram-positive human-exclusive pathogen, responsible for more than 500 000 deaths annually worldwide. Upon infection, GAS commonly triggers mild symptoms such as pharyngitis, pyoderma and fever. However, recurrent infections or prolonged exposure to GAS might lead to life-threatening conditions. Necrotizing fasciitis, streptococcal toxic shock syndrome and post-immune mediated diseases, such as poststreptococcal glomerulonephritis, acute rheumatic fever and rheumatic heart disease, contribute to very high mortality rates in non-industrialized countries. Though an initial reduction in GAS infections was observed in high-income countries, global outbreaks of GAS, causing rheumatic fever and acute poststreptococcal glomerulonephritis, have been reported over the last decade. At the same time, our understanding of GAS pathogenesis and transmission has vastly increased, with detailed insight into the various stages of infection, beginning with adhesion, colonization and evasion of the host immune system. Despite deeper knowledge of the impact of GAS on the human body, the development of a successful vaccine for prophylaxis of GAS remains outstanding. In this review, we discuss the challenges involved in identifying a universal GAS vaccine and describe several potential vaccine candidates that we believe warrant pursuit.
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Affiliation(s)
- Sowmya Ajay Castro
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Helge C. Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
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20
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Loh JMS, Rivera-Hernandez T, McGregor R, Khemlani AHJ, Tay ML, Cork AJ, M Raynes J, Moreland NJ, Walker MJ, Proft T. A multivalent T-antigen-based vaccine for Group A Streptococcus. Sci Rep 2021; 11:4353. [PMID: 33623073 PMCID: PMC7902606 DOI: 10.1038/s41598-021-83673-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/19/2021] [Indexed: 11/23/2022] Open
Abstract
Pili of Group A Streptococcus (GAS) are surface-exposed structures involved in adhesion and colonisation of the host during infection. The major protein component of the GAS pilus is the T-antigen, which multimerises to form the pilus shaft. There are currently no licenced vaccines against GAS infections and the T-antigen represents an attractive target for vaccination. We have generated a multivalent vaccine called TeeVax1, a recombinant protein that consists of a fusion of six T-antigen domains. Vaccination with TeeVax1 produces opsonophagocytic antibodies in rabbits and confers protective efficacy in mice against invasive disease. Two further recombinant proteins, TeeVax2 and TeeVax3 were constructed to cover 12 additional T-antigens. Combining TeeVax1–3 produced a robust antibody response in rabbits that was cross-reactive to a full panel of 21 T-antigens, expected to provide over 95% vaccine coverage. These results demonstrate the potential for a T-antigen-based vaccine to prevent GAS infections.
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Affiliation(s)
- Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
| | - Tania Rivera-Hernandez
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia.,Cátedras CONACYT-Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Reuben McGregor
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Adrina Hema J Khemlani
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Mei Lin Tay
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Amanda J Cork
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Jeremy M Raynes
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.,Monash University, Clayton Campus, Melbourne, VIC, Australia
| | - Nicole J Moreland
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
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21
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Taiaroa G, Matalavea B, Tafuna'i M, Lacey JA, Price DJ, Isaia L, Leaupepe H, Viali S, Lee D, Gorrie CL, Williamson DA, Jack S. Scabies and impetigo in Samoa: A school-based clinical and molecular epidemiological study. LANCET REGIONAL HEALTH-WESTERN PACIFIC 2020; 6:100081. [PMID: 34327410 PMCID: PMC8315614 DOI: 10.1016/j.lanwpc.2020.100081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/24/2020] [Accepted: 12/10/2020] [Indexed: 10/29/2022]
Abstract
Background Common infections of the skin such as impetigo and scabies represent a large burden of disease globally, being particularly prevalent in tropical and resource-limited settings. Efforts to address these infections through mass drug administrations have recently been shown as efficacious and safe. In Samoa, a Pacific Island nation, there is a marked lack of epidemiological data for these neglected tropical diseases, or appreciation of their drivers in this setting. Methods An observational, cross-sectional survey of children aged between 4 and 15 years attending primary schools in rural areas of Upolu Island, Samoa was carried out to assess the prevalence of impetigo and scabies in schoolchildren residing in rural Samoa, integrated with descriptive epidemiological and microbial genomic data. A phylogenetic assessment of local Staphylococcus aureus isolated from Samoan schoolchildren was performed to estimate putative community transmission. Findings In this survey, the prevalence of impetigo observed in Samoan schoolchildren was one of the highest described globally (57•1%, 95% CI [53•8-60•5%], 476/833). Associations between active impetigo and age and gender were noted, with younger children and males more commonly affected (aOR2•8 [1•8-4•7]and aOR1•8 [1•3-2•5], respectively). The prevalence of scabies was similar to that seen in other South Pacific island countries (14•4%, 95% CI [12•2-17•0%], 120/833). Transmission of S. aureus was predicted, primarily between those children attending the same school. Carriage of S. pyogenes was notably low, with pharyngeal carriage observed in less than 2% of schoolchildren, consistent with earlier studies from Samoa. Interpretation This study describes a considerable burden of disease attributed to impetigo and scabies in Samoa. These findings will be valuable in addressing the public health challenge posed by these conditions, providing baseline prevalence data and highlighting practical strategies to reduce transmission of relevant microbes and parasites in this setting. Tala Tomua O a'afiaga o le pa'u i fa'ama'i o le po'u (impetigo) ma le utu o le pa'u (scabies), ua tele naua le fanau ua maua ai i le pasefika, ma le lalolagi atoa. O fuafuaga vaai mamao ma polokalame e fofoina ai nei faafitauli, e aofia ai le inumaga o fualaau e tapeina ai nei fa'ama'i, ua aliali mai ai e mafai ona faatamaia nei fa'ama'i. E le o tele ni tusitusiga ma faamaumauga i totonu o Samoa, pe ta'atele nei fa'amai o le pa'u pe leai. Ona o le le faatauaina o nei fa'ama'i, e le o iloa fo'i ni mafuaga ma nisi tulaga e faateleina ai nei fa'ama'i o le pa'u i Samoa. Faatinoina o le suesuega O le suesuega faasaenisi i le fanau aoga i le va o le 4 ma le 15 tausaga o loo ao'oga i le tulaga lua i nisi o nu'u i tua i Upolu, na faatinoina ai suesuega lea, ia suesueina ai le aotelega ma fainumera o le fanau ua maua i fa'ama'I o le po'u (impetigo) ma le utu o le pa'u (scabies). O lenei foi suesuega, na fia iloa ai fo'i po'o a ituaiga siama eseese o loo maua i luga o pa'u ma tino o le fanau aoga, ina ia iloa ai foi auala ua pipisi ai nei siama mai le isi tamaitiiti i le isi, ona mafua ai lea o nei fa'ama'i o le pa'u. Tanuuga o le suesuega Ua faailoa mai i le suesuega, le ta'atele o le fa'ama'i o le po'u (impetigo) ua maua ai le fanau aoga (57%), i aoga na faia ai le suesuega. O se fainumera ua maualuga tele i le lalolagi atoa. E toatele atu nisi o le fanau laiti (younger) ma tama (male) e maua i le po'u nai lo isi tamaiti. O le fainumera o le utu o le pa'u (scabies) (14·4%) e tai tutusa lava ma isi motu o le Pasefika. O le feaveaina o le siama faapitoa (staph aureus) ua tupu lea i le fanau ua ao'oga i le aoga e tasi. E le toatele foi nisi o le fanau (2%) na maua i le siama faapitoa o le fa'ai (strep pyogenes) e ona mafua ai le fiva rumatika. O lenei fainumera ua tai tutusa ma suesuega faasaenisi na fai muamua i Samoa. Aotelega O le aotelega la o lenei suesuega faasaenisi, ua faailoaina mai ai le tele naua o le fa'ama'i o le pa'u, o po'u (impetigo) ma le utu o le pa'u (scabies) i Samoa nei. O nei foi suesuega o le a aoga tele ini polokalame ma ni fuafuaga mamao e fa'afoisia ai nei faafitauli i le soifua maloloina o le fanau i Samoa. O le a avea foi nei fainumera e faamaumauina mo le silafia e le atunuu ma le soifua maloloina, le ta'atele o nei fa'amai o le pa'u, mo le tapenaina o ni fofo talafeagai ise taimi o i luma, ina ia faaitiitina ai le pipisi o nei siami i fanau ao'oga i Samoa.
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Affiliation(s)
- George Taiaroa
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Australia
| | - Ben Matalavea
- Faculty of Medicine, National University of Samoa, Apia, Samoa.,National Kidney Foundation of Samoa, Apia, Samoa
| | - Malama Tafuna'i
- Centre for Pacific Health, Division of Health Sciences, The University of Otago, Dunedin, New Zealand
| | - Jake A Lacey
- Doherty Department at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria, Australia
| | - David J Price
- Victorian Infectious Diseases Reference Laboratory Epidemiology Unit, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Victoria, Australia
| | - Lupeoletalalelei Isaia
- Tupua Tamasese Mea'ole National Hospital Laboratory, Samoa Ministry of Health, Apia, Samoa
| | - Hinauri Leaupepe
- Tupua Tamasese Mea'ole National Hospital Laboratory, Samoa Ministry of Health, Apia, Samoa
| | | | - Darren Lee
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Claire L Gorrie
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Deborah A Williamson
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Australia.,Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Susan Jack
- Department of Preventive and Social Medicine, University of Otago, New Zealand.,Public Health Unit, Southern District Health Board, Dunedin, New Zealand
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22
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Dooley LM, Ahmad TB, Pandey M, Good MF, Kotiw M. Rheumatic heart disease: A review of the current status of global research activity. Autoimmun Rev 2020; 20:102740. [PMID: 33333234 DOI: 10.1016/j.autrev.2020.102740] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/04/2020] [Indexed: 01/17/2023]
Abstract
Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.
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Affiliation(s)
- Leanne M Dooley
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Tarek B Ahmad
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Manisha Pandey
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael F Good
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael Kotiw
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
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23
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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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Subdominance in Antibody Responses: Implications for Vaccine Development. Microbiol Mol Biol Rev 2020; 85:85/1/e00078-20. [PMID: 33239435 DOI: 10.1128/mmbr.00078-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vaccines work primarily by eliciting antibodies, even when recovery from natural infection depends on cellular immunity. Large efforts have therefore been made to identify microbial antigens that elicit protective antibodies, but these endeavors have encountered major difficulties, as witnessed by the lack of vaccines against many pathogens. This review summarizes accumulating evidence that subdominant protein regions, i.e., surface-exposed regions that elicit relatively weak antibody responses, are of particular interest for vaccine development. This concept may seem counterintuitive, but subdominance may represent an immune evasion mechanism, implying that the corresponding region potentially is a key target for protective immunity. Following a presentation of the concepts of immunodominance and subdominance, the review will present work on subdominant regions in several major human pathogens: the protozoan Plasmodium falciparum, two species of pathogenic streptococci, and the dengue and influenza viruses. Later sections are devoted to the molecular basis of subdominance, its potential role in immune evasion, and general implications for vaccine development. Special emphasis will be placed on the fact that a whole surface-exposed protein domain can be subdominant, as demonstrated for all of the pathogens described here. Overall, the available data indicate that subdominant protein regions are of much interest for vaccine development, not least in bacterial and protozoal systems, for which antibody subdominance remains largely unexplored.
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25
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The emm-Cluster Typing System. Methods Mol Biol 2020. [PMID: 32430811 DOI: 10.1007/978-1-0716-0467-0_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
emm-cluster typing system allows to classify most Streptococcus pyogenes variants into 48 different emm clusters. The system correlates nicely with the host serum binding capacities of the M proteins and has been used in epidemiological surveys, strain selection, and vaccine development. Here we describe the allocation of the emm cluster based on the emm-typing defining region.
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