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Harris K, Proctor LK, Shinar S, Philippopoulos E, Yudin MH, Murphy KE. Outcomes and management of pregnancy and puerperal group A streptococcal infections: A systematic review. Acta Obstet Gynecol Scand 2023; 102:138-157. [PMID: 36636775 PMCID: PMC9889326 DOI: 10.1111/aogs.14500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/03/2022] [Accepted: 12/06/2022] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Group A streptococcus (Streptococcus pyogenes) is one of the most lethal bacterial pathogens of humans, with increased risk of progression to septic shock and multiorgan failure in the pregnant population. The objective of this study is to systematically review the outcomes and management strategies for pregnancy and puerperal group A streptococcus infections in an effort to provide further guidance for prevention and treatment of a rare but lethal infection worldwide. MATERIAL AND METHODS A comprehensive search using puerperium and streptococcus pyogenes terms was completed across several registered databases. A total of 902 articles investigating pregnancy and puerperal group A streptococcus infection were identified, with 40 studies fulfilling inclusion criteria of original research articles in humans published from 1990 onwards reporting four or more unique cases of group A streptococcus in pregnancy or postpartum. This study was registered in PROSPERO: CRD42020198983. RESULTS A total of 1160 patients with pregnancy and puerperal group A streptococcus infection were identified. Most infections occurred postpartum (91.9%), with 4.7% reported antepartum and 0.6% intrapartum. Bacteremia was present in 49.0% of patients and endometritis in 45.9%. Puerperal sepsis was described in 28.2% of cases and progressed to streptococcal toxic shock syndrome in one-third of such cases. Overall, the case fatality ratio was 2.0%, with one-third of the deaths from antenatal cases including 3/22 (13.6%) cases of septic abortion and 10/46 (21.7%) antenatal cases of group A streptococcus infection. CONCLUSIONS Group A streptococcus infection remains an important contributor to pregnancy and puerperal morbidity and mortality. Early recognition, diagnosis and aggressive management are important for favorable outcomes given the serious risk of sepsis and streptococcal toxic shock syndrome.
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Affiliation(s)
- Kristin Harris
- Division of Maternal Fetal Medicine, Department of Obstetrics and GynecologySt. Michael's Hospital, University of TorontoTorontoOntarioCanada
| | - Leslie K. Proctor
- Department of Obstetrics and GynecologyUniversity of TorontoTorontoOntarioCanada
| | - Shiri Shinar
- Division of Maternal Fetal Medicine, Department of Obstetrics and GynecologyMount Sinai Hospital, University of TorontoTorontoOntarioCanada
| | | | - Mark H. Yudin
- Department of Obstetrics and GynecologySt. Michael's Hospital, University of TorontoTorontoOntarioCanada
| | - Kellie E. Murphy
- Division of Maternal Fetal Medicine, Department of Obstetrics and GynecologyMount Sinai Hospital, University of TorontoTorontoOntarioCanada
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Abstract
Streptococcus pyogenes is known to cause both mucosal and systemic infections in humans. In this study, we used a combination of quantitative and structural mass spectrometry techniques to determine the composition and structure of the interaction network formed between human plasma proteins and the surfaces of different S. pyogenes serotypes. Quantitative network analysis revealed that S. pyogenes forms serotype-specific interaction networks that are highly dependent on the domain arrangement of the surface-attached M protein. Subsequent structural mass spectrometry analysis and computational modeling of one of the M proteins, M28, revealed that the network structure changes across different host microenvironments. We report that M28 binds secretory IgA via two separate binding sites with high affinity in saliva. During vascular leakage mimicked by increasing plasma concentrations in saliva, the binding of secretory IgA was replaced by the binding of monomeric IgA and C4b-binding protein (C4BP). This indicates that an upsurge of C4BP in the local microenvironment due to damage to the mucosal membrane drives the binding of C4BP and monomeric IgA to M28. These results suggest that S. pyogenes has evolved to form microenvironment-dependent host-pathogen protein complexes to combat human immune surveillance during both mucosal and systemic infections. IMPORTANCEStreptococcus pyogenes (group A Streptococcus [GAS]), is a human-specific Gram-positive bacterium. Each year, the bacterium affects 700 million people globally, leading to 160,000 deaths. The clinical manifestations of S. pyogenes are diverse, ranging from mild and common infections like tonsillitis and impetigo to life-threatening systemic conditions such as sepsis and necrotizing fasciitis. S. pyogenes expresses multiple virulence factors on its surface to localize and initiate infections in humans. Among all these expressed virulence factors, the M protein is the most important antigen. In this study, we perform an in-depth characterization of the human protein interactions formed around one of the foremost human pathogens. This strategy allowed us to decipher the protein interaction networks around different S. pyogenes strains on a global scale and to compare and visualize how such interactions are mediated by M proteins.
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Duane TM, Huston JM, Collom M, Beyer A, Parli S, Buckman S, Shapiro M, McDonald A, Diaz J, Tessier JM, Sanders J. Surgical Infection Society 2020 Updated Guidelines on the Management of Complicated Skin and Soft Tissue Infections. Surg Infect (Larchmt) 2021; 22:383-399. [PMID: 33646051 DOI: 10.1089/sur.2020.436] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Background: The Surgical Infection Society (SIS) Guidelines for the treatment of complicated skin and soft tissue infections (SSTIs) were published in October 2009 in Surgical Infections. The purpose of this project was to provide a succinct update on the earlier guidelines based on an additional decade of data. Methods: We reviewed the previous guidelines eliminating bite wounds and diabetic foot infections including their associated references. Relevant articles on the topic of complicated SSTIs from 2008-2020 were reviewed and graded individually. Comparisons were then made between the old and the new graded recommendations with review of the older references by two authors when there was disparity between the grades. Results: The majority of new studies addressed antimicrobial options and duration of therapy particularly in complicated abscesses. There were fewer updated studies on diagnosis and specific operative interventions. Many of the topics addressed in the original guidelines had no new literature to evaluate. Conclusions: Most recommendations remain unchanged from the original guidelines with the exception of increased support for adjuvant antimicrobial therapy after drainage of complex abscess and increased data for the use of alternative antimicrobial agents.
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Affiliation(s)
| | - Jared M Huston
- Departments of Surgery and Science Education, Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, USA
| | | | - Adam Beyer
- Department of Surgery, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sara Parli
- Department of Pharmacy Services, University of Kentucky, Lexington, Kentucky, USA
| | - Sara Buckman
- Department of Surgery, Washington University, St. Louis, Missouri, USA
| | - Mark Shapiro
- Acute Care Surgery, Portsmouth, New Hampshire, USA
| | - Amy McDonald
- Department of Veterans Affairs, Cleveland, Ohio, USA
| | - Jose Diaz
- Department of Surgery, University of Maryland, Baltimore, Maryland, USA
| | - Jeffrey M Tessier
- Division of Infectious Diseases, University of Texas Southwestern, Dallas Texas, USA
| | - James Sanders
- Department of Pharmacy and Division of Infectious Diseases, University of Texas Southwestern, Dallas, Texas, USA
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Genome-Wide Screens Identify Group A Streptococcus Surface Proteins Promoting Female Genital Tract Colonization and Virulence. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:862-873. [PMID: 32200972 DOI: 10.1016/j.ajpath.2019.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/04/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023]
Abstract
Group A streptococcus (GAS) is a major pathogen that impacts health and economic affairs worldwide. Although the oropharynx is the primary site of infection, GAS can colonize the female genital tract and cause severe diseases, such as puerperal sepsis, neonatal infections, and necrotizing myometritis. Our understanding of how GAS genes contribute to interaction with the primate female genital tract is limited by the lack of relevant animal models. Using two genome-wide transposon mutagenesis screens, we identified 69 GAS genes required for colonization of the primate vaginal mucosa in vivo and 96 genes required for infection of the uterine wall ex vivo. We discovered a common set of 39 genes important for GAS fitness in both environments. They include genes encoding transporters, surface proteins, transcriptional regulators, and metabolic pathways. Notably, the genes that encode the surface-exclusion protein (SpyAD) and the immunogenic secreted protein 2 (Isp2) were found to be crucial for GAS fitness in the female primate genital tract. Targeted gene deletion confirmed that isogenic mutant strains ΔspyAD and Δisp2 are significantly impaired in ability to colonize the primate genital tract and cause uterine wall pathologic findings. Our studies identified novel GAS genes that contribute to female reproductive tract interaction that warrant translational research investigation.
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McNitt DH, Van De Water L, Marasco D, Berisio R, Lukomski S. Streptococcal Collagen-like Protein 1 Binds Wound Fibronectin: Implications in Pathogen Targeting. Curr Med Chem 2019; 26:1933-1945. [PMID: 30182848 DOI: 10.2174/0929867325666180831165704] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/18/2018] [Accepted: 06/28/2018] [Indexed: 02/01/2023]
Abstract
Group A Streptococcus (GAS) infections are responsible for significant morbidity and mortality worldwide. The outlook for an effective global vaccine is reduced because of significant antigenic variation among GAS strains worldwide. Other challenges in GAS therapy include the lack of common access to antibiotics in developing countries, as well as allergy to and treatment failures with penicillin and increasing erythromycin resistance in the industrialized world. At the portal of entry, GAS binds to newly deposited extracellular matrix, which is rich in cellular fibronectin isoforms with extra domain A (EDA, also termed EIIIA) via the surface adhesin, the streptococcal collagen-like protein 1 (Scl1). Recombinant Scl1 constructs, derived from diverse GAS strains, bind the EDA loop segment situated between the C and C' β-strands. Despite the sequence diversity in Scl1 proteins, multiple sequence alignments and secondary structure predictions of Scl1 variants, as well as crystallography and homology modeling studies, point to a conserved mechanism of Scl1-EDA binding. We propose that targeting this interaction may prevent the progression of infection. A synthetic cyclic peptide, derived from the EDA C-C' loop, binds to recombinant Scl1 with a micromolar dissociation constant. This review highlights the current concept of EDA binding to Scl1 and provides incentives to exploit this binding to treat GAS infections and wound colonization.
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Affiliation(s)
- Dudley H McNitt
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, 2095 Health Sciences North, Morgantown, WV 26506, United States
| | - Livingston Van De Water
- Departments of Surgery and Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, United States
| | - Daniela Marasco
- Department of Pharmacy, University of Naples Frederico II, Naples, Italy
| | - Rita Berisio
- Institute of Biostructures and Bioimaging, National Research Council, via Mezzocannone, 16, 80134, Naples, Italy
| | - Slawomir Lukomski
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, 2095 Health Sciences North, Morgantown, WV 26506, United States
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RocA Has Serotype-Specific Gene Regulatory and Pathogenesis Activities in Serotype M28 Group A Streptococcus. Infect Immun 2018; 86:IAI.00467-18. [PMID: 30126898 DOI: 10.1128/iai.00467-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2018] [Indexed: 12/21/2022] Open
Abstract
Serotype M28 group A streptococcus (GAS) is a common cause of infections such as pharyngitis ("strep throat") and necrotizing fasciitis ("flesh-eating" disease). Relatively little is known about the molecular mechanisms underpinning M28 GAS pathogenesis. Whole-genome sequencing studies of M28 GAS strains recovered from patients with invasive infections found an unexpectedly high number of missense (amino acid-changing) and nonsense (protein-truncating) polymorphisms in rocA (regulator of Cov), leading us to hypothesize that altered RocA activity contributes to M28 GAS molecular pathogenesis. To test this hypothesis, an isogenic rocA deletion mutant strain was created. Transcriptome sequencing (RNA-seq) analysis revealed that RocA inactivation significantly alters the level of transcripts for 427 and 323 genes at mid-exponential and early stationary growth phases, respectively, including genes for 41 transcription regulators and 21 virulence factors. In contrast, RocA transcriptomes from other GAS M protein serotypes are much smaller and include fewer transcription regulators. The rocA mutant strain had significantly increased secreted activity of multiple virulence factors and grew to significantly higher colony counts under acid stress in vitro RocA inactivation also significantly increased GAS virulence in a mouse model of necrotizing myositis. Our results demonstrate that RocA is an important regulator of transcription regulators and virulence factors in M28 GAS and raise the possibility that naturally occurring polymorphisms in rocA in some fashion contribute to human invasive infections caused by M28 GAS strains.
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Chua WC, Mazlan MZ, Ali S, Che Omar S, Wan Hassan WMN, Seevaunnantum SP, Mohd Zaini RH, Hassan MH, Muhd Besari A, Abd Rahman Z, Salmuna Ayub ZN, Abd Ghani S, Yaacob N, Wan Rosli WR. Post-partum streptococcal toxic shock syndrome associated with necrotizing fasciitis. IDCases 2017; 9:91-94. [PMID: 28725564 PMCID: PMC5506869 DOI: 10.1016/j.idcr.2017.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 05/04/2017] [Accepted: 05/04/2017] [Indexed: 01/22/2023] Open
Abstract
We report a fatal case of post-partum streptococcal toxic shock syndrome in a patient who was previously healthy and had presented to the emergency department with an extensive blistering ecchymotic lesions over her right buttock and thigh associated with severe pain. The pregnancy had been uncomplicated, and the mode of delivery had been spontaneous vaginal delivery with an episiotomy. She was found to have septicemic shock requiring high inotropic support. Subsequently, she was treated for necrotizing fasciitis, complicated by septicemic shock and multiple organ failures. A consensus was reached for extensive wound debridement to remove the source of infection; however, this approach was abandoned due to the patient's hemodynamic instability and the extremely high risks of surgery. Both the high vaginal swab and blister fluid culture revealed Group A beta hemolytic streptococcus infection. Intravenous carbapenem in combination with clindamycin was given. Other strategies attempted for streptococcal toxic removal included continuous veno-venous hemofiltration and administration of intravenous immunoglobulin. Unfortunately, the patient's condition worsened, and she succumbed to death on day 7 of hospitalization.
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Affiliation(s)
- Wei Chuan Chua
- Department of Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Mohd Zulfakar Mazlan
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Saedah Ali
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Sanihah Che Omar
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Wan Mohd Nazaruddin Wan Hassan
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - S Praveena Seevaunnantum
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Rhendra Hardy Mohd Zaini
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Mohd Hasyizan Hassan
- Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Alwi Muhd Besari
- Department of Internal Medicine, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Zaidah Abd Rahman
- Department of Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Zeti Norfidiyati Salmuna Ayub
- Department of Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Sabrina Abd Ghani
- Department of Orthopaedic, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Normalinda Yaacob
- Department of Emergency Medicine, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Wan Rosilawati Wan Rosli
- Department of Obstetrics & Gynaecology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
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Naseer U, Steinbakk M, Blystad H, Caugant DA. Epidemiology of invasive group A streptococcal infections in Norway 2010–2014: A retrospective cohort study. Eur J Clin Microbiol Infect Dis 2016; 35:1639-48. [DOI: 10.1007/s10096-016-2704-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/03/2016] [Indexed: 11/29/2022]
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Complete Genome Sequence of emm28 Type Streptococcus pyogenes MEW123, a Streptomycin-Resistant Derivative of a Clinical Throat Isolate Suitable for Investigation of Pathogenesis. GENOME ANNOUNCEMENTS 2016; 4:4/2/e00136-16. [PMID: 26988051 PMCID: PMC4796130 DOI: 10.1128/genomea.00136-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
We present here the complete genome sequence of Streptococcus pyogenes type emm28 strain MEW123, a streptomycin-resistant derivative of a pediatric throat isolate. The genome length is 1,878,699 bp, with 38.29% G+C% content. The genome sequence adds value to this virulent emm28 representative strain and will aid in the investigation of streptococcal pathogenesis.
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Watson ME, Nielsen HV, Hultgren SJ, Caparon MG. Murine vaginal colonization model for investigating asymptomatic mucosal carriage of Streptococcus pyogenes. Infect Immun 2013; 81:1606-17. [PMID: 23460515 PMCID: PMC3648019 DOI: 10.1128/iai.00021-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 02/21/2013] [Indexed: 11/20/2022] Open
Abstract
While many virulence factors promoting Streptococcus pyogenes invasive disease have been described, specific streptococcal factors and host properties influencing asymptomatic mucosal carriage remain uncertain. To address the need for a refined model of prolonged S. pyogenes asymptomatic mucosal colonization, we have adapted a preestrogenized murine vaginal colonization model for S. pyogenes. In this model, derivatives of strains HSC5, SF370, JRS4, NZ131, and MEW123 established a reproducible, asymptomatic colonization of the vaginal mucosa over a period of typically 3 to 4 weeks' duration at a relatively high colonization efficiency. Prior treatment with estradiol prolonged streptococcal colonization and was associated with reduced inflammation in the colonized vaginal epithelium as well as a decreased leukocyte presence in vaginal fluid compared to the levels of inflammation and leukocyte presence in non-estradiol-treated control mice. The utility of our model for investigating S. pyogenes factors contributing to mucosal carriage was verified, as a mutant with a mutation in the transcriptional regulator catabolite control protein A (CcpA) demonstrated significant impairment in vaginal colonization. An assessment of in vivo transcriptional activity in the CcpA(-) strain for several known CcpA-regulated genes identified significantly elevated transcription of lactate oxidase (lctO) correlating with excessive generation of hydrogen peroxide to self-lethal levels. Deletion of lctO did not impair colonization, but deletion of lctO in a CcpA(-) strain prolonged carriage, exceeding even that of the wild-type strain. Thus, while LctO is not essential for vaginal colonization, its dysregulation is deleterious, highlighting the critical role of CcpA in promoting mucosal colonization. The vaginal colonization model should prove effective for future analyses of S. pyogenes mucosal colonization.
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Affiliation(s)
- Michael E. Watson
- Divison of Pediatric Infectious Diseases, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hailyn V. Nielsen
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
| | - Scott J. Hultgren
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael G. Caparon
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
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Steer AC, Lamagni T, Curtis N, Carapetis JR. Invasive group a streptococcal disease: epidemiology, pathogenesis and management. Drugs 2012; 72:1213-27. [PMID: 22686614 PMCID: PMC7100837 DOI: 10.2165/11634180-000000000-00000] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Invasive group A streptococcal infections are uncommon, although serious, infections with high case fatality rates. Periodic resurgences in invasive group A streptococcal infections in industrialized countries have been reported from the 1980s onwards, with current estimates of incidence in these countries of approximately 3–4 per 100000 population. Infants, pregnant women and the elderly are at increased risk of invasive group A streptococcal infection. The group A streptococcus has an array of virulence factors that underpin its invasive capacity and, in approximately 10% of cases, super-antigen toxins produced by the bacteria stimulate a large proportion of T cells, leading to streptococcal toxic shock syndrome. Given the rapid clinical progression, effective management of invasive group A streptococcal infections hinges on early recognition of the disease and prompt initiation of supportive care (often intensive care) together with antibacterial therapy. In cases of toxic shock syndrome, it is often difficult to distinguish between streptococcal and staphylococcal infection before cultures become available and so antibacterial choice must include coverage of both of these organisms. In addition, clindamycin is an important adjunctive antibacterial because of its anti-toxin effects and excellent tissue penetration. Early institution of intravenous immunoglobulin therapy should be considered in cases of toxic shock syndrome and severe invasive infection, including necrotizing fasciitis. Early surgical debridement of necrotic tissue is also an important part of management in cases of necrotizing fasciitis.
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Affiliation(s)
- Andrew C Steer
- Centre for International Child Health, Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.
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12
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Steer AC, Lamagni T, Curtis N, Carapetis JR. Invasive group a streptococcal disease: epidemiology, pathogenesis and management. Drugs 2012. [PMID: 22686614 DOI: 10.2165/11634180-000000000-00000)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Invasive group A streptococcal infections are uncommon, although serious, infections with high case fatality rates. Periodic resurgences in invasive group A streptococcal infections in industrialized countries have been reported from the 1980s onwards, with current estimates of incidence in these countries of approximately 3-4 per 100 000 population. Infants, pregnant women and the elderly are at increased risk of invasive group A streptococcal infection. The group A streptococcus has an array of virulence factors that underpin its invasive capacity and, in approximately 10% of cases, superantigen toxins produced by the bacteria stimulate a large proportion of T cells, leading to streptococcal toxic shock syndrome. Given the rapid clinical progression, effective management of invasive group A streptococcal infections hinges on early recognition of the disease and prompt initiation of supportive care (often intensive care) together with antibacterial therapy. In cases of toxic shock syndrome, it is often difficult to distinguish between streptococcal and staphylococcal infection before cultures become available and so antibacterial choice must include coverage of both of these organisms. In addition, clindamycin is an important adjunctive antibacterial because of its anti-toxin effects and excellent tissue penetration. Early institution of intravenous immunoglobulin therapy should be considered in cases of toxic shock syndrome and severe invasive infection, including necrotizing fasciitis. Early surgical debridement of necrotic tissue is also an important part of management in cases of necrotizing fasciitis.
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Affiliation(s)
- Andrew C Steer
- Centre for International Child Health, Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.
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Rantala S, Vähäkuopus S, Siljander T, Vuopio J, Huhtala H, Vuento R, Syrjänen J. Streptococcus pyogenes bacteraemia, emm types and superantigen profiles. Eur J Clin Microbiol Infect Dis 2011; 31:859-65. [PMID: 21877175 DOI: 10.1007/s10096-011-1385-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 08/11/2011] [Indexed: 10/17/2022]
Abstract
The aim of this study was to investigate the emm types and superantigen profiles of bacteraemic group A streptococcal (GAS; Streptococcus pyogenes) isolates and to detect possible associations between the molecular characteristics of isolates and the clinical presentations of disease. In this population-based study, 87 bacteraemic GAS isolates from adult patients in Pirkanmaa Health District (HD), Finland, during the period 1995-2004 were emm typed and genotyped for superantigen (SAg) profiles. The epidemiological and clinical data of the patients were analysed with the microbiological characterisation data. Among the 87 isolates, 18 different emm types were found. emm1, emm28 and emm81 were the three most common types, covering 52% of isolates. The prevalence of specific emm types showed high variability during the 10-year study period. We could not find any association between the emm type and clinical features of bacteraemic infection, such as underlying diseases, disease manifestations or case fatality. Of nine superantigen genes examined, speA and speC were identified in 20 and 30% of the strains, respectively. No association was found between disease manifestation and the presence of single superantigen genes. The 26-valent GAS vaccine would have covered only 62% of isolates causing invasive disease in Pirkanmaa HD during the study period.
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Affiliation(s)
- S Rantala
- Department of Internal Medicine, Tampere University Hospital, P.O. Box 2000, 33521, Tampere, Finland.
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Strus M, Drzewiecki A, Chmielarczyk A, Tomusiak A, Romanek P, Kosowski K, Kochan P, van der Linden M, Lütticken R, Heczko P. Microbiological investigation of a hospital outbreak of invasive group A streptococcal disease in Krakow, Poland. Clin Microbiol Infect 2010. [DOI: 10.1111/j.1469-0691.2010.03139.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Meisal R, Andreasson IKG, Høiby EA, Aaberge IS, Michaelsen TE, Caugant DA. Streptococcus pyogenes isolates causing severe infections in Norway in 2006 to 2007: emm types, multilocus sequence types, and superantigen profiles. J Clin Microbiol 2010; 48:842-51. [PMID: 20042624 PMCID: PMC2832411 DOI: 10.1128/jcm.01312-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 08/21/2009] [Accepted: 12/17/2009] [Indexed: 11/20/2022] Open
Abstract
To investigate the epidemiological patterns and genetic characteristics of disease caused by group A Streptococcus (GAS), all available isolates from invasive cases in Norway during 2006 to 2007 (262 isolates) were subjected to antimicrobial susceptibility testing, T serotyping, emm typing, and multilocus sequence typing and screened for known streptococcal pyrogenic exotoxin (Spe) genes, smeZ, and ssa. The average incidence rate was 3.1 cases per 100,000 individuals. The most prevalent sequence types (STs) were STs 52, 28, and 334. In association with emm types 28, 77, and 87, the serotype T-28 comprised 24.8% of the strains. emm types 28, 1, and 82 were dominating. In 2007, a sharp increase in the number of emm-6 strains was noted. All strains were sensitive to penicillin and quinupristin-dalfopristin, while 3.4% and 6.1% of the strains were resistant to macrolides and tetracycline, respectively. Furthermore, the emm-6 strains had intermediate susceptibility to ofloxacin. Isolates displayed a wide variety of gene profiles, as shown by the presence or absence of the Spe genes, smeZ, and ssa, but 48% of the isolates fell into one of three profiles. In most cases, an emm type was restricted to one gene profile. Although the incidence decreased during this study, invasive GAS disease still has a high endemic rate, with involvement of both established and emerging emm types displaying variability in virulence gene profiles as well as differences in gender and age group preferences.
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Affiliation(s)
- Roger Meisal
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Ida K. G. Andreasson
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
| | - E. Arne Høiby
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Ingeborg S. Aaberge
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Terje E. Michaelsen
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Dominique A. Caugant
- Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Department of Oral Biology, School of Pharmacy, University of Oslo, Oslo, Norway
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16
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Vikerfors A, Haggar A, Darenberg J, Low A, Melhus A, Hedlund J, Sylvan S, Norrby-Teglund A, Eriksson BM. Severe group A streptococcal infections in Uppsala County, Sweden: clinical and molecular characterization of a case cluster from 2006 to 2007. ACTA ACUST UNITED AC 2010; 41:823-30. [PMID: 19922064 DOI: 10.3109/00365540903179749] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study describes a recent cluster of 30 patients (median age 52 years) with serious group A streptococcal (GAS) infections in Uppsala County, Sweden, from December 2006 to May 2007. Patients hospitalized with a severe GAS infection, i.e. cases with either invasive GAS (iGAS) disease or patients with a positive non-sterile site culture/rapid antigen test for GAS and clinically considered as having a critical disease, were included in the study. Common clinical presentations were skin and soft tissue infections (53%) and pneumonia (17%). Eight patients (27%) were diagnosed with streptococcal toxic shock syndrome. In 40% of the cases no relevant underlying disease was reported. Among the 16 patients with soft tissue infections, the upper chest, neck or upper arm area was frequently affected and the infection was associated with severe pain. Among the 20 collected isolates, the T1/emm1 type dominated (80%). The majority (86%) of 7 analysed acute sera lacked neutralizing activity against superantigens produced by the patients' own infecting isolate. The study underscores the association between T1/emm1 and outbreaks of serious GAS infections. This highlights the importance of surveillance for prompt identification of more aggressive isolates in the community, thereby increasing awareness among healthcare professionals of these life-threatening infections.
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Affiliation(s)
- Anna Vikerfors
- Department Infectious Diseases, Uppsala University Hospital, Uppsala, Sweden.
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17
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Silva-Costa C, Pinto FR, Ramirez M, Melo-Cristino J. Decrease in macrolide resistance and clonal instability among Streptococcus pyogenes in Portugal. Clin Microbiol Infect 2008; 14:1152-9. [PMID: 19046174 DOI: 10.1111/j.1469-0691.2008.02104.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Macrolide resistance among Streptococcus pyogenes (group A streptococci) in Portugal was stable during 1998-2003, but a rapid inversion in the dominant phenotypes was noted in the same period, with a sharp decrease in the proportion of isolates presenting the MLS(B) phenotype and a concomitant increase in isolates presenting the M phenotype. The characterization of group A streptococci recovered during 2004-2006, which is reported here, revealed that resistance was not stable during this period and that the decline in erythromycin resistance observed during 2004-2006 was due to a decrease in the prevalence of isolates presenting the M phenotype, while the proportion of isolates expressing the MLS(B) phenotype remained stable. Characterization by emm typing, T serotyping, pulsed-field gel electrophoresis (PFGE) profiling and multilocus sequence typing revealed a very diverse population. Several of the major PFGE clusters identified had already been found in the 1998-2003 study period, but others were found for the first time, e.g. T11/emm11/ST403, carrying the erm(B) gene, and T3/13/emm3/ST315, carrying the mef(A) gene. The clone defined as T12/emm12/ST36, previously found to be associated with mef(A), was now found to be predominantly associated with erm(B). The clonal dynamics of macrolide-resistant group A streptococci emphasizes the importance of considering factors other than antibiotic consumption in explaining the prevalence of resistant isolates.
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Affiliation(s)
- C Silva-Costa
- Institute of Microbiology/Molecular Medicine, Faculty of Medicine, Lisbon University, Lisbon, Portugal
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18
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Lamagni TL, Neal S, Keshishian C, Alhaddad N, George R, Duckworth G, Vuopio-Varkila J, Efstratiou A. Severe Streptococcus pyogenes infections, United Kingdom, 2003-2004. Emerg Infect Dis 2008; 14:202-9. [PMID: 18258111 PMCID: PMC2600190 DOI: 10.3201/eid1402.070888] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Epidemiology of severe disease caused by this organism has changed, with increased incidence and different risk groups. As part of a Europe-wide initiative to explore current epidemiologic patterns of severe disease caused by Streptococcus pyogenes, the United Kingdom undertook enhanced population-based surveillance during 2003–2004. A total of 3,775 confirmed cases of severe S. pyogenes infection were identified over 2 years, 3.33/100,000 population, substantially more than previously estimated. Skin/soft tissue infections were the most common manifestation (42%), followed by respiratory tract infections (17%). Injection drug use was identified as a risk factor for 20% of case-patients. One in 5 infected case-patients died within 7 days of diagnosis; the highest mortality rate was for cases of necrotizing fasciitis (34%). Nonsteroidal antiinflammatory drugs, alcoholism, young age, and infection with emm/M3 types were independently associated with increased risk for streptococcal toxic shock syndrome. Understanding the pattern of these diseases and predictors of poor patient outcome will help with identification and assessment of the potential effect of targeted interventions.
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19
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Steer AC, Curtis N, Carapetis JR. Diagnosis and treatment of invasive group A streptococcal infections. ACTA ACUST UNITED AC 2008; 2:289-301. [DOI: 10.1517/17530059.2.3.289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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20
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The intrinsic immunoglobulin g endopeptidase activity of streptococcal Mac-2 proteins implies a unique role for the enzymatically impaired Mac-2 protein of M28 serotype strains. Infect Immun 2008; 76:2183-8. [PMID: 18332209 DOI: 10.1128/iai.01422-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
IdeS, a secreted cysteine protease of the important human pathogen Streptococcus pyogenes, interferes with phagocytic killing by specifically cleaving the heavy chain of immunoglobulin G (IgG). Two allelic variants of the enzyme have been described, the IgG-specific endopeptidase, IdeS (or Mac-1) and Mac-2, a protein with only weak IgG endopeptidase activity, which has been suggested to interfere with opsonophagocytosis by blocking Fcgamma receptors of phagocytic cells. However, despite the fact that Mac-2 proteins interact with Fcgamma receptors, no inhibition of reactive oxygen species (ROS) production, opsonophagocytosis, or streptococcal killing by Mac-2 has been reported. In the present study, Mac-2 proteins are shown to contain IgG endopeptidase activity indistinguishable from the enzymatic activity exhibited by IdeS/Mac-1 proteins. The earlier reported weak IgG endopeptidase activity appears to be unique to Mac-2 of M28 serotype strains (Mac-2(M28)) and is most likely due to the formation of a disulfide bond between the catalytic site cysteine and a cysteine residue in position 257 of Mac-2(M28). Furthermore, Mac-2 proteins are shown to inhibit ROS production ex vivo, independently of the IgG endopeptidase activity of the proteins. Inhibition of ROS generation per se, however, was not sufficient to mediate streptococcal survival in bactericidal assays. Thus, in contrast to earlier studies, implicating separate functions for IdeS and Mac-2 protein variants, the current study suggests that Mac-2 and IdeS are bifunctional proteins, combining Fcgamma receptor binding and IgG endopeptidase activity. This finding implies a unique role for Mac-2 proteins of the M28 serotype, since this serotype has evolved and retained a Mac-2 protein lacking IgG endopeptidase activity.
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21
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Clinical and epidemiological aspects of invasive Streptococcus pyogenes infections in Denmark during 2003 and 2004. J Clin Microbiol 2007; 46:79-86. [PMID: 17959766 DOI: 10.1128/jcm.01626-07] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Active surveillance of invasive group A streptococcal (GAS) infections was conducted in Denmark during 2003 and 2004 as a part of the Strep-EURO initiative. The main objective was to improve understanding of the epidemiology of invasive GAS disease in Denmark. During the 2 years, 278 cases were reported, corresponding to a mean annual incidence of 2.6 cases per 100,000 inhabitants. The vast majority of isolates, 253 (91%), were from blood, with the remaining 25 (9%) being from cerebrospinal fluid, joints, or other normally sterile sites. The mean case fatality rate (CFR) was 20%, with the rate being higher in patients more than 70 years of age (36.5%). For streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis the CFRs were 53% and 25%, respectively. Out of 16 T types recorded, three predominated: T28 (23%), T1 (22%), and the cluster T3/13/B3264 (14%). Among 29 different emm types, emm28 and emm1 accounted for 51% of strains, followed by emm3 (11%), emm89 (7%), and emm12 (5.5%). Low resistance rates were detected for macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (3%) and tetracycline (8%); two isolates exhibited coresistance to tetracycline and macrolides. Of nine pyrogenic exotoxin (superantigen) genes examined, speA and speC were identified in 58% and 40% of the strains, respectively; either of the genes was present in all strains causing STSS. Most strains harbored speG (99%). ssa was present in 14% of the isolates only. In Denmark, as in comparable countries, GAS invasive disease shows a sustained, high endemicity, with involvement of both established and emerging streptococcal emm and T types.
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Silva-Costa C, Ramirez M, Melo-Cristino J. Identification of macrolide-resistant clones of Streptococcus pyogenes in Portugal. Clin Microbiol Infect 2007; 12:513-8. [PMID: 16700698 DOI: 10.1111/j.1469-0691.2006.01408.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although the overall level of macrolide resistance (27%) has remained stable in Portugal, a rapid inversion in the dominant phenotypes has been noted, with a sharp decrease in the MLS(B) phenotype paralleled by an increase in the M phenotype. To gain further insight into these changes, 325 macrolide-resistant isolates were characterised using a combination of pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The use of Cfr9I, an isoschizomer of SmaI, to digest M phenotype isolates that were refractory to SmaI digestion allowed direct comparison of MLS(B) and M isolates. The results from PFGE and MLST were highly concordant and identified eight major clones, accounting for 92% of the isolates, each of which was associated exclusively with a single macrolide resistance phenotype. Two major clones were found among MLS(B) isolates, characterised by sequence types (ST) 46 (T12/emm22) and ST52 (T28/emm28), whereas clones characterised by ST39 (T4/emm4) and ST28 (T1/emm1) dominated among M isolates. The clone defined by ST52 corresponded to a bacitracin-resistant clone circulating in Europe, and a novel variant expressing other surface antigens (T12/emm22) was detected. The presence of the four major clones has been reported previously in other European countries, suggesting Europe-wide dissemination of a few macrolide-resistant lineages.
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Affiliation(s)
- C Silva-Costa
- Laboratório de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Lisboa, Lisbon, Portugal
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23
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Beres SB, Musser JM. Contribution of exogenous genetic elements to the group A Streptococcus metagenome. PLoS One 2007; 2:e800. [PMID: 17726530 PMCID: PMC1949102 DOI: 10.1371/journal.pone.0000800] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Accepted: 07/31/2007] [Indexed: 11/29/2022] Open
Abstract
Variation in gene content among strains of a bacterial species contributes to biomedically relevant differences in phenotypes such as virulence and antimicrobial resistance. Group A Streptococcus (GAS) causes a diverse array of human infections and sequelae, and exhibits a complex pathogenic behavior. To enhance our understanding of genotype-phenotype relationships in this important pathogen, we determined the complete genome sequences of four GAS strains expressing M protein serotypes (M2, M4, and 2 M12) that commonly cause noninvasive and invasive infections. These sequences were compared with eight previously determined GAS genomes and regions of variably present gene content were assessed. Consistent with the previously determined genomes, each of the new genomes is ∼1.9 Mb in size, with ∼10% of the gene content of each encoded on variably present exogenous genetic elements. Like the other GAS genomes, these four genomes are polylysogenic and prophage encode the majority of the variably present gene content of each. In contrast to most of the previously determined genomes, multiple exogenous integrated conjugative elements (ICEs) with characteristics of conjugative transposons and plasmids are present in these new genomes. Cumulatively, 242 new GAS metagenome genes were identified that were not present in the previously sequenced genomes. Importantly, ICEs accounted for 41% of the new GAS metagenome gene content identified in these four genomes. Two large ICEs, designated 2096-RD.2 (63 kb) and 10750-RD.2 (49 kb), have multiple genes encoding resistance to antimicrobial agents, including tetracycline and erythromycin, respectively. Also resident on these ICEs are three genes encoding inferred extracellular proteins of unknown function, including a predicted cell surface protein that is only present in the genome of the serotype M12 strain cultured from a patient with acute poststreptococcal glomerulonephritis. The data provide new information about the GAS metagenome and will assist studies of pathogenesis, antimicrobial resistance, and population genomics.
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Affiliation(s)
- Stephen B. Beres
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - James M. Musser
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, Houston, Texas, United States of America
- * To whom correspondence should be addressed. E-mail:
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24
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Darenberg J, Luca-Harari B, Jasir A, Sandgren A, Pettersson H, Schalén C, Norgren M, Romanus V, Norrby-Teglund A, Normark BH. Molecular and Clinical Characteristics of Invasive Group A Streptococcal Infection in Sweden. Clin Infect Dis 2007; 45:450-8. [PMID: 17638193 DOI: 10.1086/519936] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 05/07/2007] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The incidence and severity of invasive group A streptococcal infection demonstrate great variability over time, which at least, in part, seems to be related to group A streptococcal type distribution among the human population. METHODS An enhanced surveillance study of invasive group A streptococcal infection (746 isolates) was performed in Sweden from April 2002 through December 2004. Noninvasive isolates from either the throat or skin (773 isolates) were collected in parallel for comparison. Clinical and epidemiological data were obtained from 88% of patients with invasive disease and were related to isolate characteristics, including T type, emm sequence type, and the presence of 9 superantigen genes, as well as pulsed-field gel electrophoresis pattern comparisons of selected isolates. RESULTS The annual incidence was 3.0 cases per 100,000 population. Among the patients with invasive disease, 11% developed streptococcal toxic shock syndrome, and 9.5% developed necrotizing fasciitis. The overall case-fatality rate was 14.5%, and 39% of the patients with streptococcal toxic shock syndrome died (P<.001). The T3/13/B3264 cluster accounted for 33% of invasive and 25% of noninvasive isolates. Among this most prevalent type cluster, emm types 89 and 81 dominated. Combined results from pulsed-field gel electrophoresis, emm typing, and superantigen gene profiling identified subgroups within specific emm types that are significantly more prone to cause invasive disease than were other isolates of the same type. CONCLUSIONS This study revealed a changing epidemiology of invasive group A streptococcal infection in Sweden, with emergence of new emm types that were previously not described. The results also suggest that some clones may be particularly prone to cause invasive disease.
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Affiliation(s)
- Jessica Darenberg
- Department of Bacteriology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
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25
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Abstract
The group A streptococcus causes the widest range of disease in humans of all bacterial pathogens. Group A streptococcal diseases are more common in children than adults with diseases ranging from pharyngitis and impetigo to invasive infections and the post-streptococcal sequelae--acute rheumatic fever and acute post-streptococcal glomerulonephritis. The global burden of severe group A streptococcal disease is concentrated largely in developing countries and Indigenous populations such as Aboriginal Australians. Control of group A streptococcal disease is poor in these settings and the need for a vaccine has been argued. With an ever-increasing understanding of the group A streptococcus at a molecular level, new and sophisticated vaccines are currently in human trials and the next decade holds exciting prospects for curbing group A streptococcal diseases.
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Affiliation(s)
- Andrew C Steer
- Centre for International Child Health, University of Melbourne, Department of Paediatrics, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
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26
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Siljander T, Toropainen M, Muotiala A, Hoe NP, Musser JM, Vuopio-Varkila J. emm typing of invasive T28 group A streptococci, 1995-2004, Finland. J Med Microbiol 2006; 55:1701-1706. [PMID: 17108274 DOI: 10.1099/jmm.0.46690-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A total of 985 group A streptococcus (GAS) bacteraemia isolates collected in Finland during 1995-2004 were T-serotyped, and of these, 336 isolates of serotype T28 were subjected to further emm typing. The total number of isolates referred per year showed an increase within the study period, from 43 in 1995 to 130 in 2004. The annual incidence of invasive GAS (iGAS) bacteraemia showed a general increase during the study period, from 1.1 to 2.5 per 100 000 population. Serotype T28 remained among the most common serotypes, in addition to serotypes TB3264 and T1. The serotype T28 isolates were found to be distributed across six distinct emm types: emm28, emm77, emm53 (including subtypes 53.2 and 53.4), emm87, emm2 and emm4. The serotype distribution and the emm type distribution of serotype T28 fluctuated over time. Within the study period, the proportion of T28/emm28 isolates became the most prominent. During periods of low emm28 incidence, emm types 77 and 53 seemed to show a resurgence. emm typing revealed T28 isolates to be a genetically heterogeneous group harbouring a variety of distinct M proteins. This study confirms that T serotyping alone is not a sufficient method for epidemiological surveillance of iGAS.
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Affiliation(s)
- Tuula Siljander
- Hospital Bacteria Laboratory, Department of Bacterial and Inflammatory Diseases, National Public Health Institute, Mannerheimintie 166, FIN-00300, Helsinki, Finland
| | - Maija Toropainen
- Hospital Bacteria Laboratory, Department of Bacterial and Inflammatory Diseases, National Public Health Institute, Mannerheimintie 166, FIN-00300, Helsinki, Finland
| | - Anna Muotiala
- Hospital Bacteria Laboratory, Department of Bacterial and Inflammatory Diseases, National Public Health Institute, Mannerheimintie 166, FIN-00300, Helsinki, Finland
| | - Nancy P Hoe
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT 59840, USA
| | - James M Musser
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, 6565 Fannin Street, Houston, TX 77030, USA
| | - Jaana Vuopio-Varkila
- Hospital Bacteria Laboratory, Department of Bacterial and Inflammatory Diseases, National Public Health Institute, Mannerheimintie 166, FIN-00300, Helsinki, Finland
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27
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Maripuu L, Eriksson A, Eriksson B, Pauksen K, Holm S, Norgren M. Dynamics of the immune response against extracellular products of group A streptococci during infection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 14:44-51. [PMID: 17093101 PMCID: PMC1797706 DOI: 10.1128/cvi.00271-06] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immune response against the infecting group A streptococcus (GAS) extracellular products (EP) was determined in acute- and convalescent-phase sera from 75 patients with different clinical manifestations of GAS infection. All EP elicited a high proliferative response in human peripheral blood mononuclear cells. In patients with bacteremia, low neutralization in acute-phase sera was associated with development of streptococcal toxic shock syndrome. Lack of neutralization in acute-phase sera was more common in patients infected with the T1emm1 serotype. The majority of patients did not develop the ability to neutralize the mitogenic activity of their infecting isolate despite a significant increase in enzyme-linked immunosorbent assay titer in early convalescent-phase sera. In patients with the ability to neutralize GAS EP, the immune response remained high over at least 3 years. In contrast, the neutralization capacity conferred by intravenous immunoglobulin and/or plasma treatment disappeared within 3 months.
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Affiliation(s)
- Linda Maripuu
- Department of Clinical Bacteriology, Umeå University, 901 85 Umeå, Sweden
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28
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Zhang S, Green NM, Sitkiewicz I, Lefebvre RB, Musser JM. Identification and characterization of an antigen I/II family protein produced by group A Streptococcus. Infect Immun 2006; 74:4200-13. [PMID: 16790795 PMCID: PMC1489706 DOI: 10.1128/iai.00493-06] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Group A Streptococcus (GAS) is a gram-positive human bacterial pathogen that causes infections ranging in severity from pharyngitis to life-threatening invasive disease, such as necrotizing fasciitis. Serotype M28 strains are consistently isolated from invasive infections, particularly puerperal sepsis, a severe infection that occurs during or after childbirth. We recently sequenced the genome of a serotype M28 GAS strain and discovered a novel 37.4-kb foreign genetic element designated region of difference 2 (RD2). RD2 is similar in gene content and organization to genomic islands found in group B streptococci (GBS), the major cause of neonatal infections. RD2 encodes seven proteins with conventional gram-positive secretion signal sequences, six of which have not been characterized. Herein, we report that one of these six proteins (M28_Spy1325; Spy1325) is a member of the antigen I/II family of cell surface-anchored molecules produced by oral streptococci. PCR and DNA sequence analysis found that Spy1325 is very well conserved in GAS strains of distinct M protein serotypes. As assessed by real-time TaqMan quantitative PCR, the Spy1325 gene was expressed in vitro, and Spy1325 protein was present in culture supernatants and on the GAS cell surface. Western immunoblotting and enzyme-linked immunosorbent assays indicated that Spy1325 was produced by GAS in infected mice and humans. Importantly, the immunization of mice with recombinant Spy1325 fragments conferred protection against GAS-mediated mortality. Similar to other antigen I/II proteins, recombinant Spy1325 bound purified human salivary agglutinin glycoprotein. Spy1325 may represent a shared virulence factor among GAS, GBS, and oral streptococci.
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Affiliation(s)
- Shizhen Zhang
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, The Methodist Hospital, B154, 6565 Fannin St., Houston, TX 77030, USA
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29
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Pinho MD, Melo-Cristino J, Ramirez M. Clonal relationships between invasive and noninvasive Lancefield group C and G streptococci and emm-specific differences in invasiveness. J Clin Microbiol 2006; 44:841-6. [PMID: 16517864 PMCID: PMC1393098 DOI: 10.1128/jcm.44.3.841-846.2006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lancefield group G and group C streptococci (GGS and GCS, respectively) are pathogens responsible for a number of life-threatening infections. A collection of 116 recent (1998 to 2004) invasive (n = 28) and noninvasive (n = 88) GGS and GCS clinical isolates from Portugal were characterized. All isolates were identified as Streptococcus dysgalactiae subsp. equisimilis and characterized by emm typing and DNA macrorestriction profiling using pulsed-field gel electrophoresis (PFGE). emm typing revealed the presence of 22 distinct types, including 3 novel types. PFGE identified 14 clones with more than two isolates, but over half of the isolates were concentrated in 3 large clones. Individual clones and emm types showed a low level of association, since the majority of the clones included more than one emm type and the same emm type was found among diverse genetic backgrounds. Two emm types, stg2078 and stg10, were significantly more frequent among invasive isolates, and another two, stg6792 and stg166b, were present only in noninvasive isolates, suggesting a correlation between emm type and invasive disease potential.
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Affiliation(s)
- M D Pinho
- Instituto de Microbiologia, Faculdade de Medicina de Lisboa, Av. Prof. Egas Moniz, PT 1649-028 Lisbon, Portugal
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30
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Musser JM, DeLeo FR. Toward a genome-wide systems biology analysis of host-pathogen interactions in group A Streptococcus. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 167:1461-72. [PMID: 16314461 PMCID: PMC1613186 DOI: 10.1016/s0002-9440(10)61232-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Genome-wide analysis of microbial pathogens and molecular pathogenesis processes has become an area of considerable activity in the last 5 years. These studies have been made possible by several advances, including completion of the human genome sequence, publication of genome sequences for many human pathogens, development of microarray technology and high-throughput proteomics, and maturation of bioinformatics. Despite these advances, relatively little effort has been expended in the bacterial pathogenesis arena to develop and use integrated research platforms in a systems biology approach to enhance our understanding of disease processes. This review discusses progress made in exploiting an integrated genome-wide research platform to gain new knowledge about how the human bacterial pathogen group A Streptococcus causes disease. Results of these studies have provided many new avenues for basic pathogenesis research and translational research focused on development of an efficacious human vaccine and novel therapeutics. One goal in summarizing this line of study is to bring exciting new findings to the attention of the investigative pathology community. In addition, we hope the review will stimulate investigators to consider using analogous approaches for analysis of the molecular pathogenesis of other microbes.
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Affiliation(s)
- James M Musser
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, and Department of Pathology, The Methodist Hospital, Houston, TX 77030, USA.
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31
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Green NM, Beres SB, Graviss EA, Allison JE, McGeer AJ, Vuopio-Varkila J, LeFebvre RB, Musser JM. Genetic diversity among type emm28 group A Streptococcus strains causing invasive infections and pharyngitis. J Clin Microbiol 2005; 43:4083-91. [PMID: 16081955 PMCID: PMC1233891 DOI: 10.1128/jcm.43.8.4083-4091.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Genome sequencing of group A Streptococcus (GAS) has revealed that prophages account for the vast majority of gene content differences between strains. Serotype M28 strains are a leading cause of pharyngitis and invasive infections, but little is known about genetic diversity present in natural populations of these organisms. To study this issue, population-based samples of 568 strains from Ontario, Canada; Finland; and Houston, Texas, were analyzed. Special attention was given to analysis of variation in prophage-encoded virulence gene content by a PCR-based method. Thirty and 29 distinct prophage-encoded virulence gene profiles were identified among pharyngitis and invasive infection isolates. Thirteen profiles, representing the majority of the strains, were shared between these two classes of isolates. Significant differences were observed in the frequency of occurrence of certain prophage toxin gene profiles and infection type. M28 strains are highly diverse in prophage-encoded virulence gene content and integration site, supporting the key concept that prophages are critical contributors to GAS genetic diversity and population biology. Nucleotide sequence variation in the emm gene (encodes M protein) was also examined. Only three allelic variants were identified in the hypervariable portion of the emm28 gene. All but one strain had the same inferred amino acid sequence in the first 100 amino acids of the mature M28 protein. In contrast, size differences in the emm28 gene and inferred protein due to variable numbers of C-terminal repeats were common. The presence of macrolide resistance genes (mefA, ermB, and ermTR) was analyzed by PCR, and less than 2% of the strains were positive.
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Affiliation(s)
- Nicole M. Green
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - Stephen B. Beres
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - Edward A. Graviss
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - James E. Allison
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - Allison J. McGeer
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - Jaana Vuopio-Varkila
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - Rance B. LeFebvre
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
| | - James M. Musser
- Center for Human Bacterial Pathogenesis Research, Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, Department of Pathology, Microbiology, and Immunology, University of California—Davis, Davis, California 95616, Pediatric Medical Group, Houston, Texas 77098, Mount Sinai Hospital, Department of Microbiology, University of Toronto, Toronto, Ontario M5G 1X5, Canada, National Public Health Institute, Helsinki, Finland
- Corresponding author. Mailing address: Department of Pathology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030. Phone: (713) 798-3823. Fax: (713) 798-4595. E-mail:
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Ekelund K, Darenberg J, Norrby-Teglund A, Hoffmann S, Bang D, Skinhøj P, Konradsen HB. Variations in emm type among group A streptococcal isolates causing invasive or noninvasive infections in a nationwide study. J Clin Microbiol 2005; 43:3101-9. [PMID: 16000420 PMCID: PMC1169105 DOI: 10.1128/jcm.43.7.3101-3109.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Since the late 1980s several studies have described the increased incidence and severity of invasive group A streptococcal (GAS) infections. However, most studies on GAS pathogenesis have focused on information obtained during outbreaks. We analyzed isolate distribution and host susceptibility as part of a nationwide prospective surveillance study performed between January 2001 and August 2002. GAS isolates collected from 201 patients with invasive infections, 335 patients with noninvasive infections, and 17 asymptomatic carriers were characterized with respect to their emm types and superantigen genotypes. The superantigen-neutralizing capacity and levels of antibodies against streptolysin O and DNAse B were determined for isolates from the sera from 36 invasive cases and 91 noninvasive cases. emm type 1 (emm-1) isolates were significantly more common among invasive cases, whereas emm-4, emm-6, and emm-12 dominated among the noninvasive cases. The distributions of the phage-associated superantigen genes (speA, speC, speH, speI, ssa) differed among invasive and noninvasive isolates, mainly due to their linkage to certain emm types. No significant differences in serum superantigen-neutralizing capacities were observed. The levels of anti-streptolysin O and anti-DNAse B antibodies were highest in the sera from invasive cases. Our study emphasizes the importance of obtaining data during years with stable incidences, which will enable evaluation of future outbreak data.
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Affiliation(s)
- Kim Ekelund
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
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Smith A, Lamagni TL, Oliver I, Efstratiou A, George RC, Stuart JM. Invasive group A streptococcal disease: should close contacts routinely receive antibiotic prophylaxis? THE LANCET. INFECTIOUS DISEASES 2005; 5:494-500. [PMID: 16048718 DOI: 10.1016/s1473-3099(05)70190-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Group A streptococci (Streptococcus pyogenes) causes a wide range of illnesses from non-invasive disease--eg, pharyngitis--to more severe invasive infections--eg, necrotising fasciitis and toxic shock-like syndrome. There remains uncertainty about the risk of secondary cases of invasive disease occurring among close contacts of an index case and how best to manage that risk. We do not consider that currently available evidence justifies the routine administration of chemoprophylaxis to close contacts. We suggest that the appropriate response should be to routinely inform all household contacts of a patient with invasive group A streptococcal disease about the clinical manifestations of invasive disease and to seek immediate medical attention if they develop such symptoms.
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Affiliation(s)
- A Smith
- Health Protection Agency, Centre for Infections, London, UK.
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Tyrrell GJ, Lovgren M, Kress B, Grimsrud K. Invasive group A streptococcal disease in Alberta, Canada (2000 to 2002). J Clin Microbiol 2005; 43:1678-83. [PMID: 15814984 PMCID: PMC1081384 DOI: 10.1128/jcm.43.4.1678-1683.2005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Invasive group A streptococcal (iGAS) disease was placed under surveillance in Alberta in August 1999. The purpose of this study was to determine the incidence rates of iGAS infections throughout Alberta over a 3-year period (2000 to 2002) and to better understand the epidemiology of iGAS in this province. There were a total of 441 cases of invasive GAS disease over the 3 years examined (average population over 3 years, 3,055,765) and 47 deaths. The incidence in Alberta was 5.0 (2000), 5.7 (2001), and 3.8 (2002) per 100,000. The two main metropolitan regions (Edmonton and Calgary) had the majority of iGAS disease cases (305 cases), producing incidence rates of 4.8 (Edmonton) and 6.9 (Calgary) in 2000, 6.9 (Edmonton) and 6.6 (Calgary) in 2001, and 4.1 (Edmonton) and 3.9 (Calgary) in 2002, as well as deaths attributable to GAS (31 deaths). The three most prevalent M types were M1 (71 cases), M3 (52 cases), and MPT2967 (44 cases). With respect to age, the highest incidence rates occurred in those less than 1 year old (11.7 per 100,000) and those 65 years or older (11.5 per 100,000). Varicella virus infection preceded iGAS disease in 25% of children 8 years of age and under. A seasonal association was observed during the 3 years studied, with the highest number of cases occurring in the winter months and the lowest occurring during the summer months. The data for years 2000 and 2001 show that the metropolitan regions of Alberta experienced some of the highest incidence rates reported in North America in the past decade.
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Affiliation(s)
- Gregory J Tyrrell
- The Department of Laboratory Medicine and Pathology, The University of Alberta, Edmonton, Alberta, Canada T6G 2R7.
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Ekelund K, Skinhøj P, Madsen J, Konradsen HB. Reemergence of emm1 and a changed superantigen profile for group A streptococci causing invasive infections: results from a nationwide study. J Clin Microbiol 2005; 43:1789-96. [PMID: 15815000 PMCID: PMC1081333 DOI: 10.1128/jcm.43.4.1789-1796.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Between 1999 and 2002, 496 invasive group A streptococcal (GAS) isolates from clinical microbiological departments in Denmark and subsequently 487 (98%) questionnaires from the clinicians treating the patients were received as part of a national surveillance. emm types and streptococcal superantigen (SAg) genes were determined. The incidence of invasive GAS infections was on average 2.3 per 100,000 per year. Bacteremia with no focal symptoms (27%) was together with erysipelas (20%) the most prevalent clinical diagnoses. Streptococcal toxic shock syndrome occurred in 10% of patients, of which 56% died. The overall case fatality rate within 30 days was 23%. In total, 47 different emm types were identified, of which emm1, emm3, emm4, emm12, emm28, and emm89 were identified in 72% of the 493 available isolates. During the 4-year period the presence of emm1 increased from 16% in 1999 to 40% in 2002. Concurrently, the presence of emm3 decreased from 23% in 1999 to 2% in 2002. The emm1 isolates predominantly carried speA, although the frequency decreased from 94% in 1999 to 71% in 2002, whereas the emm1-specific prevalence of speC increased from 25 to 53%. In a historical perspective, this could be interpreted as a reemergence of emm1 and could indicate a possible introduction of a new emm1 subclone. However, this reemergence did not result in any significant changes in the clinical manifestations during the study period. Our results show the complexity of invasive GAS infections, with time-dependent variations in the incidence and distribution of emm and SAg genes, which emphasizes the need for continuous epidemiological and molecular investigations.
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Affiliation(s)
- Kim Ekelund
- Streptococcus Unit, Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S., Denmark.
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