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Mårli MT, Oppegaard O, Porcellato D, Straume D, Kjos M. Genetic modification of Streptococcus dysgalactiae by natural transformation. mSphere 2024:e0021424. [PMID: 38904369 DOI: 10.1128/msphere.00214-24] [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: 03/18/2024] [Accepted: 05/13/2024] [Indexed: 06/22/2024] Open
Abstract
Streptococcus dysgalactiae is an emerging human and animal pathogen. Functional studies of genes involved in virulence of S. dysgalactiae and other pyogenic group streptococci are often hampered by limited genetic tractability. It is known that pyogenic streptococci carry genes required for competence for natural transformation; however, in contrast to other streptococcal subgroups, there is limited evidence for gene transfer by natural transformation in these bacteria. In this study, we systematically assessed the genomes of 179 S. dysgalactiae strains of both human and animal origins (subsp. equisimilis and dysgalactiae, respectively) for the presence of genes required for natural transformation. While a considerable fraction of the strains contained inactive genes, the majority (64.2%) of the strains had an intact gene set. In selected strains, we examined the dynamics of competence activation after addition of competence-inducing pheromones using transcriptional reporter assays and exploratory RNA-seq. Based on these findings, we were able to establish a protocol allowing us to utilize natural transformation to construct deletion mutants by allelic exchange in several S. dysgalactiae strains of both subspecies. As part of the work, we deleted putative lactose utilization genes to study their role in growth on lactose. The data presented here provide new knowledge on the potential of horizonal gene transfer by natural transformation in S. dysgalactiae and, importantly, demonstrates the possibility to exploit natural transformation for genetic engineering in these bacteria. IMPORTANCE Numerous Streptococcus spp. exchange genes horizontally through natural transformation, which also facilitates efficient genetic engineering in these organisms. However, for the pyogenic group of streptococci, including the emerging pathogen Streptococcus dysgalactiae, there is limited experimental evidence for natural transformation. In this study, we demonstrate that natural transformation in vitro indeed is possible in S. dysgalactiae strains under optimal conditions. We utilized this method to perform gene deletion through allelic exchange in several strains, thereby paving the way for more efficient gene engineering methods in pyogenic streptococci.
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Affiliation(s)
- Marita Torrissen Mårli
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Oddvar Oppegaard
- Haukeland University Hospital, University of Bergen, Bergen, Norway
| | - Davide Porcellato
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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Xie O, Davies MR, Tong SYC. Streptococcus dysgalactiae subsp. equisimilis infection and its intersection with Streptococcus pyogenes. Clin Microbiol Rev 2024:e0017523. [PMID: 38856686 DOI: 10.1128/cmr.00175-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
SUMMARYStreptococcus dysgalactiae subsp. equisimilis (SDSE) is an increasingly recognized cause of disease in humans. Disease manifestations range from non-invasive superficial skin and soft tissue infections to life-threatening streptococcal toxic shock syndrome and necrotizing fasciitis. Invasive disease is usually associated with co-morbidities, immunosuppression, and advancing age. The crude incidence of invasive disease approaches that of the closely related pathogen, Streptococcus pyogenes. Genomic epidemiology using whole-genome sequencing has revealed important insights into global SDSE population dynamics including emerging lineages and spread of anti-microbial resistance. It has also complemented observations of overlapping pathobiology between SDSE and S. pyogenes, including shared virulence factors and mobile gene content, potentially underlying shared pathogen phenotypes. This review provides an overview of the clinical and genomic epidemiology, disease manifestations, treatment, and virulence determinants of human infections with SDSE with a particular focus on its overlap with S. pyogenes. In doing so, we highlight the importance of understanding the overlap of SDSE and S. pyogenes to inform surveillance and disease control strategies.
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Affiliation(s)
- Ouli Xie
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Monash Infectious Diseases, Monash Health, Melbourne, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Steven Y C Tong
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Victorian Infectious Disease Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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Xie O, Morris JM, Hayes AJ, Towers RJ, Jespersen MG, Lees JA, Ben Zakour NL, Berking O, Baines SL, Carter GP, Tonkin-Hill G, Schrieber L, McIntyre L, Lacey JA, James TB, Sriprakash KS, Beatson SA, Hasegawa T, Giffard P, Steer AC, Batzloff MR, Beall BW, Pinho MD, Ramirez M, Bessen DE, Dougan G, Bentley SD, Walker MJ, Currie BJ, Tong SYC, McMillan DJ, Davies MR. Inter-species gene flow drives ongoing evolution of Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis. Nat Commun 2024; 15:2286. [PMID: 38480728 PMCID: PMC10937727 DOI: 10.1038/s41467-024-46530-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/28/2024] [Indexed: 03/17/2024] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging cause of human infection with invasive disease incidence and clinical manifestations comparable to the closely related species, Streptococcus pyogenes. Through systematic genomic analyses of 501 disseminated SDSE strains, we demonstrate extensive overlap between the genomes of SDSE and S. pyogenes. More than 75% of core genes are shared between the two species with one third demonstrating evidence of cross-species recombination. Twenty-five percent of mobile genetic element (MGE) clusters and 16 of 55 SDSE MGE insertion regions were shared across species. Assessing potential cross-protection from leading S. pyogenes vaccine candidates on SDSE, 12/34 preclinical vaccine antigen genes were shown to be present in >99% of isolates of both species. Relevant to possible vaccine evasion, six vaccine candidate genes demonstrated evidence of inter-species recombination. These findings demonstrate previously unappreciated levels of genomic overlap between these closely related pathogens with implications for streptococcal pathobiology, disease surveillance and prevention.
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Affiliation(s)
- Ouli Xie
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Monash Infectious Diseases, Monash Health, Melbourne, Australia
| | - Jacqueline M Morris
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Andrew J Hayes
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Rebecca J Towers
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Magnus G Jespersen
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - John A Lees
- European Molecular Biology Laboratory, European Bioinformatics Institute EMBL-EBI, Hinxton, Cambridgeshire, UK
| | - Nouri L Ben Zakour
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Olga Berking
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Sarah L Baines
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Glen P Carter
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | | | - Layla Schrieber
- Faculty of Veterinary Science, The University of Sydney, Sydney, Australia
| | - Liam McIntyre
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Jake A Lacey
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Taylah B James
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Kadaba S Sriprakash
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- School of Science & Technology, University of New England, Armidale, Australia
| | - Scott A Beatson
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Tadao Hasegawa
- Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Phil Giffard
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Andrew C Steer
- Tropical Diseases, Murdoch Children's Research Institute, Parkville, Australia
| | - Michael R Batzloff
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Bernard W Beall
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Marcos D Pinho
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Mario Ramirez
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Debra E Bessen
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
| | - Gordon Dougan
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, Cambridgeshire, UK
| | - Stephen D Bentley
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, Cambridgeshire, UK
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Bart J Currie
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Steven Y C Tong
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Victorian Infectious Disease Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - David J McMillan
- School of Science, Technology and Engineering, and Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
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Kozakai M, Matsumoto M, Takakura A, Furuta RA, Matsubayashi K, Goto N, Satake M. Two cases of Streptococcus dysgalactiae subspecies equisimilis infection transmitted through transfusion of platelet concentrate derived from separate blood donations by the same donor. Vox Sang 2023. [PMID: 37191237 DOI: 10.1111/vox.13472] [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: 02/17/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Transfusion-transmitted bacterial infections (TTBIs) in Japan have been largely prevented due to a short shelf life of 3.5 days after blood collection for platelet concentrate (PC) and washed PCs (WPCs; PC in which 95% plasma is replaced by platelet additive solution). CASE PRESENTATION Case 1: In January 2018, a woman in her 50s with aplastic anaemia who received WPC transfusion and developed a fever the next day and Streptococcus dysgalactiae subspecies equisimilis (SDSE) was detected in the residual WPC. Case 2: In May 2018, a man in his 60s with a haematologic malignancy who received PC transfusion and developed chills during the transfusion. SDSE was detected in the patient's blood and residual PC. The contaminated platelet products were both manufactured from blood donated by the same donor. The multi-locus sequencing typing revealed that SDSE detected in case 1 was identical to that from case 2; however, whole blood subsequently obtained from the donor was culture negative. CONCLUSION WPC and PC produced from two blood donated 106 days apart by the same donor were contaminated with SDSE of the same strain and both caused TTBIs. Safety measures should be considered regarding blood collection from a donor with a history of bacterial contamination.
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Affiliation(s)
- Moe Kozakai
- Japanese Red Cross Society, Central Blood Institute, Tokyo, Japan
| | - Mami Matsumoto
- Japanese Red Cross Society, Central Blood Institute, Tokyo, Japan
| | - Akiko Takakura
- Japanese Red Cross Society, Central Blood Institute, Tokyo, Japan
| | - Rika A Furuta
- Japanese Red Cross Society, Central Blood Institute, Tokyo, Japan
| | | | - Naoko Goto
- Japanese Red Cross Society, Blood Service Headquarters, Tokyo, Japan
| | - Masahiro Satake
- Japanese Red Cross Society, Blood Service Headquarters, Tokyo, Japan
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Kaci A, Jonassen CM, Skrede S, Sivertsen A, Steinbakk M, Oppegaard O. Genomic epidemiology of Streptococcus dysgalactiae subsp. equisimilis strains causing invasive disease in Norway during 2018. Front Microbiol 2023; 14:1171913. [PMID: 37485526 PMCID: PMC10361778 DOI: 10.3389/fmicb.2023.1171913] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/31/2023] [Indexed: 07/25/2023] Open
Abstract
Background Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging global pathogen, yet the epidemiology and population genetics of SDSE species have not been extensively characterized. Methods We carried out whole genome sequencing to characterize 274 SDSE isolates causing bloodstream infections obtained through national surveillance program in 2018. We conducted multilocus sequence typing (MLST), emm-typing, core genome phylogeny, as well as investigated key features associated with virulence. Moreover, comparison to SDSE from other geographic regions were performed in order to gain more insight in the evolutionary dynamics in SDSE. Results The phylogenetic analysis indicated a substantial diversity of emm-types and sequence types (STs). Briefly, 17 emm-types and 58 STs were identified that formed 10 clonal complexes (CCs). The predominant ST-types were ST20 (20%), ST17 (17%), and ST29 (11%). While CC17 and CC29 clades showed a substantial heterogeneity with well-separated emm-associated subclades, the CC20 clade harboring the stG62647 emm-type was more homogenous and the most prevalent in the present study. Moreover, we observed notable differences in the distribution of clades within Norway, as well as several disseminated CCs and also distinct geographic variations when compared to data from other countries. We also revealed extensive intra-species recombination events involving surface exposed virulence factors, including the emm gene important for phylogenetic profiling. Conclusion Recombination events involving the emm as well as other virulence genes in SDSE, are important mechanisms in shaping the genetic variability in the SDSE population, potentially offering selective advantages to certain lineages. The enhanced phylogenetic resolution offered by whole genome sequencing is necessary to identify and delimitate outbreaks, monitor and properly characterize emerging strains, as well as elucidate bacterial population dynamics.
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Affiliation(s)
- Alba Kaci
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
| | - Christine M. Jonassen
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
- Department of Virology, Norwegian Institute of Public Health, Oslo, Norway
| | - Steinar Skrede
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Audun Sivertsen
- Department of Microbiology, Haukeland University Hospital, Bergen, Norway
| | | | - Martin Steinbakk
- Center for Laboratory Medicine, Østfold Hospital Trust, Grålum, Norway
| | - Oddvar Oppegaard
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
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Beres SB, Olsen RJ, Long SW, Eraso JM, Boukthir S, Faili A, Kayal S, Musser JM. Analysis of the Genomics and Mouse Virulence of an Emergent Clone of Streptococcus dysgalactiae Subspecies equisimilis. Microbiol Spectr 2023; 11:e0455022. [PMID: 36971562 PMCID: PMC10100674 DOI: 10.1128/spectrum.04550-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/04/2023] [Indexed: 03/29/2023] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis is a bacterial pathogen that is increasingly recognized as a cause of severe human infections. Much less is known about the genomics and infection pathogenesis of S. dysgalactiae subsp. equisimilis strains compared to the closely related bacterium Streptococcus pyogenes. To address these knowledge deficits, we sequenced to closure the genomes of seven S. dysgalactiae subsp. equisimilis human isolates, including six that were emm type stG62647. Recently, for unknown reasons, strains of this emm type have emerged and caused an increasing number of severe human infections in several countries. The genomes of these seven strains vary between 2.15 and 2.21 Mbp. The core chromosomes of these six S. dysgalactiae subsp. equisimilis stG62647 strains are closely related, differing on average by only 495 single-nucleotide polymorphisms, consistent with a recent descent from a common progenitor. The largest source of genetic diversity among these seven isolates is differences in putative mobile genetic elements, both chromosomal and extrachromosomal. Consistent with the epidemiological observations of increased frequency and severity of infections, both stG62647 strains studied were significantly more virulent than a strain of emm type stC74a in a mouse model of necrotizing myositis, as assessed by bacterial CFU burden, lesion size, and survival curves. Taken together, our genomic and pathogenesis data show the strains of emm type stG62647 we studied are closely genetically related and have enhanced virulence in a mouse model of severe invasive disease. Our findings underscore the need for expanded study of the genomics and molecular pathogenesis of S. dysgalactiae subsp. equisimilis strains causing human infections. IMPORTANCE Our studies addressed a critical knowledge gap in understanding the genomics and virulence of the bacterial pathogen Streptococcus dysgalactiae subsp. equisimilis. S. dysgalactiae subsp. equisimilis strains are responsible for a recent increase in severe human infections in some countries. We determined that certain S. dysgalactiae subsp. equisimilis strains are genetically descended from a common ancestor and that these strains can cause severe infections in a mouse model of necrotizing myositis. Our findings highlight the need for expanded studies on the genomics and pathogenic mechanisms of this understudied subspecies of the Streptococcus family.
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Affiliation(s)
- Stephen B. Beres
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
| | - Randall J. Olsen
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - S. Wesley Long
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - Jesus M. Eraso
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Sarrah Boukthir
- CHU de Rennes, Service de Bacteriologie-Hygiène Hospitalière, Rennes, France
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Médecine, Rennes, France
| | - Ahmad Faili
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Pharmacie, Rennes, France
- Chemistry, Oncogenesis, Stress, and Signaling, INSERM 1242, Rennes, France
| | - Samer Kayal
- CHU de Rennes, Service de Bacteriologie-Hygiène Hospitalière, Rennes, France
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Médecine, Rennes, France
- Chemistry, Oncogenesis, Stress, and Signaling, INSERM 1242, Rennes, France
| | - James M. Musser
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
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Senneby E, Hallström B, Rasmussen M. Genetic relatedness of Streptococcus dysgalactiae isolates causing recurrent bacteraemia. J Med Microbiol 2021; 70. [PMID: 33616518 DOI: 10.1099/jmm.0.001330] [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: 11/18/2022] Open
Abstract
Introduction. Streptococcus dysgalactiae subspecies equisimilis (SDSE) is becoming increasingly recognized as an important human pathogen. Recurrent bacteremia with SDSE has been described previously.Aim. The aims of the study were to establish the genetic relatedness of SDSE isolates with emm-type stG643 that had caused recurrent bacteraemia in three patients and to search for signs of horizontal gene transfer of the emm gene in a collection of SDSE stG643 genomes.Hypothesis. Recurring SDSE bacteremia is caused by the same clone in one patient.Methodology. Whole genome sequencing of 22 clinical SDSE stG643 isolates was performed, including three paired blood culture isolates and sixteen isolates from various sites. All assemblies were aligned to a reference assembly and SNPs were extracted. A total of 53 SDSE genomes were downloaded from GenBank. Two phylogenetic trees, including all 75 SDSE isolates, were created. One tree was based on the emm gene only and one tree was based on all variable positions in the genomes.Results. The genomes from the three pairs of SDSE isolates showed high sequence similarity (1-17 SNPs difference between the pairs), whereas the median SNP difference between the 22 isolates in our collection was 1694 (range 1-11257). The paired isolates were retrieved with 7-53 months between episodes. The 22 SDSE isolates from our collection formed a cluster in the phylogenetic tree based on the emm gene, while they were more scattered in the tree based on all variable positions.Conclusions. Our results show that the paired isolates were of the same clonal origin, which in turn supports carriage between bacteraemia episodes. The phylogenetic analysis indicates that horizontal gene transfer of the emm-gene between some of the SDSE isolates has occurred.
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Affiliation(s)
- Erik Senneby
- Infection Medicine, Department of clinical sciences, Lund University, Lund, Sweden
| | - Björn Hallström
- Centre for Translational Genomics, Division of Clinical Genetics, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Infection Medicine, Department of clinical sciences, Lund University, Lund, Sweden
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Eibl C, Baumgartner M, Urbantke V, Sigmund M, Lichtmannsperger K, Wittek T, Spergser J. An Outbreak of Subclinical Mastitis in a Dairy Herd Caused by a Novel Streptococcus canis Sequence Type (ST55). Animals (Basel) 2021; 11:ani11020550. [PMID: 33672442 PMCID: PMC7923261 DOI: 10.3390/ani11020550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 02/13/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Although Streptococcus (S). canis is mainly isolated from carnivores, intramammary infection in dairy cows caused by this bacterium have been reported. Cats and dogs with access to the barn have been considered as the main source of these infections. Here, we report subclinical mastitis and substantially increased bulk milk somatic cell counts in a dairy herd. During a herd visit, management and hygiene practices were evaluated and data from the milk quality control program were retrieved. Furthermore, quarter milk samples, mucosal swabs from farm cats and a dog, and swabs from the milking unit were aseptically collected. The samples were examined bacteriologically, and S. canis was identified using conventional phenotypic methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Genetic relationships between S. canis isolates were determined by multilocus sequence typing, revealing that all S. canis isolates shared the same sequence type, presenting a new combination of alleles for which a new number (ST55) was assigned. As the most likely source of intramammary infection, a farmyard cat was identified. The concurrent treatment of all positive cows and the improvement of management (no further access of carnivores to the barn) lead to positive results, including a decreased somatic cell count. Abstract The present case report provides data on the phenotypic and genotypic properties of S. canis isolated from nine dairy cows with subclinical mastitis (SCC greater than 200,000 cells/mL in the quarter milk sample, no clinical signs) and from a cat living in the barn and reports the eradication of the pathogen from the herd with an automatic milking system. The isolates were identified using conventional bacteriology, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and genetic relationships were investigated by multilocus sequence typing (MLST). Udder health management and hygiene instructions comprised the removal of the carnivores from the barn, strict monitoring of milking hygiene and techniques to avoid new infections via the milking robot, with simultaneous therapy for all infected cows. Phenotypic and genotypic properties of all isolates were identical. MLST revealed a unique sequence type (ST55) and a farmyard cat was identified as the most likely source of the S. canis infection in cows. The simultaneous treatment of all infected cows and management and hygiene improvements lead to a decreased SCC within four weeks.
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Affiliation(s)
- Cassandra Eibl
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
- Correspondence: ; Tel.: +43-1-25077-5203
| | - Martina Baumgartner
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
| | - Verena Urbantke
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
| | - Michael Sigmund
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
| | - Katharina Lichtmannsperger
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
| | - Thomas Wittek
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.B.); (V.U.); (M.S.); (K.L.); (T.W.)
| | - Joachim Spergser
- Institute of Microbiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria;
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Oh SI, Kim JW, Kim J, So B, Kim B, Kim HY. Molecular subtyping and antimicrobial susceptibility of Streptococcus dysgalactiae subspecies equisimilis isolates from clinically diseased pigs. J Vet Sci 2020; 21:e57. [PMID: 32735095 PMCID: PMC7402932 DOI: 10.4142/jvs.2020.21.e57] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/13/2020] [Accepted: 04/16/2020] [Indexed: 11/30/2022] Open
Abstract
Background Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. Objectives This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. Methods A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. Results Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. Conclusion This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.
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Affiliation(s)
- Sang Ik Oh
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea.,College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Jong Wan Kim
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea
| | - Jongho Kim
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea
| | - Byungjae So
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea
| | - Bumseok Kim
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Ha Young Kim
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea.
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10
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Santos VL, Silva LG, Martini CL, Anjos IHV, Maia MM, Genteluci GL, Sant'Anna V, Ferreira AMA, Couceiro JNSS, Figueiredo AMS, Ferreira-Carvalho BT. Low lineage diversity and increased virulence of group C Streptococcus dysgalactiae subsp. equisimilis. J Med Microbiol 2020; 69:576-586. [PMID: 32125264 DOI: 10.1099/jmm.0.001165] [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: 11/18/2022] Open
Abstract
Introduction. In some species, the population structure of pathogenic bacteria is clonal. However, the mechanisms that determine the predominance and persistence of specific bacterial lineages of group C Streptococcus remain poorly understood. In Brazil, a previous study revealed the predominance of two main lineages of Streptococcus dysgalactiae subsp. equisimilis (SDSE).Aim. The aim of this study was to assess the virulence and fitness advantages that might explain the predominance of these SDSE lineages for a long period of time.Methodology. emm typing was determined by DNA sequencing. Adhesion and invasion tests were performed using human bronchial epithelial cells (16HBE14o-). Biofilm formation was tested on glass surfaces and the presence of virulence genes was assessed by PCR. Additionally, virulence was studied using Caenorhabditis elegans models and competitive fitness was analysed in murine models.Results. The predominant lineages A and B were mostly typed as emm stC839 and stC6979, respectively. Notably, these lineages exhibited a superior ability to adhere and invade airway cells. Furthermore, the dominant lineages were more prone to induce aversive olfactory learning and more likely to kill C. elegans. In the competitive fitness assays, they also showed increased adaptability. Consistent with the increased virulence observed in the ex vivo and in vivo models, the predominant lineages A and B showed a higher number of virulence-associated genes and a superior ability to accumulate biofilm.Conclusion. These results suggest strongly that this predominance did not occur randomly but rather was due to adaptive mechanisms that culminated in increased colonization and other bacterial properties that might confer increased bacteria-host adaptability to cause disease.
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Affiliation(s)
- Victor Lima Santos
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Ligia Guedes Silva
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Caroline Lopes Martini
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Isis Hazelman V Anjos
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Mariana Masello Maia
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Gabrielle L Genteluci
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Viviane Sant'Anna
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Ana Maria A Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - José Nelson S S Couceiro
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
| | - Agnes Marie Sá Figueiredo
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, Brazil
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11
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Enache AE, Mitchell C, Kafarnik C, Waller AS. Streptococcus canis multilocus sequence typing in a case series of dogs with ulcerative keratitis. Vet Ophthalmol 2019; 23:252-258. [PMID: 31566875 DOI: 10.1111/vop.12714] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/04/2019] [Accepted: 09/07/2019] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To determine whether four isolates of Streptococcus canis (S canis) recovered from dogs diagnosed with ulcerative keratitis at the Animal Health Trust (AHT) were genetically related to other ocular isolates that are registered in the online database. ANIMAL STUDIED Four S canis corneal isolates. PROCEDURES Clinical and laboratory records between 2016 and 2017 were searched for dogs with ulcerative keratitis for which microbiology analysis was consistent with the growth of S canis. Genomic DNA was extracted for sequencing (Illumina MiSeq), and multilocus sequence types (STs) were determined using MLST 1.8 relative to the 44 sequence types of S canis available. A neighbor-joining tree was constructed in MEGA v4.0. A two-sided Fisher's exact test was used to determine any associations between the isolated strains and ocular infections of dogs. RESULTS Four strains were isolated from pugs (cases 1-4) with ulcerative keratitis. Genome sequencing identified ST-27 (case 1), ST-9 (case 3), and ST-13 (cases 2 and 4). STs 13 and 27 are members of Clonal Complex (CC)-13. Analysis of the multilocus sequence typing database revealed that CC-13 strains accounted for six of the twelve isolates recovered from the eye exudates of dogs (P = .0078). CONCLUSIONS There is early evidence that the CC-13 group of S canis is associated with ocular infections in dogs. We provide draft genome sequences toward the future identification of virulence mechanisms associated with streptococcal keratitis in dogs.
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12
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Kakuta R, Shimizu T, Goto H, Endo S, Kanamori H, Ohta N, Nakano R, Yano H, Katori Y, Kaku M. Abdominal Aortic Graft Infection Caused by stG485.0, ST29 Streptococcus dysgalactiae subsp. equisimilis. Jpn J Infect Dis 2019; 73:65-67. [PMID: 31564693 DOI: 10.7883/yoken.jjid.2019.171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In recent years, the prevalence of invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) infections has increased gradually throughout the world, including Japan. Here, we report the case of an abdominal aortic graft infection caused by stG485.0, ST29 SDSE in an elderly patient with diabetes. The patient was an 86-year-old man who had undergone surgery 10 years ago for treating a non-infected abdominal aortic aneurysm using a bifurcated graft. He was referred to our hospital after being suspected of having an abdominal aortic graft infection based on computed tomography (CT) scans. He underwent surgery to drain the pus that had accumulated between the aneurysm and graft. Although blood cultures were negative, the surgical specimen culture was positive for a β-hemolytic group G streptococci, which was subsequently identified as SDSE using 16S ribosomal RNA sequencing. Genetic relationships deduced from emm and multilocus sequence typing revealed the isolate to be types stG485.0 and ST29, respectively. Although aortic aneurysm graft infection has a poor prognosis, we successfully rescued the patient through prompt surgery and identification of the responsible pathogen. This case indicates that attention must be paid toward possible SDSE infections in the field of vascular surgery.
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Affiliation(s)
- Risako Kakuta
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Hospital
| | - Takuya Shimizu
- Division of Cardiovascular Surgery, Tohoku Medical and Pharmaceutical University
| | - Hitoshi Goto
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine
| | - Shiro Endo
- Intelligent Network for Infection Control, Donated Fund Laboratory, Tohoku University
| | - Hajime Kanamori
- Division of Vascular Surgery, Department of Surgery, Tohoku University Hospital
| | - Nobuo Ohta
- Division of Otolaryngology, Tohoku Medical and Pharmaceutical University
| | - Ryuichi Nakano
- Department of Microbiology and Infectious Diseases, Nara Medical University
| | - Hisakazu Yano
- Department of Microbiology and Infectious Diseases, Nara Medical University
| | - Yukio Katori
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Hospital
| | - Mitsuo Kaku
- Division of Vascular Surgery, Department of Surgery, Tohoku University Hospital.,Division of Infectious Diseases and Infection Control, Faculty of Medicine, Tohoku Medical and Pharmaceutical University
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13
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Chochua S, Rivers J, Mathis S, Li Z, Velusamy S, McGee L, Van Beneden C, Li Y, Metcalf BJ, Beall B. Emergent Invasive Group A Streptococcus dysgalactiae subsp. equisimilis, United States, 2015-2018. Emerg Infect Dis 2019; 25:1543-1547. [PMID: 31158071 PMCID: PMC6649341 DOI: 10.3201/eid2508.181758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The term group A Streptococcus is considered synonymous for the species Streptococcus pyogenes. We describe an emergent invasive S. dysgalactiae subspecies equisimilis lineage that obtained the group A antigen through a single ancestral recombination event between a group C S. dysgalactiae subsp. equisimilis strain and a group A S. pyogenes strain.
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14
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Infections Caused by Group C and G Streptococcus ( Streptococcus dysgalactiae subsp. equisimilis and Others): Epidemiological and Clinical Aspects. Microbiol Spectr 2019; 7. [PMID: 30977463 DOI: 10.1128/microbiolspec.gpp3-0016-2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Streptococci carrying serogroup C and G antigens, and in particular, Streptococcus dysgalactiae subsp. equisimilis (SDSE), are emerging human pathogens that are increasingly isolated from patients with a myriad of infections that range from mundane to life-threatening. SDSE is microbiologically similar to Streptococcus pyogenes. These streptococci frequently cause infections of the throat and skin and soft tissues. Moreover, they may invade the bloodstream and disseminate widely to many deep tissue sites, including the endocardium. Life-threatening invasive infections due to SDSE, including the streptococcal toxic shock syndrome, occur most frequently in patients with severe underlying medical diseases. Treatment with penicillin is adequate under most circumstances, but treatment failure occurs. SDSE may also be resistant to other antibiotic classes including tetracyclines, macrolides, and clindamycin. Most human infections caused by groups C and G streptococci are transmitted from person to person, but infections due to Streptococcus equi subsp. zooepidemicus (and, rarely, to S. equi subsp. equi) are zoonoses. Transmission of these latter species occurs by animal contact or by contamination of food products and has been associated with the development of poststreptococcal glomerulonephritis. Members of the Streptococcus anginosus group, usually classified with the viridans group of streptococci, are associated with a variety of pyogenic infections.
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15
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Nerlich A, Lapschies AM, Kohler TP, Cornax I, Eichhorn I, Goldmann O, Krienke P, Bergmann S, Nizet V, Hammerschmidt S, Rohde M, Fulde M. Homophilic protein interactions facilitate bacterial aggregation and IgG-dependent complex formation by the Streptococcus canis M protein SCM. Virulence 2019; 10:194-206. [PMID: 30829556 PMCID: PMC6527014 DOI: 10.1080/21505594.2019.1589362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Streptococcus canis is a zoonotic agent that causes serious invasive diseases in domestic animals and humans, but knowledge about its pathogenic potential and underlying virulence mechanisms is limited. Here, we report on the ability of certain S. canis isolates to form large bacterial aggregates when grown in liquid broth. Bacterial aggregation was attributed to the presence and the self-binding activity of SCM, the M protein of S. canis, as evaluated by bacterial sedimentation assays, immunofluorescence- and electron microscopic approaches. Using a variety of truncated recombinant SCM fragments, we demonstrated that homophilic SCM interactions occur via the N-terminal, but not the C-terminal part, of the mature M protein. Interestingly, when incubated in human plasma, SCM forms soluble protein complexes comprising its known ligands, immunoglobulin G (IgG) and plasminogen (Plg). Co-incubation studies with purified host proteins revealed that SCM-mediated complex formation is based on the interaction of SCM with itself and with IgG, but not with Plg or fibrinogen (Fbg), well-established constituents of M protein-mediated protein complexes in human-associated streptococci. Notably, these soluble, SCM-mediated plasma complexes harbored complement factor C1q, which can induce complement breakdown in the periphery and therefore represent another immune evasion mechanism of SCM.
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Affiliation(s)
- Andreas Nerlich
- a Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine , Charité Universitätsmedizin Berlin , Berlin , Germany.,b Department of Medical Microbiology , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Antje-Maria Lapschies
- c Institute of Microbiology and Epizootics, Centre of Infection Medicine , Freie Universität Berlin , Berlin , Germany
| | - Thomas P Kohler
- d Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes , University of Greifswald , Greifswald , Germany
| | - Ingrid Cornax
- e Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences , UC San Diego , La Jolla , CA , USA
| | - Inga Eichhorn
- c Institute of Microbiology and Epizootics, Centre of Infection Medicine , Freie Universität Berlin , Berlin , Germany
| | - Oliver Goldmann
- f Infection Immunology Group, Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Petra Krienke
- c Institute of Microbiology and Epizootics, Centre of Infection Medicine , Freie Universität Berlin , Berlin , Germany
| | - Simone Bergmann
- b Department of Medical Microbiology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,g Department of Infection Biology, Institute of Microbiology , Technische Universität Braunschweig , Braunschweig , Germany
| | - Victor Nizet
- e Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences , UC San Diego , La Jolla , CA , USA
| | - Sven Hammerschmidt
- d Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes , University of Greifswald , Greifswald , Germany
| | - Manfred Rohde
- b Department of Medical Microbiology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,h Central Facility for Microscopy , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Marcus Fulde
- b Department of Medical Microbiology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,c Institute of Microbiology and Epizootics, Centre of Infection Medicine , Freie Universität Berlin , Berlin , Germany
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16
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Pinho MD, Foster G, Pomba C, Machado MP, Baily JL, Kuiken T, Melo-Cristino J, Ramirez M. Streptococcus canis Are a Single Population Infecting Multiple Animal Hosts Despite the Diversity of the Universally Present M-Like Protein SCM. Front Microbiol 2019; 10:631. [PMID: 30984150 PMCID: PMC6450190 DOI: 10.3389/fmicb.2019.00631] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/13/2019] [Indexed: 11/13/2022] Open
Abstract
Streptococcus canis is an animal pathogen which occasionally causes infections in humans. The S. canis M-like protein (SCM) encoded by the scm gene, is its best characterized virulence factor but previous studies suggested it could be absent in a substantial fraction of isolates. We studied the distribution and variability of the scm gene in 188 S. canis isolates recovered from companion animals (n = 152), wild animal species (n = 20), and humans (n = 14). Multilocus sequence typing, including the first characterization of wildlife isolates, showed that the same lineages are present in all animal hosts, raising the possibility of extensive circulation between species. Whole-genome analysis revealed that emm-like genes found previously in S. canis correspond to divergent scm genes, indicating that what was previously believed to correspond to two genes is in fact the same scm locus. We designed primers allowing for the first time the successful amplification of the scm gene in all isolates. Analysis of the scm sequences identified 12 distinct types, which could be divided into two clusters: group I (76%, n = 142) and group II (24%, n = 46) sharing little sequence similarity. The predicted group I SCM showed extensive similarity with each other outside of the N-terminal hypervariable region and a conserved IgG binding domain. This domain was absent from group II SCM variants found in isolates previously thought to lack the scm gene, which also showed greater amino acid variability. Further studies are necessary to elucidate the possible host interacting partners of the group II SCM variants and their role in virulence.
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Affiliation(s)
- Marcos D Pinho
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | - Constança Pomba
- Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel P Machado
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Johanna L Baily
- Moredun Research Institute, Pentlands Science Park, Edinburgh, United Kingdom
| | - Thijs Kuiken
- Department of Viroscience, Erasmus Medical Center, Rotterdam, Netherlands
| | - José Melo-Cristino
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Mário Ramirez
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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17
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Abstract
The clinico-epidemiological features of diseases caused by group A streptococci (GAS) is presented through the lens of the ecology, population genetics, and evolution of the organism. The serological targets of three typing schemes (M, T, SOF) are themselves GAS cell surface proteins that have a myriad of virulence functions and a diverse array of structural forms. Horizontal gene transfer expands the GAS antigenic cell surface repertoire by generating numerous combinations of M, T, and SOF antigens. However, horizontal gene transfer of the serotype determinant genes is not unconstrained, and therein lies a genetic organization that may signify adaptations to a narrow ecological niche, such as the primary tissue reservoirs of the human host. Adaptations may be further shaped by selection pressures such as herd immunity. Understanding the molecular evolution of GAS on multiple levels-short, intermediate, and long term-sheds insight on mechanisms of host-pathogen interactions, the emergence and spread of new clones, rational vaccine design, and public health interventions.
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18
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Fukushima Y, Tsuyuki Y, Goto M, Yoshida H, Takahashi T. Species Identification of β-Hemolytic Streptococci from Diseased Companion Animals and Their Antimicrobial Resistance Data in Japan (2017). Jpn J Infect Dis 2018; 72:94-98. [PMID: 30381681 DOI: 10.7883/yoken.jjid.2018.231] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study aimed to identify the species and assess the antimicrobial resistance (AMR) of β-hemolytic streptococci isolated from companion animals in Japan. Strains were isolated from clinical specimens of 131 companion animals that exhibited symptoms in April-May 2017. We identified strains by 16S rRNA sequencing and assessed their antimicrobial susceptibility using the broth microdilution method. AMR genes erm(A)-erm(B)-mef(A) and tet(M)-tet(O)-tet(K)-tet(L)-tet(S) in all isolates were amplified by PCR. 16S rRNA sequencing identified β-hemolytic streptococcal species as Streptococcus canis (n = 117, 89.3%), S. agalactiae (n = 7), S. dysgalactiae subsp. equisimilis (n = 5), S. dysgalactiae subsp. dysgalactiae (n = 1), and S. equi subsp. zooepidemicus (n = 1). Overall AMR rates were 39.7% for minocycline, 19.8% for erythromycin, and 17.6% for clindamycin, with a minimum inhibitory concentration (MIC90) of > 4, > 2, and > 1 μg/mL, respectively. AMR genotyping showed the presence of single or mixed types: erm(B)-mef(A) and tet(M)-tet(O)-tet(L)-tet(S). There was a significant relationship between tetracycline-resistance genotypes and open pus/skin-derived specimens. These observations identify some unique features of β-hemolytic streptococcal isolates from companion animals in Japan, such as the dominant isolation of S. canis and resistance to tetracycline, macrolide, and lincosamide antibiotics, in terms of species identification and AMR properties.
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Affiliation(s)
- Yasuto Fukushima
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Kitasato Institute for Life Sciences, Kitasato University
| | - Yuzo Tsuyuki
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Kitasato Institute for Life Sciences, Kitasato University.,Division of Clinical Laboratory, Sanritsu Zelkova Veterinary Laboratory
| | - Mieko Goto
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Kitasato Institute for Life Sciences, Kitasato University
| | - Haruno Yoshida
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Kitasato Institute for Life Sciences, Kitasato University
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Kitasato Institute for Life Sciences, Kitasato University
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19
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Kim S, Byun JH, Park H, Lee J, Lee HS, Yoshida H, Shibayama A, Fujita T, Tsuyuki Y, Takahashi T. Molecular Epidemiological Features and Antibiotic Susceptibility Patterns of Streptococcus dysgalactiae subsp. equisimilis Isolates from Korea and Japan. Ann Lab Med 2018; 38:212-219. [PMID: 29401555 PMCID: PMC5820065 DOI: 10.3343/alm.2018.38.3.212] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/02/2017] [Accepted: 01/05/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The molecular characterization of Streptococcus dysgalactiae subsp. equisimilis (SDSE) has not yet been performed in Korea. This study aimed to find the differences or similarities in the clinical features, molecular epidemiological findings, and antimicrobial resistance patterns of SDSE from two countries (Korea and Japan). METHODS SDSE isolates were collected from Korea (N=69) from 2012-2016 and Japan (N=71) from 2014-2016. Clinical characteristics, emm genotypes, and sequence types (STs) were compared. Microdilution tests were performed using different antimicrobials, and their resistance determinants were screened. RESULTS Median ages were 69 years in Korea and 76 years in Japan. The most common underlying diseases were diabetes and malignancy. Blood-derived isolates comprised 36.2% and 50.7% of Korean and Japanese isolates, respectively; mortality was not different between the two groups (5.8% vs 9.9%, P=0.53). Among Korean isolates with 20 different combined ST-emm types, ST127-stG245 (N=16), ST128-stG485 (N=10), and ST138-stG652 (N=8) were prevalent. Among Japanese isolates with 29 different combined types, ST17-stG6792 (N=11), ST29-stG485 (N=7), and ST205-stG6792 (N=6) were prevalent. Resistance rates to erythromycin, clindamycin, and minocycline were 34.8%, 17.4%, and 30.4% in Korea and 28.2%, 14.1%, and 21.4% in Japan, respectively. CONCLUSIONS SDSE infections commonly occurred in elderly persons with underlying diseases. There was a significant difference in the distribution of ST-emm types between the two countries. Antimicrobial resistance rates were comparable with different frequencies of resistance determinants in each country.
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Affiliation(s)
- Sunjoo Kim
- Department of Laboratory Medicine, Gyeongsang National University College of Medicine, Jinju, Korea
| | - Jung Hyun Byun
- Department of Laboratory Medicine, Gyeongsang National University College of Medicine, Jinju, Korea
| | - Hyunwoong Park
- Department of Laboratory Medicine, Gyeongsang National University College of Medicine, Jinju, Korea
| | - Jaehyeon Lee
- Department of Laboratory Medicine, Chonbuk National University School of Medicine, Jeonju, Korea
| | - Hye Soo Lee
- Department of Laboratory Medicine, Chonbuk National University School of Medicine, Jeonju, Korea
| | - Haruno Yoshida
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan
| | - Akiyoshi Shibayama
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan
| | - Tomohiro Fujita
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan
| | - Yuzo Tsuyuki
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan.
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20
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Population and Whole Genome Sequence Based Characterization of Invasive Group A Streptococci Recovered in the United States during 2015. mBio 2017; 8:mBio.01422-17. [PMID: 28928212 PMCID: PMC5605940 DOI: 10.1128/mbio.01422-17] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Group A streptococci (GAS) are genetically diverse. Determination of strain features can reveal associations with disease and resistance and assist in vaccine formulation. We employed whole-genome sequence (WGS)-based characterization of 1,454 invasive GAS isolates recovered in 2015 by Active Bacterial Core Surveillance and performed conventional antimicrobial susceptibility testing. Predictions were made for genotype, GAS carbohydrate, antimicrobial resistance, surface proteins (M family, fibronectin binding, T, R28), secreted virulence proteins (Sda1, Sic, exotoxins), hyaluronate capsule, and an upregulated nga operon (encodes NADase and streptolysin O) promoter (Pnga3). Sixty-four M protein gene (emm) types were identified among 69 clonal complexes (CCs), including one CC of Streptococcus dysgalactiae subsp. equisimilis. emm types predicted the presence or absence of active sof determinants and were segregated into sof-positive or sof-negative genetic complexes. Only one “emm type switch” between strains was apparent. sof-negative strains showed a propensity to cause infections in the first quarter of the year, while sof+ strain infections were more likely in summer. Of 1,454 isolates, 808 (55.6%) were Pnga3 positive and 637 (78.9%) were accounted for by types emm1, emm89, and emm12. Theoretical coverage of a 30-valent M vaccine combined with an M-related protein (Mrp) vaccine encompassed 98% of the isolates. WGS data predicted that 15.3, 13.8, 12.7, and 0.6% of the isolates were nonsusceptible to tetracycline, erythromycin plus clindamycin, erythromycin, and fluoroquinolones, respectively, with only 19 discordant phenotypic results. Close phylogenetic clustering of emm59 isolates was consistent with recent regional emergence. This study revealed strain traits informative for GAS disease incidence tracking, outbreak detection, vaccine strategy, and antimicrobial therapy. The current population-based WGS data from GAS strains causing invasive disease in the United States provide insights important for prevention and control strategies. Strain distribution data support recently proposed multivalent M type-specific and conserved M-like protein vaccine formulations that could potentially protect against nearly all invasive U.S. strains. The three most prevalent clonal complexes share key polymorphisms in the nga operon encoding two secreted virulence factors (NADase and streptolysin O) that have been previously associated with high strain virulence and transmissibility. We find that Streptococcus pyogenes is phylogenetically subdivided into loosely defined multilocus sequence type-based clusters consisting of solely sof-negative or sof-positive strains; with sof-negative strains demonstrating differential seasonal preference for infection, consistent with the recently demonstrated differential seasonal preference based on phylogenetic clustering of full-length M proteins. This might relate to the differences in GAS strain compositions found in different geographic settings and could further inform prevention strategies.
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Oppegaard O, Mylvaganam H, Skrede S, Lindemann PC, Kittang BR. Emergence of a Streptococcus dysgalactiae subspecies equisimilis stG62647-lineage associated with severe clinical manifestations. Sci Rep 2017; 7:7589. [PMID: 28790435 PMCID: PMC5548910 DOI: 10.1038/s41598-017-08162-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/07/2017] [Indexed: 12/03/2022] Open
Abstract
Increasing incidence rates of invasive Streptococcus dysgalactiae subspecies equisimilis (SDSE) infections have been reported worldwide, but the evolutionary mechanisms underlying this development remain elusive. Through prospective surveillance of invasive SDSE infections in western Norway, we observed the emergence of a novel and virulent SDSE genotype, stG62647. This emm-type, rarely encountered as a cause of invasive disease during 1999–2012, emerged in 2013 as the predominant SDSE-genotype. The stG62647-infections were associated with an aggressive clinical course, including the occurrence of streptococcal toxic shock syndrome, necrotizing soft-tissue infections and endocarditis. All the invasive stG62647-isolates were subjected to whole genome sequencing, attempting to explore the genetic events underpinning its epidemicity. Although 10% of the genomes was unique for stG62647-genotype, notably 18 out of 19 isolates contained a disrupted streptococcal invasive locus (sil) due to the insertion of a transposase, IS1548, into the silB-gene. We postulate that the virulence of stG6267-isolates could be partly attributable to the abrogation of the attenuating control normally exerted by this regulon, although experimental verification was not performed. To the best of our knowledge, this is the first study employing large scale whole genome sequencing to illuminate the genetic landscape of epidemic lineages in SDSE.
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Affiliation(s)
- Oddvar Oppegaard
- Department of Medicine, Haukeland University Hospital, Bergen, Norway. .,Department of Clinical Science, University of Bergen, Bergen, Norway.
| | - Haima Mylvaganam
- Department of Microbiology, Haukeland University Hospital, Bergen, Norway
| | - Steinar Skrede
- Department of Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
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Tsuyuki Y, Kurita G, Murata Y, Goto M, Takahashi T. Identification of Group G Streptococcal Isolates from Companion Animals in Japan and Their Antimicrobial Resistance Patterns. Jpn J Infect Dis 2016; 70:394-398. [PMID: 28003600 DOI: 10.7883/yoken.jjid.2016.375] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, we conducted a species-level identification of group G streptococcal (GGS) isolates from companion animals in Japan and analyzed antimicrobial resistance (AMR) patterns. Strains were isolated from sterile and non-sterile specimens collected from 72 animals with clinical signs or symptoms in April-May, 2015. We identified the strain by 16S rRNA sequencing, mass spectrometry (MS), and an automated method based on their biochemical properties. Antimicrobial susceptibility was determined using the broth microdilution method and E-test. AMR determinants (erm(A), erm(B), mef(A), tet(M), tet(O), tet(K), tet(L), and tet(S)) in corresponding resistant isolates were amplified by PCR. The 16S rRNA sequencing identified the GGS species as Streptococcus canis (n = 68), Streptococcus dysgalactiae subsp. equisimilis (n = 3), and S. dysgalactiae subsp. dysgalactiae (n = 1). However, there were discrepancies between the sequencing data and both the MS and automated identification data. MS and the automated biochemical technique identified 18 and 37 of the 68 sequencing-identified S. canis strains, respectively. The AMR rates were 20.8% for tetracycline and 5.6% for clarithromycin, with minimum inhibitory concentrations (MIC)50 -MIC90 of 2-64 and ≤ 0.12-0.25μg/mL, respectively. AMR genotyping showed single or combined genotypes: erm(B) or tet(M)-tet(O)-tet(S). Our findings show the unique characteristics of GGS isolates from companion animals in Japan in terms of species-level identification and AMR patterns.
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Affiliation(s)
- Yuzo Tsuyuki
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University.,Division of Clinical Laboratory, Sanritsu Zelkova Veterinary Laboratory
| | | | | | - Mieko Goto
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Kitasato Institute for Life Sciences, Kitasato University
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Species and emm-type distribution of group C and G streptococci from different sites of isolation. Diagn Microbiol Infect Dis 2016; 86:467-469. [DOI: 10.1016/j.diagmicrobio.2016.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/31/2016] [Accepted: 09/12/2016] [Indexed: 11/22/2022]
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Traverso F, Blanco A, Villalón P, Beratz N, Sáez Nieto JA, Lopardo H. Molecular characterization of invasive Streptococcus dysgalactiae subsp. equisimilis. Multicenter study: Argentina 2011-2012. Rev Argent Microbiol 2016; 48:279-289. [PMID: 28341023 DOI: 10.1016/j.ram.2016.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/01/2016] [Accepted: 07/31/2016] [Indexed: 11/27/2022] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin [1 mef(A), 3 erm(TR), 1 mef(A)+erm(TR) and 1 erm(TR)+erm(B)] and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline [2 tet(M), 5 tet(M)+tet(O)]. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLSB phenotype.
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Affiliation(s)
- Fernando Traverso
- Servicio de Microbiología, Hospital de Pediatría Prof. Dr. Juan P Garrahan, Buenos Aires, Argentina; Nueva Clínica Chacabuco, Tandil, Buenos Aires, Argentina; Servicio de Neumotisiología, Tandil, Buenos Aires, Argentina.
| | - Alejandra Blanco
- Servicio de Microbiología, Hospital de Pediatría Prof. Dr. Juan P Garrahan, Buenos Aires, Argentina
| | - Pilar Villalón
- Centro Nacional de Microbiología ISCIII, Majadahonda, Madrid, Spain
| | - Noelia Beratz
- Servicio de Microbiología, Hospital de Pediatría Prof. Dr. Juan P Garrahan, Buenos Aires, Argentina
| | | | - Horacio Lopardo
- Servicio de Microbiología, Hospital de Pediatría Prof. Dr. Juan P Garrahan, Buenos Aires, Argentina
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Wajima T, Morozumi M, Hanada S, Sunaoshi K, Chiba N, Iwata S, Ubukata K. Molecular Characterization of Invasive Streptococcus dysgalactiae subsp. equisimilis, Japan. Emerg Infect Dis 2016; 22:247-54. [PMID: 26760778 PMCID: PMC4734521 DOI: 10.3201/eid2202.141732] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010-March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and features of patient infections. Bacteremia with no identified focus of origin and cellulitis were the most prevalent manifestations; otherwise, clinical manifestations resembled those of S. pyogenes infections. Clinical manifestations also differed by patient's age. SDSE isolates were classified into 34 emm types; stG6792 was most prevalent (27.1%), followed by stG485 and stG245. Mortality rates did not differ according to emm types. Multilocus sequence typing identified 46 sequence types and 12 novel types. Types possessing macrolide- and quinolone-resistance genes were 18.4% and 2.6%, respectively; none showed β-lactam resistance. Among aging populations, invasive SDSE infections are an increasing risk.
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Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon. Sci Rep 2016; 6:31736. [PMID: 27530432 PMCID: PMC4987641 DOI: 10.1038/srep31736] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 07/25/2016] [Indexed: 11/08/2022] Open
Abstract
The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur.
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Molecular characterization and antibiotic resistance of group G streptococci in Israel: comparison of invasive, non-invasive and carriage isolates. Eur J Clin Microbiol Infect Dis 2016; 35:1649-54. [PMID: 27325440 DOI: 10.1007/s10096-016-2705-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/06/2016] [Indexed: 10/21/2022]
Abstract
Beta-hemolytic group G streptococci (GGS) are increasingly recognized as a source of substantial morbidity, causing mild to severe sporadic infections as well as outbreaks. The purpose of this study was to determine the genetic diversity and antibiotic resistance of GGS in Israel in order to aid in prevention and control. A total of 325 GGS isolates were collected in Israel between 2007 and 2011 from three determined settings: (1) carriage (n = 60), an observational longitudinal carriage study in the IF, (2) non-invasive (n = 166), clinical sporadic and epidemic non-invasive cases in the IDF, and (3) invasive (n = 99) cases of bacteremia collected during this period in Israel from a similar age group, at the national Streptococcal Reference Center. All isolates were characterized genetically and by their antibiotic-resistance profile. emm typing revealed 35 distinct types and subtypes among 228 S. dysgalactiae subsp. equisimilis (SDSE) isolates, with high genetic diversity. An additional 97 GGS were identified as Streptococcus anginosus (SAG). The proportion of SDSE was higher in the invasive (100 %) and non-invasive (63.8 %) isolates compared to the carriage ones (38.3 %). Clindamycin, erythromycin, azithromycin and tetracycline resistance was detected in 6.6 %, 8.6 %, 9.7 % and 37.6 % of isolates, respectively. Overall, the most resistant isolates were in the invasive group and the fewest were in the SAG group. Considerable genetic diversity and common antibiotic resistance were revealed among GGS strains which differed according to the epidemiologic settings. Further clinical, epidemiological and basic research of GGS as a pathogen is warranted.
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de Souza JP, Santos AR, de Paula GR, Barros RR. Antimicrobial susceptibility and genetic relationships among Streptococcus dysgalactiae subsp. equisimilis isolates in Rio de Janeiro. Infect Dis (Lond) 2016; 48:676-81. [PMID: 27301015 DOI: 10.1080/23744235.2016.1192680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been increasingly associated with several infectious diseases, ranging from pharyngitis to life-threatening conditions, such as necrotizing fasciitis and streptococcal toxic shock syndrome. However, its molecular epidemiology in some geographical areas remains unclear. METHODS In this study, 44 isolates of SDSE, recovered from noninvasive infections (37) and from carriage (7), during 2008-2013, were submitted to antimicrobial susceptibility testing, emm typing and pulsed-field gel electrophoresis (PFGE) analysis. RESULTS All isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin. Resistance rates to erythromycin was 18.2% and to clindamycin was 6.8%, while 38.7% of the isolates were tetracycline non-susceptible. Macrolide resistance phenotypes were M (5 isolates), iMLSB (2) and cMLSB (1), associated with mefA/E, ermA and ermB genotypes, respectively. Seventeen emm types with 21 subtypes were found, but 6 types (stG653.0, stC1400.0 with three subtypes, stC839.0, stC36.0 with two subtypes, stG480.0 and stG840.0) were detected in 70.4% of the isolates. Six new emm subtypes were identified (stC1400.12, stC1400.13, emm152.1, emm152.2, stG652.6 and stG6792.5). Twenty-five PFGE profiles were obtained from 39 isolates. CONCLUSIONS Congruence between both typing systems was observed, since the majority of isolates belonging to a given emm type clustered together by PFGE. Clones (at least 80% similarity) were also observed among isolates with different emm types, probably due to horizontal recombination of the emm gene. Erythromycin-resistant isolates harbored diverse emm genes and generated different PFGE profiles, showing a polyclonal dissemination of such characteristic among SDSE isolates.
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Affiliation(s)
- José Paulo de Souza
- a Departmento de Microbiologia e Parasitologia , Instituto Biomédico, Universidade Federal Fluminense , Niterói , Brazil
| | - Amanda Ribeiro Santos
- a Departmento de Microbiologia e Parasitologia , Instituto Biomédico, Universidade Federal Fluminense , Niterói , Brazil
| | | | - Rosana Rocha Barros
- a Departmento de Microbiologia e Parasitologia , Instituto Biomédico, Universidade Federal Fluminense , Niterói , Brazil
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Fujita T, Horiuchi A, Ogawa M, Yoshida H, Hirose Y, Nagano N, Takahashi T. Genetic Diversity in Streptococcus dysgalactiae subsp. equisimilis Isolates from Patients with Invasive and Noninvasive Infections in a Japanese University Hospital (2014-2015). Jpn J Infect Dis 2016; 70:100-104. [PMID: 27000456 DOI: 10.7883/yoken.jjid.2015.602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates with β-hemolysis and carbohydrate groups G or C are increasingly recovered from invasive infections in Japan. The aim of this study was to determine the epidemiological characteristics of SDSE isolates circulating locally among patients with invasive and noninvasive infections. We selected groups G/C β-hemolytic streptococci from a repository at the Clinical Laboratory of Kitasato University Medical Center, from May 2014 through April 2015. Thirteen isolates were identified as SDSE based on the data from API-20 Strep and 16S rRNA sequencing. The samples were from 7 sterile specimens (blood) and 6 non-sterile specimens (pus/sputum/vaginal secretion). Information about the patients with invasive or noninvasive SDSE infections was retrieved from their medical charts. We performed emm genotyping, multilocus sequence typing, a dendrogram analysis of the samples using pulsed-field gel electrophoresis (PFGE), and amplifications of the streptococcal inhibitor of a complement-mediated cell lysis-like gene (sicG) and antimicrobial resistance determinants. We identified 8 different emm genotypes, 8 different sequence types, including 4 novel types, 9 different groups in the PFGE dendrogram, the presence or absence of sicG, and 4 different resistance genotypes. Our observations indicate genetic diversity in SDSE isolates from patients with invasive and noninvasive infections in a Japanese university hospital (2014-2015).
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Affiliation(s)
- Tomohiro Fujita
- Department of Infection Control and Prevention, Kitasato University Medical Center
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Lu B, Fang Y, Huang L, Diao B, Du X, Kan B, Cui Y, Zhu F, Li D, Wang D. Molecular characterization and antibiotic resistance of clinical Streptococcus dysgalactiae subsp. equisimilis in Beijing, China. INFECTION GENETICS AND EVOLUTION 2016; 40:119-125. [PMID: 26925701 DOI: 10.1016/j.meegid.2016.01.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/14/2016] [Accepted: 01/31/2016] [Indexed: 10/22/2022]
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) is presently considered as a human pathogen associated with clinical infection. We characterized 56 SDSE isolates collected from two tertiary hospitals in Beijing, China. Sixteen distinct emm types/subtypes were detected, dominated by stG245.0 (32.1%), stG652.0 (10.7%), stG6.1 (10.7%) and stG485.0 (10.7%), and a novel stG840.0 variant type was identified. All isolates possessed virulence genes of sagA and scpA, and most carried slo (98.2%), ska (98.2%) and speG(dys) (35.7%). By multilocus sequence typing (MLST) analysis, 17 individual sequence types (STs) were distinguished, including 7 newly-identified STs (26.8% of isolates), of which ST127 (30.4%), ST7 (12.5%) and ST44 (10.7%) dominated. Meanwhile, pulsed-field gel electrophoresis (PFGE) analysis revealed 33 pattern types (PTs), which were further combined into 16 pattern clusters (PCs), and 59.3% of isolates were distributed into 2 dominant PCs. Notably, emm types had both close relationship and consistency with STs and PFGE PCs. Furthermore, of 56 SDSE isolates, the predominant antibiotic resistances were erythromycin (71.4%), clindamycin (71.4%) and tetracycline (60.7%). Correspondingly, the prevalent resistance genes of macrolide and tetracycline were erm(B) (78.6%) and tet(M) (73.2%). In addition, multiple point mutations of parC, one of fluoroquinolone resistance genes, were observed (accounting for 75%), and were divided into 12 types, with parC 07 as the predominant type. Our data suggested the wide molecular diversity and distinctive regional features of SDSE from clinical infection in Beijing, China.
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Affiliation(s)
- Binghuai Lu
- Department of Laboratory Medicine, Civil Aviation General Hospital, Beijing 100123, China.
| | - Yujie Fang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Lei Huang
- Department of Laboratory Medicine, First Hospital, Peking University, Beijing 100034, China
| | - Baowei Diao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Xiaoli Du
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Biao Kan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China
| | - Yanchao Cui
- Department of Laboratory Medicine, Civil Aviation General Hospital, Beijing 100123, China
| | - Fengxia Zhu
- Department of Laboratory Medicine, Civil Aviation General Hospital, Beijing 100123, China
| | - Dong Li
- Department of Laboratory Medicine, Civil Aviation General Hospital, Beijing 100123, China
| | - Duochun Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
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Siemens N, Kittang BR, Chakrakodi B, Oppegaard O, Johansson L, Bruun T, Mylvaganam H, Svensson M, Skrede S, Norrby-Teglund A. Increased cytotoxicity and streptolysin O activity in group G streptococcal strains causing invasive tissue infections. Sci Rep 2015; 5:16945. [PMID: 26601609 PMCID: PMC4658506 DOI: 10.1038/srep16945] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/22/2015] [Indexed: 11/09/2022] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) has emerged as an important cause of severe skin and soft tissue infections, but little is known of the pathogenic mechanisms underlying tissue pathology. Patient samples and a collection of invasive and non-invasive group G SDSE strains (n = 69) were analyzed with respect to virulence factor expression and cytotoxic or inflammatory effects on human cells and 3D skin tissue models. SDSE strains efficiently infected the 3D-skin model and severe tissue pathology, inflammatory responses and altered production of host structural framework proteins associated with epithelial barrier integrity were evident already at 8 hours post-infection. Invasive strains were significantly more cytotoxic towards keratinocytes and expressed higher Streptokinase and Streptolysin O (SLO) activities, as compared to non-invasive strains. The opposite was true for Streptolysin S (SLS). Fractionation and proteomic analysis of the cytotoxic fractions implicated SLO as a factor likely contributing to the keratinocyte cytotoxicity and tissue pathology. Analyses of patient tissue biopsies revealed massive bacterial load, high expression of slo, as well as immune cell infiltration and pro-inflammatory markers. Our findings suggest the contribution of SLO to epithelial cytotoxicity and tissue pathology in SDSE tissue infections.
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Affiliation(s)
- Nikolai Siemens
- Center for Infectious Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Bård R Kittang
- Haraldsplass Deaconess Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Bhavya Chakrakodi
- Center for Infectious Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Oddvar Oppegaard
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Linda Johansson
- Center for Infectious Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Trond Bruun
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Haima Mylvaganam
- Department of Microbiology, Haukeland University Hospital, Bergen, Norway
| | | | - Mattias Svensson
- Center for Infectious Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Steiner Skrede
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Medicine, Haukeland University Hospital, Bergen, Norway
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Draft Genome Sequences of Four Genetically Distinct Human Isolates of Streptococcus dysgalactiae subsp. equisimilis. GENOME ANNOUNCEMENTS 2015; 3:3/5/e01139-15. [PMID: 26430051 PMCID: PMC4591323 DOI: 10.1128/genomea.01139-15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
β-Hemolytic group C and group G streptococci (GCS-GGS; Streptococcus dysgalactiae subsp. equisimilis) emerged as human pathogens in the late 1970s. We report here the draft genome sequences of four genetically distinct human strains of GCS-GGS isolated between the 1960s and 1980s. Comparative analysis of these genomes may provide a deeper understanding of GCS-GGS genome and virulence evolution.
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Bessen DE, McShan WM, Nguyen SV, Shetty A, Agrawal S, Tettelin H. Molecular epidemiology and genomics of group A Streptococcus. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2015; 33:393-418. [PMID: 25460818 PMCID: PMC4416080 DOI: 10.1016/j.meegid.2014.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/11/2014] [Accepted: 10/13/2014] [Indexed: 12/15/2022]
Abstract
Streptococcus pyogenes (group A Streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed.
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Affiliation(s)
- Debra E Bessen
- Department of Microbiology & Immunology, New York Medical College, Valhalla, NY 10595, USA.
| | - W Michael McShan
- University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences, College of Pharmacy, Oklahoma City, OK 73117, USA.
| | - Scott V Nguyen
- University of Oklahoma Health Sciences Center, Department of Pharmaceutical Sciences, College of Pharmacy, Oklahoma City, OK 73117, USA.
| | - Amol Shetty
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Sonia Agrawal
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Silva LG, Genteluci GL, Corrêa de Mattos M, Glatthardt T, Sá Figueiredo AM, Ferreira-Carvalho BT. Group C Streptococcus dysgalactiae subsp. equisimilis in south-east Brazil: genetic diversity, resistance profile and the first report of human and equine isolates belonging to the same multilocus sequence typing lineage. J Med Microbiol 2015; 64:551-558. [DOI: 10.1099/jmm.0.000052] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/08/2015] [Indexed: 11/18/2022] Open
Affiliation(s)
- Ligia Guedes Silva
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, RJ, Brazil
| | | | - Marcos Corrêa de Mattos
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, RJ, Brazil
| | - Thaís Glatthardt
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, RJ, Brazil
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McNeilly CL, McMillan DJ. Horizontal gene transfer and recombination in Streptococcus dysgalactiae subsp. equisimilis. Front Microbiol 2014; 5:676. [PMID: 25566202 PMCID: PMC4266089 DOI: 10.3389/fmicb.2014.00676] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 11/19/2014] [Indexed: 11/13/2022] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a human pathogen that colonizes the skin or throat, and causes a range of diseases from relatively benign pharyngitis to potentially fatal invasive diseases. While not as virulent as the close relative Streptococcus pyogenes the two share a number of virulence factors and are known to coexist in a human host. Both pre- and post-genomic studies have revealed that horizontal gene transfer (HGT) and recombination occurs between these two organisms and plays a major role in shaping the population structure of SDSE. This review summarizes our current knowledge of HGT and recombination in the evolution of SDSE.
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Affiliation(s)
- Celia L McNeilly
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD, Australia
| | - David J McMillan
- Inflammation and Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast , Maroochydore, QLD, Australia
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Lo HH, Cheng WS. Distribution of virulence factors and association with emm polymorphism or isolation site among beta-hemolytic group G Streptococcus dysgalactiae subspecies equisimilis. APMIS 2014; 123:45-52. [PMID: 25244428 DOI: 10.1111/apm.12305] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 06/23/2014] [Indexed: 11/29/2022]
Abstract
Distribution of virulence factors and association with emm polymorphism or isolation site among beta-hemolytic group G Streptococcus dysgalactiae subspecies equisimilis. Streptococcus dysgalactiae subspecies equisimilis (SDSE), the dominant human pathogenic species among group G streptococci, is the causative agent of several invasive and non-invasive diseases worldwide. However, limited information is available about the distribution of virulence factors among SDSE isolates, or their association with emm types and the isolation sites. In this study, 246 beta-hemolytic group G SDSE isolates collected in central Taiwan between February 2007 and August 2011 were under investigation. Of these, 66 isolates were obtained from normally sterile sites and 180 from non-sterile sites. emm typing revealed 32 types, with the most prevalent one being stG10.0 (39.8%), followed by stG245.0 (15.4%), stG840.0 (12.2%), stG6.1 (7.7%), and stG652.0 (4.1%). The virulence genes lmb (encoding laminin-binding protein), gapC (glyceraldehyde 3-phosphate dehydrogenase), sagA (streptolysin S), and hylB (hyaluronidase) existed in all isolates. Also, 99.2% of the isolates possessed slo (streptolysin O) and scpA (C5a peptidase) genes. In addition, 72.8%, 14.6%, 9.4%, and 2.4% of the isolates possessed the genes ska (streptokinase), cbp (putative collagen-binding protein, SDEG_1781), fbp (putative fibronectin-binding protein, SDEG_0161), and sicG (streptococcal inhibitor of complement), respectively. The only superantigen gene detected was spegg (streptococcus pyrogenic exotoxin G(dys) ), which was possessed by 74.4% of the isolates; these isolates correlated with non-sterile sites. Positive correlations were observed between the following emm types and virulence genes: stG10.0 and stG840.0 with spegg, stG6.1 and stG652.0 with ska, and stG840.0 with cbp. On the other hand, negative correlations were observed between the following: stG245.0, stG6.1, and stG652.0 types with spegg, stG10.0 with ska, and stG10.0, stG245.0, and stG6.1 types with cbp. The prevalence of emm types of SDSE in central Taiwan was investigated for the first time. Moreover, the distribution of virulence factors among beta-hemolytic group G SDSE isolates, as well as their association with emm types or isolation sites were also examined.
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Affiliation(s)
- Hsueh-Hsia Lo
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan
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Streptococcus dysgalactiae subsp. equisimilis bacteremia: an emerging infection. Eur J Clin Microbiol Infect Dis 2014; 33:1303-10. [PMID: 24682845 DOI: 10.1007/s10096-014-2092-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
The importance of group C and G Streptococcus dysgalactiae subspecies equisimilis (S. dysgalactiae subsp. equisimilis) as a significant pathogen has recently been better recognized. S. dysgalactiae subsp. equisimilis disease can range in severity from milder skin and soft-tissue conditions such as wound infection, erysipelas, and cellulitis, to life-threatening necrotizing fasciitis and streptococcal toxic shock syndrome, thus sharing the clinical picture with S. pyogenes. The most common clinical manifestation of bacteremia is cellulitis. An increase in the incidence of S. dysgalactiae subsp. equisimilis bacteremia has been recognized. Invasive forms of this infection are most commonly found in elderly patients with underlying comorbidities and skin breakdown. The case fatality in bacteremia has been reported to be 15-18%. In this review, the epidemiology, clinical characteristics, and emm types of S. dysgalactiae subsp. equisimilis bacteremia are summarized.
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DrsG from Streptococcus dysgalactiae subsp. equisimilis inhibits the antimicrobial peptide LL-37. Infect Immun 2014; 82:2337-44. [PMID: 24664506 DOI: 10.1128/iai.01411-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SIC and DRS are related proteins present in only 4 of the >200 Streptococcus pyogenes emm types. These proteins inhibit complement-mediated lysis and/or the activity of certain antimicrobial peptides (AMPs). A gene encoding a homologue of these proteins, herein called DrsG, has been identified in the related bacterium Streptococcus dysgalactiae subsp. equisimilis. Here we show that geographically dispersed isolates representing 14 of 50 emm types examined possess variants of drsG. However, not all isolates within the drsG-positive emm types possess the gene. Sequence comparisons also revealed a high degree of conservation in different S. dysgalactiae subsp. equisimilis emm types. To examine the biological activity of DrsG, recombinant versions of two major DrsG variants, DrsGS and DrsGL, were expressed and purified. Western blot analysis using antisera raised to these proteins demonstrated both variants to be expressed and secreted into culture supernatants. Unlike SIC, but similar to DRS, DrsG does not inhibit complement-mediated lysis. However, like both SIC and DRS, DrsG is a ligand of the cathelicidin LL-37 and is inhibitory to its bactericidal activity in in vitro assays. Conservation of prolines in the C-terminal region also suggests that these residues are important in the biology of this family of proteins. This is the first report demonstrating the activity of an AMP-inhibitory protein in S. dysgalactiae subsp. equisimilis and suggests that inhibition of AMP activity is the primary function of this family of proteins. The acquisition of the complement-inhibitory activity of SIC may reflect its continuing evolution.
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Gherardi G, Imperi M, Palmieri C, Magi G, Facinelli B, Baldassarri L, Pataracchia M, Creti R. Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources. J Med Microbiol 2014; 63:90-98. [DOI: 10.1099/jmm.0.062109-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). A collection of 54 SDSE strains isolated in Italy in the years 2000–2010 from different sources (paediatric throat carriage, invasive and non-invasive diseases) was characterized by emm typing and pulsed-field gel electrophoresis (PFGE) analysis. The virulence repertoire was evaluated by PCR for the presence of GAS superantigen (spe) genes, the streptolysin S (sagA) gene, the group G fibronectin-binding protein (gfbA) gene and GAS–GBS alpha-like protein family (alp) genes; moreover, the ability to invade human epithelial cells was investigated. Resistance to tetracycline, erythromycin and clindamycin was assessed. The combined use of emm typing and PFGE proved to be a reliable strategy for the epidemiological analysis of SDSE isolates. The most frequent emm types were the same as those more frequently reported in other studies, thus indicating the diffusion of a limited number of a few successful emm types fit to disseminate in humans. The speG gene was detected in SDSE strains of different genetic backgrounds. Erythromycin resistance determined by the erm(T) gene, and the unusual, foggy MLSB phenotype, observed in one and seven strains, respectively, have never previously, to our knowledge, been reported in SDSE. Moreover, a new member of the alp family was identified. The identification of new antibiotic and virulence determinants, despite the small size of the sample analysed, shows the importance of constant attention to monitoring the extent of lateral gene transfer in this emerging pathogen.
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Affiliation(s)
- Giovanni Gherardi
- Dipartimento di Centro Integrato di Ricerca (CIR), Università Campus Bio-Medico, Rome, Italy
| | - Monica Imperi
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - Claudio Palmieri
- Dipartimento di Scienze Biomediche e Sanità Pubblica, Sezione Microbiologia, Università Politecnica delle Marche, Ancona, Italy
| | - Gloria Magi
- Dipartimento di Scienze Biomediche e Sanità Pubblica, Sezione Microbiologia, Università Politecnica delle Marche, Ancona, Italy
| | - Bruna Facinelli
- Dipartimento di Scienze Biomediche e Sanità Pubblica, Sezione Microbiologia, Università Politecnica delle Marche, Ancona, Italy
| | - Lucilla Baldassarri
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - Marco Pataracchia
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - Roberta Creti
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
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Lambertsen LM, Ingels H, Schønheyder HC, Hoffmann S. Nationwide laboratory-based surveillance of invasive beta-haemolytic streptococci in Denmark from 2005 to 2011. Clin Microbiol Infect 2013; 20:O216-23. [PMID: 24125634 PMCID: PMC4232002 DOI: 10.1111/1469-0691.12378] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/26/2013] [Accepted: 08/24/2013] [Indexed: 12/02/2022]
Abstract
The aim of this work was to describe national surveillance of invasive beta-haemolytic streptococci (BHS) in Denmark and to report overall trends and major findings by groups and types of BHS causing laboratory-confirmed disease from 2005 to 2011. A total of 3063 BHS isolates were received from 2872 patients. Based on confirmed cases the overall annual incidence increased from 6.2 to 8.9 per 100 000 persons between 2005 and 2011. In 2011 the incidences of group A, B, C and G streptococci were 3.1, 2.3, 0.9 and 2.6 per 100 000 persons, respectively. An increase was observed for all groups of BHS, but in particular for group G in men above 65 years of age. Among group A streptococci (GAS), five T-types (1, 28,12, 3,13,B3264 and B3264) represented 71% and five emm-types (1, 28, 3, 89 and 12) 76% of all isolates. Among group B streptococci (GBS) four types (III, Ia, V, Ib) represented 79% of the isolates. Potential coverage for future vaccines against GAS and GBS disease was 76% compared with the 26-valent GAS vaccine and 89% based on GBS serotypes Ia, Ib, II, III and V. The number of reported cases of invasive BHS disease increased in Denmark from 2005 to 2011. Nationwide laboratory-based surveillance of BHS is required to monitor epidemiological changes, explore potential outbreaks and determine potential vaccine coverage.
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Affiliation(s)
- L M Lambertsen
- National Neisseria and Streptococcus Reference (NSR), Statens Serum Institut, Copenhagen, Denmark
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Oppegaard O, Mylvaganam H, Skrede S, Langeland N, Kittang BR. Sequence diversity of sicG among group C and G Streptococcus dysgalactiae subspecies equisimilis isolates associated with human infections in western Norway. Eur J Clin Microbiol Infect Dis 2013; 33:273-7. [PMID: 24019161 DOI: 10.1007/s10096-013-1955-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/08/2013] [Indexed: 11/24/2022]
Abstract
Streptococcal inhibitor of complement (SIC) and distantly related to SIC (DRS) are well-characterized extracellular virulence factors produced by only a few emm types among group A streptococci. The prevalence and sequence variations of the sic-like gene (sicG) in clinical samples of group C and G Streptococcus dysgalactiae subspecies equisimilis (SDSE), however, have not been widely investigated. We constructed primers targeting sicG and screened 129 geographically matched and previously emm-typed non-invasive (n = 64) and invasive (n = 65) SDSE isolates for the presence of this gene. sicG was detected in seven non-invasive and eight invasive isolates belonging to eight different emm types. Within five of these emm types, sicG-negative isolates were also detected. All three isolates of stG2078.0 possessed sicG and were associated with severe soft tissue infections. Altogether, six sicG alleles (sicG1-6) were identified, and sequence variations were mainly caused by single nucleotide polymorphisms and deletion/insertion mutations. sicG1-6 were predicted to encode SICG proteins of varying length, composition, and homology with SIC and DRS proteins of group A streptococci. Our findings indicate an unpredictable association between sicG and emm type, a limited distribution and substantial sequence diversity of sicG, and no obvious relation between its presence and disease severity.
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Affiliation(s)
- O Oppegaard
- Department of Medicine, Haukeland University Hospital, Jonas Lies vei 1, 5021, Bergen, Norway,
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Pérez-Losada M, Cabezas P, Castro-Nallar E, Crandall KA. Pathogen typing in the genomics era: MLST and the future of molecular epidemiology. INFECTION GENETICS AND EVOLUTION 2013; 16:38-53. [PMID: 23357583 DOI: 10.1016/j.meegid.2013.01.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/11/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
Abstract
Multi-locus sequence typing (MLST) is a high-resolution genetic typing approach to identify species and strains of pathogens impacting human health, agriculture (animals and plants), and biosafety. In this review, we outline the general concepts behind MLST, molecular approaches for obtaining MLST data, analytical approaches for MLST data, and the contributions MLST studies have made in a wide variety of areas. We then look at the future of MLST and their relative strengths and weaknesses with respect to whole genome sequence typing approaches that are moving into the research arena at an ever-increasing pace. Throughout the paper, we provide exemplar references of these various aspects of MLST. The literature is simply too vast to make this review comprehensive, nevertheless, we have attempted to include enough references in a variety of key areas to introduce the reader to the broad applications and complications of MLST data.
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Affiliation(s)
- Marcos Pérez-Losada
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal.
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Multilocus sequence analysis of Streptococcus canis confirms the zoonotic origin of human infections and reveals genetic exchange with Streptococcus dysgalactiae subsp. equisimilis. J Clin Microbiol 2013; 51:1099-109. [PMID: 23345291 DOI: 10.1128/jcm.02912-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection.
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Choi SC, Rasmussen MD, Hubisz MJ, Gronau I, Stanhope MJ, Siepel A. Replacing and additive horizontal gene transfer in Streptococcus. Mol Biol Evol 2012; 29:3309-20. [PMID: 22617954 DOI: 10.1093/molbev/mss138] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The prominent role of Horizontal Gene Transfer (HGT) in the evolution of bacteria is now well documented, but few studies have differentiated between evolutionary events that predominantly cause genes in one lineage to be replaced by homologs from another lineage ("replacing HGT") and events that result in the addition of substantial new genomic material ("additive HGT"). Here in, we make use of the distinct phylogenetic signatures of replacing and additive HGTs in a genome-wide study of the important human pathogen Streptococcus pyogenes (SPY) and its close relatives S. dysgalactiae subspecies equisimilis (SDE) and S. dysgalactiae subspecies dysgalactiae (SDD). Using recently developed statistical models and computational methods, we find evidence for abundant gene flow of both kinds within each of the SPY and SDE clades and of reduced levels of exchange between SPY and SDD. In addition, our analysis strongly supports a pronounced asymmetry in SPY-SDE gene flow, favoring the SPY-to-SDE direction. This finding is of particular interest in light of the recent increase in virulence of pathogenic SDE. We find much stronger evidence for SPY-SDE gene flow among replacing than among additive transfers, suggesting a primary influence from homologous recombination between co-occurring SPY and SDE cells in human hosts. Putative virulence genes are correlated with transfer events, but this correlation is found to be driven by additive, not replacing, HGTs. The genes affected by additive HGTs are enriched for functions having to do with transposition, recombination, and DNA integration, consistent with previous findings, whereas replacing HGTs seen to influence a more diverse set of genes. Additive transfers are also found to be associated with evidence of positive selection. These findings shed new light on the manner in which HGT has shaped pathogenic bacterial genomes.
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Affiliation(s)
- Sang Chul Choi
- Department of Biological Statistics and Computational Biology, Cornell University
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Dalhoff A. Resistance surveillance studies: a multifaceted problem--the fluoroquinolone example. Infection 2012; 40:239-62. [PMID: 22460782 DOI: 10.1007/s15010-012-0257-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 03/09/2012] [Indexed: 02/06/2023]
Abstract
INTRODUCTION This review summarizes data on the fluoroquinolone resistance epidemiology published in the previous 5 years. MATERIALS AND METHODS The data reviewed are stratified according to the different prescription patterns by either primary- or tertiary-care givers and by indication. Global surveillance studies demonstrate that fluoroquinolone- resistance rates increased in the past several years in almost all bacterial species except Staphylococcus pneumoniae and Haemophilus influenzae causing community-acquired respiratory tract infections (CARTIs), as well as Enterobacteriaceae causing community-acquired urinary tract infections. Geographically and quantitatively varying fluoroquinolone resistance rates were recorded among Gram-positive and Gram-negative pathogens causing healthcare-associated respiratory tract infections. One- to two-thirds of Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) were fluoroquinolone resistant too, thus, limiting the fluoroquinolone use in the treatment of community- as well as healthcare-acquired urinary tract and intra-abdominal infections. The remaining ESBL-producing or plasmid-mediated quinolone resistance mechanisms harboring Enterobacteriaceae were low-level quinolone resistant. Furthermore, 10-30 % of H. influenzae and S. pneumoniae causing CARTIs harbored first-step quinolone resistance determining region (QRDR) mutations. These mutants pass susceptibility testing unnoticed and are primed to acquire high-level fluoroquinolone resistance rapidly, thus, putting the patient at risk. The continued increase in fluoroquinolone resistance affects patient management and necessitates changes in some current guidelines for the treatment of intra-abdominal infections or even precludes the use of fluoroquinolones in certain indications like gonorrhea and pelvic inflammatory diseases in those geographic areas in which fluoroquinolone resistance rates and/or ESBL production is high. Fluoroquinolone resistance has been selected among the commensal flora colonizing the gut, nose, oropharynx, and skin, so that horizontal gene transfer between the commensal flora and the offending pathogen as well as inter- and intraspecies recombinations contribute to the emergence and spread of fluoroquinolone resistance among pathogenic streptococci. Although interspecies recombinations are not yet the major cause for the emergence of fluoroquinolone resistance, its existence indicates that a large reservoir of fluoroquinolone resistance exists. Thus, a scenario resembling that of a worldwide spread of β-lactam resistance in pneumococci is conceivable. However, many resistance surveillance studies suffer from inaccuracies like the sampling of a selected patient population, restricted geographical sampling, and undefined requirements of the user, so that the results are biased. The number of national centers is most often limited with one to two participating laboratories, so that such studies are point prevalence but not surveillance studies. Selected samples are analyzed predominantly as either hospitalized patients or patients at risk or those in whom therapy failed are sampled; however, fluoroquinolones are most frequently prescribed by the general practitioner. Selected sampling results in a significant over-estimation of fluoroquinolone resistance in outpatients. Furthermore, the requirements of the users are often not met; the prescribing physician, the microbiologist, the infection control specialist, public health and regulatory authorities, and the pharmaceutical industry have diverse interests, which, however, are not addressed by different designs of a surveillance study. Tools should be developed to provide customer-specific datasets. CONCLUSION Consequently, most surveillance studies suffer from well recognized but uncorrected biases or inaccuracies. Nevertheless, they provide important information that allows the identification of trends in pathogen incidence and antimicrobial resistance.
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Affiliation(s)
- A Dalhoff
- Institute for Infection-Medicine, Christian-Albrechts University of Kiel and University Medical Center Schleswig-Holstein, Brunswiker Str. 4, 24105, Kiel, Germany.
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Yin J, Yu S, Liu X, Li Y, Gao W, Zhou L, Ji L, Shen X, Yang Y. Molecular characterization of group G Streptococcus dysgalactiae subsp. equisimilis recovered from patients and healthy people in China. Diagn Microbiol Infect Dis 2012; 72:41-6. [DOI: 10.1016/j.diagmicrobio.2011.09.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2011] [Revised: 09/19/2011] [Accepted: 09/23/2011] [Indexed: 11/26/2022]
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Delineation of Streptococcus dysgalactiae, its subspecies, and its clinical and phylogenetic relationship to Streptococcus pyogenes. J Clin Microbiol 2011; 50:113-26. [PMID: 22075580 DOI: 10.1128/jcm.05900-11] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The taxonomic status and structure of Streptococcus dysgalactiae have been the object of much confusion. Bacteria belonging to this species are usually referred to as Lancefield group C or group G streptococci in clinical settings in spite of the fact that these terms lack precision and prevent recognition of the exact clinical relevance of these bacteria. The purpose of this study was to develop an improved basis for delineation and identification of the individual species of the pyogenic group of streptococci in the clinical microbiology laboratory, with a special focus on S. dysgalactiae. We critically reexamined the genetic relationships of the species S. dysgalactiae, Streptococcus pyogenes, Streptococcus canis, and Streptococcus equi, which may share Lancefield group antigens, by phylogenetic reconstruction based on multilocus sequence analysis (MLSA) and 16S rRNA gene sequences and by emm typing combined with phenotypic characterization. Analysis of concatenated sequences of seven genes previously used for examination of viridans streptococci distinguished robust and coherent clusters. S. dysgalactiae consists of two separate clusters consistent with the two recognized subspecies dysgalactiae and equisimilis. Both taxa share alleles with S. pyogenes in several housekeeping genes, which invalidates identification based on single-locus sequencing. S. dysgalactiae, S. canis, and S. pyogenes constitute a closely related branch within the genus Streptococcus indicative of recent descent from a common ancestor, while S. equi is highly divergent from other species of the pyogenic group streptococci. The results provide an improved basis for identification of clinically important pyogenic group streptococci and explain the overlapping spectrum of infections caused by the species associated with humans.
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Vähäkuopus S, Vuento R, Siljander T, Syrjänen J, Vuopio J. Distribution of emm types in invasive and non-invasive group A and G streptococci. Eur J Clin Microbiol Infect Dis 2011; 31:1251-6. [DOI: 10.1007/s10096-011-1436-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 09/20/2011] [Indexed: 10/16/2022]
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McMillan DJ, Kaul SY, Bramhachari PV, Smeesters PR, Vu T, Karmarkar MG, Shaila MS, Sriprakash KS. Recombination drives genetic diversification of Streptococcus dysgalactiae subspecies equisimilis in a region of streptococcal endemicity. PLoS One 2011; 6:e21346. [PMID: 21857905 PMCID: PMC3153926 DOI: 10.1371/journal.pone.0021346] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 05/29/2011] [Indexed: 12/02/2022] Open
Abstract
Infection of the skin or throat by Streptococcus dysgalactiae subspecies equisimilis (SDSE) may result in a number of human diseases. To understand mechanisms that give rise to new genetic variants in this species, we used multi-locus sequence typing (MLST) to characterise relationships in the SDSE population from India, a country where streptococcal disease is endemic. The study revealed Indian SDSE isolates have sequence types (STs) predominantly different to those reported from other regions of the world. Emm-ST combinations in India are also largely unique. Split decomposition analysis, the presence of emm-types in unrelated clonal complexes, and analysis of phylogenetic trees based on concatenated sequences all reveal an extensive history of recombination within the population. The ratio of recombination to mutation (r/m) events (11∶1) and per site r/m ratio (41∶1) in this population is twice as high as reported for SDSE from non-endemic regions. Recombination involving the emm-gene is also more frequent than recombination involving housekeeping genes, consistent with diversification of M proteins offering selective advantages to the pathogen. Our data demonstrate that genetic recombination in endemic regions is more frequent than non-endemic regions, and gives rise to novel local SDSE variants, some of which may have increased fitness or pathogenic potential.
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Affiliation(s)
- David J McMillan
- Bacterial Pathogenesis Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland, Australia.
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Kittang BR, Bruun T, Langeland N, Mylvaganam H, Glambek M, Skrede S. Invasive group A, C and G streptococcal disease in western Norway: virulence gene profiles, clinical features and outcomes. Clin Microbiol Infect 2011; 17:358-64. [PMID: 20456456 DOI: 10.1111/j.1469-0691.2010.03253.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Invasive group A streptococcal (iGAS) disease is endemic in Norway, but data on invasive group C and group G streptococcal (iGCS/GGS) disease are lacking. We investigated the characteristics of iGAS and iGCS/GGS infections in western Norway from March 2006 to February 2009. Clinical information was retrospectively obtained from medical records. GAS and GCS/GGS isolates were emm typed and screened for the presence of 11 superantigen (SAg) genes and the gene encoding streptococcal phospholipase A₂ (SlaA). GCS/GGS isolates were also subjected to PCR with primers targeting speG(dys) . Sixty iGAS and 50 iGCS/GGS cases were identified, corresponding to mean annual incidence rates of 5.0 per 100,000 and 4.1 per 100,000 inhabitants, respectively. Skin and soft tissue infections were the most frequent clinical manifestations of both iGAS and iGCS/GGS disease, and 14 iGAS patients (23%) developed necrotizing fasciitis. The 30-day case fatality rates of iGAS and iGCS/GGS disease were 10% and 2%, respectively. emm1, emm3 and emm28 accounted for 53% of the GAS isolates, and these types were associated with severe clinical outcome. SAg gene and SlaA profiles were conserved within most of the GAS emm types, although five profiles were obtained within isolates of emm28. stG643 was the most prevalent GCS/GGS emm type, and speG(dys) was identified in 73% of the GCS/GGS isolates. Neither GAS SAg genes nor SlaA were detected in GCS/GGS. Our findings indicate a considerable burden of both iGAS and iGCS/GGS disease and a high frequency of necrotizing fasciitis caused by GAS in our community.
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Affiliation(s)
- B R Kittang
- Institute of Medicine, University of Bergen, Bergen, Norway.
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