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Schiavolin L, Deneubourg G, Steinmetz J, Smeesters PR, Botteaux A. Group A Streptococcus adaptation to diverse niches: lessons from transcriptomic studies. Crit Rev Microbiol 2024; 50:241-265. [PMID: 38140809 DOI: 10.1080/1040841x.2023.2294905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 12/10/2023] [Indexed: 12/24/2023]
Abstract
Group A Streptococcus (GAS) is a major human pathogen, causing diseases ranging from mild superficial infections of the skin and pharyngeal epithelium to severe systemic and invasive diseases. Moreover, post infection auto-immune sequelae arise by a yet not fully understood mechanism. The ability of GAS to cause a wide variety of infections is linked to the expression of a large set of virulence factors and their transcriptional regulation in response to various physiological environments. The use of transcriptomics, among others -omics technologies, in addition to traditional molecular methods, has led to a better understanding of GAS pathogenesis and host adaptation mechanisms. This review focusing on bacterial transcriptomic provides new insight into gene-expression patterns in vitro, ex vivo and in vivo with an emphasis on metabolic shifts, virulence genes expression and transcriptional regulators role.
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Affiliation(s)
- Lionel Schiavolin
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Geoffrey Deneubourg
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Jenny Steinmetz
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Pierre R Smeesters
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
- Department of Paediatrics, Brussels University Hospital, Academic Children Hospital Queen Fabiola, Université libre de Bruxelles, Brussels, Belgium
| | - Anne Botteaux
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
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2
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Breyer GM, Rocha Jacques da Silva ME, Slaviero M, Albuquerque de Almeida B, Machado Sousa da Silva E, de Queiroz Schmidt VR, Alievi M, Maboni G, Petinatti Pavarini S, Maboni Siqueira F. Genotypic characterization of Streptococcus didelphis causative of fatal infection in white-eared opossums. Lett Appl Microbiol 2023; 76:ovad131. [PMID: 37968138 DOI: 10.1093/lambio/ovad131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/25/2023] [Accepted: 11/14/2023] [Indexed: 11/17/2023]
Abstract
Streptococcus didelphis was once reported as related to severe infections in opossums. Thus, we present the first comprehensive whole-genome characterization of clinical S. didelphis strains isolated from white-eared opossums (Didelphis albiventris). Long-read whole-genome sequencing was performed using the MinION platform, which allowed the prediction of several genomic features. We observed that S. didelphis genomes harbor a cluster for streptolysin biosynthesis and a conserved genomic island with genes involved in transcriptional regulation (arlR) and transmembrane transport (bcrA). Antimicrobial resistance genes for several drug classes were found, including beta-lactam, which is the main antimicrobial class used in Streptococcus spp. infections; however, no phenotypical resistance was observed. In addition, we predicted the presence of 33 virulence factors in the analyzed genomes. High phylogenetic similarity was observed between clinical and reference strains, yet no clonality was suggested. We also proposed dnaN, gki, pros, and xpt as housekeeping candidates to be used in S. didelphis sequence typing. This is the first whole-genome characterization of S. didelphis, whose data provide important insights into its pathogenicity.
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Affiliation(s)
- Gabriela Merker Breyer
- Laboratório de Bacteriologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Maria Eduarda Rocha Jacques da Silva
- Laboratório de Bacteriologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Mônica Slaviero
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Laboratório de Patologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Bruno Albuquerque de Almeida
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Laboratório de Patologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Emanoelly Machado Sousa da Silva
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Laboratório de Patologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Victória Regina de Queiroz Schmidt
- Preservas-Núcleo de Conservação e Reabilitação de Animais Silvestres, Hospital de Clínicas Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Marcelo Alievi
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Preservas-Núcleo de Conservação e Reabilitação de Animais Silvestres, Hospital de Clínicas Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Grazieli Maboni
- Department of Pathobiology, University of Guelph, 50 Stone Road East, NIG 2W1 - Guelph/ON, Canada
| | - Saulo Petinatti Pavarini
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Laboratório de Patologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
| | - Franciele Maboni Siqueira
- Laboratório de Bacteriologia Veterinária, Departamento de Patologia Veterinária, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Rio Grande do Sul, 9090 Bento Gonçalves Avenue, 91540-000 - Porto Alegre/RS, Brazil
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3
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Wilkening RV, Langouët-Astrié C, Severn MM, Federle MJ, Horswill AR. Identifying genetic determinants of Streptococcus pyogenes-host interactions in a murine intact skin infection model. Cell Rep 2023; 42:113332. [PMID: 37889753 PMCID: PMC10841832 DOI: 10.1016/j.celrep.2023.113332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/12/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023] Open
Abstract
Streptococcus pyogenes is an obligate human pathobiont associated with many disease states. Here, we present a model of S. pyogenes infection using intact murine epithelium. We were able to perform RNA sequencing to evaluate genetic changes undertaken by both the bacterium and host at 5 and 24 h post-infection. Analysis of these genomic data demonstrate that S. pyogenes undergoes genetic adaptation to successfully infect the murine epithelium, including changes to metabolism and activation of the Rgg2/Rgg3 quorum-sensing (QS) system. Subsequent experiments demonstrate that an intact Rgg2/Rgg3 QS cascade is necessary to establish a stable superficial skin infection. QS cascade activation results in increased murine morbidity and bacterial burden on the skin. This phenotype is associated with gross changes to the murine skin and with evidence of inflammation. These experiments offer a method to investigate S. pyogenes-epithelial interactions and demonstrate that a well-studied QS pathway is critical to a persistent infection.
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Affiliation(s)
- Reid V Wilkening
- Section of Pediatric Critical Care Medicine, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Microbiology and Immunology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Christophe Langouët-Astrié
- Section of Pulmonary Sciences and Critical Care, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Morgan M Severn
- Department of Microbiology and Immunology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Michael J Federle
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Alexander R Horswill
- Department of Microbiology and Immunology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, CO 80045, USA.
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DebRoy S, Shropshire WC, Vega L, Tran C, Horstmann N, Mukherjee P, Selvaraj-Anand S, Tran TT, Bremer J, Gohel M, Arias CA, Flores AR, Shelburne SA. Identification of distinct impacts of CovS inactivation on the transcriptome of acapsular group A streptococci. mSystems 2023; 8:e0022723. [PMID: 37358280 PMCID: PMC10470059 DOI: 10.1128/msystems.00227-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/11/2023] [Indexed: 06/27/2023] Open
Abstract
Group A streptococcal (GAS) strains causing severe, invasive infections often have mutations in the control of virulence two-component regulatory system (CovRS) which represses capsule production, and high-level capsule production is considered critical to the GAS hypervirulent phenotype. Additionally, based on studies in emm1 GAS, hyperencapsulation is thought to limit transmission of CovRS-mutated strains by reducing GAS adherence to mucosal surfaces. It has recently been identified that about 30% of invasive GAS strains lacks capsule, but there are limited data regarding the impact of CovS inactivation in such acapsular strains. Using publicly available complete genomes (n = 2,455) of invasive GAS strains, we identified similar rates of CovRS inactivation and limited evidence for transmission of CovRS-mutated isolates for both encapsulated and acapsular emm types. Relative to encapsulated GAS, CovS transcriptomes of the prevalent acapsular emm types emm28, emm87, and emm89 revealed unique impacts such as increased transcript levels of genes in the emm/mga region along with decreased transcript levels of pilus operon-encoding genes and the streptokinase-encoding gene ska. CovS inactivation in emm87 and emm89 strains, but not emm28, increased GAS survival in human blood. Moreover, CovS inactivation in acapsular GAS reduced adherence to host epithelial cells. These data suggest that the hypervirulence induced by CovS inactivation in acapsular GAS follows distinct pathways from the better studied encapsulated strains and that factors other than hyperencapsulation may account for the lack of transmission of CovRS-mutated strains. IMPORTANCE Devastating infections due to group A streptococci (GAS) tend to occur sporadically and are often caused by strains that contain mutations in the control of virulence regulatory system (CovRS). In well-studied emm1 GAS, the increased production of capsule induced by CovRS mutation is considered key to both hypervirulence and limited transmissibility by interfering with proteins that mediate attachment to eukaryotic cells. Herein, we show that the rates of covRS mutations and genetic clustering of CovRS-mutated isolates are independent of capsule status. Moreover, we found that CovS inactivation in multiple acapsular GAS emm types results in dramatically altered transcript levels of a diverse array of cell-surface protein-encoding genes and a unique transcriptome relative to encapsulated GAS. These data provide new insights into how a major human pathogen achieves hypervirulence and indicate that factors other than hyperencapsulation likely account for the sporadic nature of the severe GAS disease.
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Affiliation(s)
- Sruti DebRoy
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - William C. Shropshire
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Luis Vega
- Division of Infectious Diseases and Department of Pediatrics, McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital, Houston, Texas, USA
| | - Chau Tran
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Nicola Horstmann
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Piyali Mukherjee
- Division of Infectious Diseases and Department of Pediatrics, McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital, Houston, Texas, USA
| | | | - Truc T. Tran
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
| | - Jordan Bremer
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Marc Gohel
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Cesar A. Arias
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
| | - Anthony R. Flores
- Division of Infectious Diseases and Department of Pediatrics, McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital, Houston, Texas, USA
| | - Samuel A. Shelburne
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Chiang-Ni C, Chen YW, Chen KL, Jiang JX, Shi YA, Hsu CY, Chen YYM, Lai CH, Chiu CH. RopB represses the transcription of speB in the absence of SIP in group A Streptococcus. Life Sci Alliance 2023; 6:e202201809. [PMID: 37001914 PMCID: PMC10071013 DOI: 10.26508/lsa.202201809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023] Open
Abstract
RopB is a quorum-sensing regulator that binds to the SpeB-inducing peptide (SIP) under acidic conditions. SIP is known to be degraded by the endopeptidase PepO, whose transcription is repressed by the CovR/CovS two-component regulatory system. Both SIP-bound RopB (RopB-SIP) and SIP-free RopB (apo-RopB) can bind to the speB promoter; however, only RopB-SIP activates speB transcription. In this study, we found that the SpeB expression was higher in the ropB mutant than in the SIP-inactivated (SIP*) mutant. Furthermore, the deletion of ropB in the SIP* mutant derepressed speB expression, suggesting that apo-RopB is a transcriptional repressor of speB Up-regulation of PepO in the covS mutant degraded SIP, resulting in the down-regulation of speB We demonstrate that deleting ropB in the covS mutant derepressed the speB expression, suggesting that the speB repression in this mutant was mediated not only by PepO-dependent SIP degradation but also by apo-RopB. These findings reveal a crosstalk between the CovR/CovS and RopB-SIP systems and redefine the role of RopB in regulating speB expression in group A Streptococcus.
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Affiliation(s)
- Chuan Chiang-Ni
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Yan-Wen Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Kai-Lin Chen
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Jian-Xian Jiang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yong-An Shi
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Yun Hsu
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Ywan M Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chih-Ho Lai
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
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Plainvert C, Rosinski-Chupin I, Weckel A, Lambert C, Touak G, Sauvage E, Poyart C, Glaser P, Fouet A. A Novel CovS Variant Harbored by a Colonization Strain Reduces Streptococcus pyogenes Virulence. J Bacteriol 2023; 205:e0003923. [PMID: 36920220 PMCID: PMC10127592 DOI: 10.1128/jb.00039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/16/2023] [Indexed: 03/16/2023] Open
Abstract
Streptococcus pyogenes, also known as group A Streptococcus, causes a wide variety of diseases ranging from mild noninvasive to severe invasive infections. To identify possible causes of colonization-to-invasive switches, we determined the genomic sequences of 10 isolates from five pairs each composed of an invasive strain and a carriage strain originating from five infectious clusters. Among them, one pair displayed a single-nucleotide difference in covS, encoding the sensor histidine kinase of the two-component CovRS system that controls the expression of 15% of the genome. In contrast to previously described cases where the invasive strains harbor nonfunctional CovS proteins, the carriage strain possessed the mutation covST115C, leading to the replacement of the tyrosine at position 39 by a histidine. The CovSY39H mutation affected the expression of the genes from the CovR regulon in a unique fashion. Genes usually overexpressed in covS mutant strains were underexpressed and vice versa. Furthermore, the covS mutant strain barely responded to the addition of the CovS-signaling compounds Mg2+ and LL-37. The variations in the accumulation of two virulence factors paralleled the transcription modifications. In addition, the covST115C mutant strain showed less survival than its wild-type counterpart in murine macrophages. Finally, in two murine models of infection, the covS mutant strain was less virulent than the wild-type strain. Our study suggests that the CovSY39H protein compromises CovS phosphatase activity and that this yields a noninvasive strain. IMPORTANCE Streptococcus pyogenes, also known as group A Streptococcus, causes a wide variety of diseases, leading to 517,000 deaths yearly. The two-component CovRS system, which responds to MgCl2 and the antimicrobial peptide LL-37, controls the expression of 15% of the genome. Invasive strains may harbor nonfunctional CovS sensor proteins that lead to the derepression of most virulence genes. We isolated a colonization strain that harbors a novel covS mutation. This mutant strain harbored a transcriptome profile opposite that of other covS mutant strains, barely responded to environmental signals, and was less virulent than the wild-type strain. This supports the importance of the derepression of the expression of most virulence genes, via mutations that impact the phosphorylation of the regulator CovR, for favoring S. pyogenes invasive infections.
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Affiliation(s)
- Céline Plainvert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Isabelle Rosinski-Chupin
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Antonin Weckel
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Clara Lambert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Gérald Touak
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Elisabeth Sauvage
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Claire Poyart
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
| | - Philippe Glaser
- Institut Pasteur, Ecologie et Evolution de la Résistance aux Antibiotiques, UMR3525, Paris, France
| | - Agnès Fouet
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
- Service de Bactériologie, CNR des Streptocoques, Hôpitaux Universitaires Paris Centre, Paris, France
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The CovRS Environmental Sensor Directly Controls the ComRS Signaling System To Orchestrate Competence Bimodality in Salivarius Streptococci. mBio 2022; 13:e0312521. [PMID: 35089064 PMCID: PMC8725580 DOI: 10.1128/mbio.03125-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In bacteria, phenotypic heterogeneity in an isogenic population compensates for the lack of genetic diversity and allows concomitant multiple survival strategies when choosing only one is too risky. This powerful tactic is exploited for competence development in streptococci where only a subset of the community triggers the pheromone signaling system ComR-ComS, resulting in a bimodal activation. However, the regulatory cascade and the underlying mechanisms of this puzzling behavior remained partially understood. Here, we show that CovRS, a well-described virulence regulatory system in pathogenic streptococci, directly controls the ComRS system to generate bimodality in the gut commensal Streptococcus salivarius and the closely related species Streptococcus thermophilus. Using single-cell analysis of fluorescent reporter strains together with regulatory mutants, we revealed that the intracellular concentration of ComR determines the proportion of competent cells in the population. We also showed that this bimodal activation requires a functional positive-feedback loop acting on ComS production, as well as its exportation and reinternalization via dedicated permeases. As the intracellular ComR concentration is critical in this process, we hypothesized that an environmental sensor could control its abundance. We systematically inactivated all two-component systems and identified CovRS as a direct repression system of comR expression. Notably, we showed that the system transduces its negative regulation through CovR binding to multiple sites in the comR promoter region. Since CovRS integrates environmental stimuli, we suggest that it is the missing piece of the puzzle that connects environmental conditions to (bimodal) competence activation in salivarius streptococci. IMPORTANCE Combining production of antibacterial compounds and uptake of DNA material released by dead cells, competence is one of the most efficient survival strategies in streptococci. Yet, this powerful tactic is energy consuming and reprograms the metabolism to such an extent that cell proliferation is transiently impaired. To circumvent this drawback, competence activation is restricted to a subpopulation, a process known as bimodality. In this work, we explored this phenomenon in salivarius streptococci and elucidated the molecular mechanisms governing cell fate. We also show that an environmental sensor controlling virulence in pathogenic streptococci is diverted to control competence in commensal streptococci. Together, those results showcase how bacteria can sense and transmit external stimuli to complex communication devices for fine-tuning collective behaviors.
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Horstmann N, Myers KS, Tran CN, Flores AR, Shelburne III SA. CovS inactivation reduces CovR promoter binding at diverse virulence factor encoding genes in group A Streptococcus. PLoS Pathog 2022; 18:e1010341. [PMID: 35180278 PMCID: PMC8893699 DOI: 10.1371/journal.ppat.1010341] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/03/2022] [Accepted: 02/04/2022] [Indexed: 11/18/2022] Open
Abstract
The control of virulence gene regulator (CovR), also called caspsule synthesis regulator (CsrR), is critical to how the major human pathogen group A Streptococcus fine-tunes virulence factor production. CovR phosphorylation (CovR~P) levels are determined by its cognate sensor kinase CovS, and functional abrogating mutations in CovS can occur in invasive GAS isolates leading to hypervirulence. Presently, the mechanism of CovR-DNA binding specificity is unclear, and the impact of CovS inactivation on global CovR binding has not been assessed. Thus, we performed CovR chromatin immunoprecipitation sequencing (ChIP-seq) analysis in the emm1 strain MGAS2221 and its CovS kinase deficient derivative strain 2221-CovS-E281A. We identified that CovR bound in the promoter regions of nearly all virulence factor encoding genes in the CovR regulon. Additionally, direct CovR binding was observed for numerous genes encoding proteins involved in amino acid metabolism, but we found limited direct CovR binding to genes encoding other transcriptional regulators. The consensus sequence AATRANAAAARVABTAAA was present in the promoters of genes directly regulated by CovR, and mutations of highly conserved positions within this motif relieved CovR repression of the hasA and MGAS2221_0187 promoters. Analysis of strain 2221-CovS-E281A revealed that binding of CovR at repressed, but not activated, promoters is highly dependent on CovR~P state. CovR repressed virulence factor encoding genes could be grouped dependent on how CovR~P dependent variation in DNA binding correlated with gene transcript levels. Taken together, the data show that CovR repression of virulence factor encoding genes is primarily direct in nature, involves binding to a newly-identified DNA binding motif, and is relieved by CovS inactivation. These data provide new mechanistic insights into one of the most important bacterial virulence regulators and allow for subsequent focused investigations into how CovR-DNA interaction at directly controlled promoters impacts GAS pathogenesis. Tight regulation of virulence factor production is a critical, but poorly understood aspect of bacterial pathogenesis. The OmpR/PhoB family member control of virulence regulator (CovR) is the master virulence factor controller in group A Streptococcus (GAS), a bacterium which commonly causes a diverse array of human infections. Mutations in the cognate kinase of CovR, CovS, are commonly observed among invasive GAS isolates, but the functional impact of CovS on global CovR function is unknown. Herein, we defined CovR global DNA binding locations, identified a consensus CovR binding motif, and determined how inactivation of the CovR cognate sensor kinase, CovS, impacts CovR-DNA interaction. Our findings show that CovR-repressed virulence factor encoding genes are directly regulated by CovR and that CovS inactivation markedly reduces CovR binding at CovR-repressed promoters. Given the widespread nature of CovR homologues in streptococci and other Gram-positive pathogens, these findings extend understanding of mechanisms by which OmpR/PhoB family members impact the ability of bacteria to cause serious infections.
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Affiliation(s)
- Nicola Horstmann
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Kevin S. Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chau Nguyen Tran
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Anthony R. Flores
- Center for Antimicrobial Resistance and Microbial Genomics McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Samuel A. Shelburne III
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- * E-mail:
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9
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Mazzuoli MV, Daunesse M, Varet H, Rosinski-Chupin I, Legendre R, Sismeiro O, Gominet M, Kaminski PA, Glaser P, Chica C, Trieu-Cuot P, Firon A. The CovR regulatory network drives the evolution of Group B Streptococcus virulence. PLoS Genet 2021; 17:e1009761. [PMID: 34491998 PMCID: PMC8448333 DOI: 10.1371/journal.pgen.1009761] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/17/2021] [Accepted: 08/09/2021] [Indexed: 01/31/2023] Open
Abstract
Virulence of the neonatal pathogen Group B Streptococcus is under the control of the master regulator CovR. Inactivation of CovR is associated with large-scale transcriptome remodeling and impairs almost every step of the interaction between the pathogen and the host. However, transcriptome analyses suggested a plasticity of the CovR signaling pathway in clinical isolates leading to phenotypic heterogeneity in the bacterial population. In this study, we characterized the CovR regulatory network in a strain representative of the CC-17 hypervirulent lineage responsible of the majority of neonatal meningitis. Transcriptome and genome-wide binding analysis reveal the architecture of the CovR network characterized by the direct repression of a large array of virulence-associated genes and the extent of co-regulation at specific loci. Comparative functional analysis of the signaling network links strain-specificities to the regulation of the pan-genome, including the two specific hypervirulent adhesins and horizontally acquired genes, to mutations in CovR-regulated promoters, and to variability in CovR activation by phosphorylation. This regulatory adaptation occurs at the level of genes, promoters, and of CovR itself, and allows to globally reshape the expression of virulence genes. Overall, our results reveal the direct, coordinated, and strain-specific regulation of virulence genes by the master regulator CovR and suggest that the intra-species evolution of the signaling network is as important as the expression of specific virulence factors in the emergence of clone associated with specific diseases. Streptococcus agalactiae, commonly known as the Group B Streptococcus (GBS), is a commensal bacterium of the intestinal and vaginal tracts found in approximately 30% of healthy adults. However, GBS is also an opportunistic pathogen and the leading cause of neonatal invasive infections. Epidemiologic data have identified a particular GBS clone, designated the CC-17 hypervirulent clonal complex, as responsible for the overwhelming majority of neonatal meningitis. The hypervirulence of CC-17 has been linked to the expression of two specific surface proteins increasing their abilities to cross epithelial and endothelial barriers. In this study, we characterized the role of the major regulator of virulence gene expression, the CovR response regulator, in a representative hypervirulent strain. Transcriptome and genome-wide binding analysis reveal the architecture of the CovR signaling network characterized by the direct repression of a large array of virulence-associated genes, including the specific hypervirulent adhesins. Comparative analysis in a non-CC-17 wild type strain demonstrates a high level of plasticity of the regulatory network, allowing to globally reshape pathogen-host interaction. Overall, our results suggest that the intra-species evolution of the regulatory network is an important factor in the emergence of GBS clones associated with specific pathologies.
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Affiliation(s)
- Maria-Vittoria Mazzuoli
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- Sorbonne Paris Cité, Université de Paris, Paris, France
| | - Maëlle Daunesse
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Hugo Varet
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Isabelle Rosinski-Chupin
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | - Rachel Legendre
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Odile Sismeiro
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Myriam Gominet
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Pierre Alexandre Kaminski
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Philippe Glaser
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | - Claudia Chica
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Patrick Trieu-Cuot
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Arnaud Firon
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- * E-mail:
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