1
|
Oh MW, Lin J, Chong SY, Lew SQ, Alam T, Lau GW. Time-resolved RNA-seq analysis to unravel the in vivo competence induction by Streptococcus pneumoniae during pneumonia-derived sepsis. Microbiol Spectr 2024; 12:e0305023. [PMID: 38305162 PMCID: PMC10913500 DOI: 10.1128/spectrum.03050-23] [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: 08/08/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Competence development in Streptococcus pneumoniae (pneumococcus) is tightly intertwined with virulence. In addition to genes encoding genetic transformation machinery, the competence regulon also regulates the expression of allolytic factors, bacteriocins, and cytotoxins. Pneumococcal competence system has been extensively interrogated in vitro where the short transient competent state upregulates the expression of three distinct phases of "early," "late," and "delayed" genes. Recently, we have demonstrated that the pneumococcal competent state develops naturally in mouse models of pneumonia-derived sepsis. To unravel the underlying adaptive mechanisms driving the development of the competent state, we conducted a time-resolved transcriptomic analysis guided by the spatiotemporal live in vivo imaging system of competence induction during pneumonia-derived sepsis. Mouse lungs infected by the serotype 2 strain D39 expressing a competent state-specific reporter gene (D39-ssbB-luc) were subjected to RNA sequencing guided by monitoring the competence development at 0, 12, 24, and, at the moribund state, >40 hours post-infection (hpi). Transcriptomic analysis revealed that the competence-specific gene expression patterns in vivo were distinct from those under in vitro conditions. There was significant upregulation of early, late, and some delayed phase competence-specific genes as early as 12 hpi, suggesting that the pneumococcal competence regulon is important for adaptation to the lung environment. Additionally, members of the histidine triad (pht) gene family were sharply upregulated at 12 hpi followed by a steep decline throughout the rest of the infection cycle, suggesting that Pht proteins participate in the early adaptation to the lung environment. Further analysis revealed that Pht proteins execute a metal ion-dependent regulatory role in competence induction.IMPORTANCEThe induction of pneumococcal competence for genetic transformation has been extensively studied in vitro but poorly understood during lung infection. We utilized a combination of live imaging and RNA sequencing to monitor the development of a competent state during acute pneumonia. Upregulation of competence-specific genes was observed as early as 12 hour post-infection, suggesting that the pneumococcal competence regulon plays an important role in adapting pneumococcus to the stressful lung environment. Among others, we report novel finding that the pneumococcal histidine triad (pht) family of genes participates in the adaptation to the lung environment and regulates pneumococcal competence induction.
Collapse
Affiliation(s)
- Myung Whan Oh
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jingjun Lin
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Sook Yin Chong
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shi Qian Lew
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Tauqeer Alam
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Gee W. Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| |
Collapse
|
2
|
Euba B, Gil-Campillo C, Asensio-López J, López-López N, Sen-Kilic E, Díez-Martínez R, Burgui S, Barbier M, Garmendia J. In Vivo Genome-Wide Gene Expression Profiling Reveals That Haemophilus influenzae Purine Synthesis Pathway Benefits Its Infectivity within the Airways. Microbiol Spectr 2023; 11:e0082323. [PMID: 37195232 PMCID: PMC10269889 DOI: 10.1128/spectrum.00823-23] [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: 02/23/2023] [Accepted: 04/27/2023] [Indexed: 05/18/2023] Open
Abstract
Haemophilus influenzae is a human-adapted bacterial pathogen that causes airway infections. Bacterial and host elements associated with the fitness of H. influenzae within the host lung are not well understood. Here, we exploited the strength of in vivo-omic analyses to study host-microbe interactions during infection. We used in vivo transcriptome sequencing (RNA-seq) for genome-wide profiling of both host and bacterial gene expression during mouse lung infection. Profiling of murine lung gene expression upon infection showed upregulation of lung inflammatory response and ribosomal organization genes, and downregulation of cell adhesion and cytoskeleton genes. Transcriptomic analysis of bacteria recovered from bronchoalveolar lavage fluid samples from infected mice showed a significant metabolic rewiring during infection, which was highly different from that obtained upon bacterial in vitro growth in an artificial sputum medium suitable for H. influenzae. In vivo RNA-seq revealed upregulation of bacterial de novo purine biosynthesis, genes involved in non-aromatic amino acid biosynthesis, and part of the natural competence machinery. In contrast, the expression of genes involved in fatty acid and cell wall synthesis and lipooligosaccharide decoration was downregulated. Correlations between upregulated gene expression and mutant attenuation in vivo were established, as observed upon purH gene inactivation leading to purine auxotrophy. Likewise, the purine analogs 6-thioguanine and 6-mercaptopurine reduced H. influenzae viability in a dose-dependent manner. These data expand our understanding of H. influenzae requirements during infection. In particular, H. influenzae exploits purine nucleotide synthesis as a fitness determinant, raising the possibility of purine synthesis as an anti-H. influenzae target. IMPORTANCE In vivo-omic strategies offer great opportunities for increased understanding of host-pathogen interplay and for identification of therapeutic targets. Here, using transcriptome sequencing, we profiled host and pathogen gene expression during H. influenzae infection within the murine airways. Lung pro-inflammatory gene expression reprogramming was observed. Moreover, we uncovered bacterial metabolic requirements during infection. In particular, we identified purine synthesis as a key player, highlighting that H. influenzae may face restrictions in purine nucleotide availability within the host airways. Therefore, blocking this biosynthetic process may have therapeutic potential, as supported by the observed inhibitory effect of 6-thioguanine and 6-mercaptopurine on H. influenzae growth. Together, we present key outcomes and challenges for implementing in vivo-omics in bacterial airway pathogenesis. Our findings provide metabolic insights into H. influenzae infection biology, raising the possibility of purine synthesis as an anti-H. influenzae target and of purine analog repurposing as an antimicrobial strategy against this pathogen.
Collapse
Affiliation(s)
- Begoña Euba
- Instituto de Agrobiotecnología (IDAB), Consejo Superior de Investigaciones Científicas (CSIC)-Gobierno de Navarra, Mutilva, Spain
| | - Celia Gil-Campillo
- Instituto de Agrobiotecnología (IDAB), Consejo Superior de Investigaciones Científicas (CSIC)-Gobierno de Navarra, Mutilva, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Javier Asensio-López
- Instituto de Agrobiotecnología (IDAB), Consejo Superior de Investigaciones Científicas (CSIC)-Gobierno de Navarra, Mutilva, Spain
- Asociación de la Industria Navarra (AIN)-Gobierno de Navarra, Cordovilla, Spain
| | - Nahikari López-López
- Instituto de Agrobiotecnología (IDAB), Consejo Superior de Investigaciones Científicas (CSIC)-Gobierno de Navarra, Mutilva, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Emel Sen-Kilic
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, West Virginia, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | | | - Saioa Burgui
- Asociación de la Industria Navarra (AIN)-Gobierno de Navarra, Cordovilla, Spain
| | - Mariette Barbier
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, West Virginia, USA
- Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - Junkal Garmendia
- Instituto de Agrobiotecnología (IDAB), Consejo Superior de Investigaciones Científicas (CSIC)-Gobierno de Navarra, Mutilva, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Conexión Nanomedicina-CSIC, Madrid, Spain
| |
Collapse
|
3
|
Zafar MA, Costa-Terryl A, Young TM. The Two-Component System YesMN Promotes Pneumococcal Host-to-Host Transmission and Regulates Genes Involved in Zinc Homeostasis. Infect Immun 2023; 91:e0037522. [PMID: 36537790 PMCID: PMC9872629 DOI: 10.1128/iai.00375-22] [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: 08/25/2022] [Accepted: 11/27/2022] [Indexed: 01/25/2023] Open
Abstract
The ability to sense and respond rapidly to the dynamic environment of the upper respiratory tract (URT) makes Streptococcus pneumoniae (Spn) a highly successful human pathogen. Two-component systems (TCSs) of Spn sense and respond to multiple signals it encounters allowing Spn to adapt and thrive in various host sites. Spn TCS have been implicated in their ability to promote pneumococcal colonization of the URT and virulence. As the disease state can be a dead-end for a pathogen, we considered whether TCS would contribute to pneumococcal transmission. Herein, we determined the role of YesMN, an understudied TCS of Spn, and observe that YesMN contributes toward pneumococcal shedding and transmission but is not essential for colonization. The YesMN regulon includes genes involved in zinc homeostasis and glycan metabolism, which are upregulated during reduced zinc availability in a YesMN-dependent fashion. Thus, we identified the YesMN regulon and a potential molecular signal it senses that lead to the activation of genes involved in zinc homeostasis and glycan metabolism. Furthermore, in contrast to Spn monoinfection, we demonstrate that YesMN is critical for high pneumococcal density in the URT during influenza A virus (IAV) coinfection. We attribute reduced colonization of the yesMN mutant possibly due to increased association with and clearance by the mucus covering the URT epithelial surface. Thus, our results highlight the dynamic interactions that occur between Spn and IAV in the URT, and the role that TCSs play in modulation of these interactions.
Collapse
Affiliation(s)
- M. Ammar Zafar
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Alicia Costa-Terryl
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Taylor M. Young
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| |
Collapse
|
4
|
Jim KK, Aprianto R, Koning R, Domenech A, Kurushima J, van de Beek D, Vandenbroucke-Grauls CMJE, Bitter W, Veening JW. Pneumolysin promotes host cell necroptosis and bacterial competence during pneumococcal meningitis as shown by whole-animal dual RNA-seq. Cell Rep 2022; 41:111851. [PMID: 36543127 PMCID: PMC9794515 DOI: 10.1016/j.celrep.2022.111851] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/16/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Pneumolysin is a major virulence factor of Streptococcus pneumoniae that plays a key role in interaction with the host during invasive disease. How pneumolysin influences these dynamics between host and pathogen interaction during early phase of central nervous system infection in pneumococcal meningitis remains unclear. Using a whole-animal in vivo dual RNA sequencing (RNA-seq) approach, we identify pneumolysin-specific transcriptional responses in both S. pneumoniae and zebrafish (Danio rerio) during early pneumococcal meningitis. By functional enrichment analysis, we identify host pathways known to be activated by pneumolysin and discover the importance of necroptosis for host survival. Inhibition of this pathway using the drug GSK'872 increases host mortality during pneumococcal meningitis. On the pathogen's side, we show that pneumolysin-dependent competence activation is crucial for intra-host replication and virulence. Altogether, this study provides new insights into pneumolysin-specific transcriptional responses and identifies key pathways involved in pneumococcal meningitis.
Collapse
Affiliation(s)
- Kin Ki Jim
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands; Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Rieza Aprianto
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Rutger Koning
- Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Arnau Domenech
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Jun Kurushima
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Diederik van de Beek
- Amsterdam UMC Location University of Amsterdam, Department of Neurology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Christina M J E Vandenbroucke-Grauls
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands
| | - Wilbert Bitter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Department of Medical Microbiology and Infection Prevention, De Boelelaan 1117, Amsterdam, the Netherlands; Amsterdam Institute for Infection and Immunity, Amsterdam, the Netherlands; Section of Molecular Microbiology, Amsterdam Institute for Molecules, Medicines and Systems, VU University Amsterdam, 1081 Amsterdam, the Netherlands
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland.
| |
Collapse
|
5
|
Audshasai T, Coles JA, Panagiotou S, Khandaker S, Scales HE, Kjos M, Baltazar M, Vignau J, Brewer JM, Kadioglu A, Yang M. Streptococcus pneumoniae Rapidly Translocate from the Nasopharynx through the Cribriform Plate to Invade the Outer Meninges. mBio 2022; 13:e0102422. [PMID: 35924840 PMCID: PMC9426477 DOI: 10.1128/mbio.01024-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/05/2022] [Indexed: 11/20/2022] Open
Abstract
The entry routes and translocation mechanisms of microorganisms or particulate materials into the central nervous system remain obscure We report here that Streptococcus pneumoniae (pneumococcus), or polystyrene microspheres of similar size, appear in the meninges of the dorsal cortex of mice within minutes of inhaled delivery. Recovery of viable bacteria from dissected tissue and fluorescence microscopy show that up to at least 72 h, pneumococci and microspheres were predominantly found in the outer of the two meninges: the pachymeninx. No pneumococci were found in blood or cerebrospinal fluid. Intravital imaging through the skull, aligned with flow cytometry showed recruitment and activation of LysM+ cells in the dorsal pachymeninx at 5 and 10 hours following intranasal infection. Imaging of the cribriform plate suggested that both pneumococci and microspheres entered through the foramina via an inward flow of fluid connecting the nose to the pachymeninx. Our findings bring new insight into the varied mechanisms of pneumococcal invasion of the central nervous system, but they are also pertinent to the delivery of drugs to the brain and the entry of airborne particulate matter into the cranium. IMPORTANCE Using two-photon imaging, we show that pneumococci translocate from the nasopharynx to the dorsal meninges of a mouse in the absence of any bacteria found in blood or cerebrospinal fluid. Strikingly, this takes place within minutes of inhaled delivery of pneumococci, suggesting the existence of an inward flow of fluid connecting the nasopharynx to the meninges, rather than a receptor-mediated mechanism. We also show that this process is size dependent, as microspheres of the same size as pneumococci can translocate along the same pathway, while larger size microspheres cannot. Furthermore, we describe the host response to invasion of the outer meninges. Our study provides a completely new insight into the key initial events that occur during the translocation of pneumococci directly from the nasal cavity to the meninges, with relevance to the development of intranasal drug delivery systems and the investigations of brain damage caused by inhaled air pollutants.
Collapse
Affiliation(s)
- Teerawit Audshasai
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
- Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Jonathan A. Coles
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Stavros Panagiotou
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Shadia Khandaker
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Hannah E. Scales
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Murielle Baltazar
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Julie Vignau
- Centre de Recherche en Cancérologie et Immunologie Nantes Angers, Université de Nantes, Nantes, France
| | - James M. Brewer
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Aras Kadioglu
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Marie Yang
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| |
Collapse
|
6
|
Forrester S, Goundry A, Dias BT, Leal-Calvo T, Moraes MO, Kaye PM, Mottram JC, Lima APCA. Tissue Specific Dual RNA-Seq Defines Host-Parasite Interplay in Murine Visceral Leishmaniasis Caused by Leishmania donovani and Leishmania infantum. Microbiol Spectr 2022; 10:e0067922. [PMID: 35384718 PMCID: PMC9045295 DOI: 10.1128/spectrum.00679-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 01/22/2023] Open
Abstract
Visceral leishmaniasis is associated with hepato-splenomegaly and altered immune and hematological parameters in both preclinical animal models and humans. We studied mouse experimental visceral leishmaniasis caused by Leishmania infantum and Leishmania donovani in BALB/c mice using dual RNA-seq to investigate the transcriptional response of host and parasite in liver and spleen. We identified only 4 species-specific parasite expressed genes (SSPEGs; log2FC >1, FDR <0.05) in the infected spleen, and none in the infected liver. For the host transcriptome, we found 789 differentially expressed genes (DEGs; log2FC >1, FDR <0.05) in the spleen that were common to both infections, with IFNγ signaling and complement and coagulation cascade pathways highly enriched, and an additional 286 and 186 DEGs that were selective to L. donovani and L. infantum infection, respectively. Among those, there were network interactions between genes of amino acid metabolism and PPAR signaling in L. donovani infection and increased IL1β and positive regulation of fatty acid transport in L. infantum infection, although no pathway enrichment was observed. In the liver, there were 1,939 DEGs in mice infected with either L. infantum or L. donovani in comparison to uninfected mice, and the most enriched pathways were IFNγ signaling, neutrophil mediated immunity, complement and coagulation, cytokine-chemokine responses, and hemostasis. Additionally, 221 DEGs were selective in L. donovani and 429 DEGs in L. infantum infections. These data show that the host response for these two visceral leishmaniasis infection models is broadly similar, and ∼10% of host DEGs vary in infections with either parasite species. IMPORTANCE Visceral leishmaniasis (VL) is caused by two species of Leishmania parasites, L. donovani in the Old World and L. infantum in the New World and countries bordering the Mediterranean. Although cardinal features such as hepato-splenomegaly and alterations in blood and immune function are evident, clinical presentation may vary by geography, with for example severe bleeding often associated with VL in Brazil. Although animal models of both L. donovani and L. infantum have been widely used to study disease pathogenesis, a direct side-by-side comparison of how these parasites species impact the infected host and/or how they might respond to the stresses of mammalian infection has not been previously reported. Identifying common and distinct pathways to pathogenesis will be important to ensure that new therapeutic or prophylactic approaches will be applicable across all forms of VL.
Collapse
Affiliation(s)
- Sarah Forrester
- York Biomedical Research Institute, Department of Biology, University of York, York, England, United Kingdom
| | - Amy Goundry
- York Biomedical Research Institute, Department of Biology, University of York, York, England, United Kingdom
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruna Torres Dias
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Paul M. Kaye
- York Biomedical Research Institute, Hull York Medical School, University of York, York, England, United Kingdom
| | - Jeremy C. Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, England, United Kingdom
| | - Ana Paula C. A. Lima
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
7
|
Agnew HN, Brazel EB, Tikhomirova A, van der Linden M, McLean KT, Paton JC, Trappetti C. Streptococcus pneumoniae Strains Isolated From a Single Pediatric Patient Display Distinct Phenotypes. Front Cell Infect Microbiol 2022; 12:866259. [PMID: 35433506 PMCID: PMC9008571 DOI: 10.3389/fcimb.2022.866259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/08/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of bacterial paediatric meningitis after the neonatal period worldwide, but the bacterial factors and pathophysiology that drive pneumococcal meningitis are not fully understood. In this work, we have identified differences in raffinose utilization by S. pneumoniae isolates of identical serotype and sequence type from the blood and cerebrospinal fluid (CSF) of a single pediatric patient with meningitis. The blood isolate displayed defective raffinose metabolism, reduced transcription of the raffinose utilization pathway genes, and an inability to grow in vitro when raffinose was the sole carbon source. The fitness of these strains was then assessed using a murine intranasal infection model. Compared with the CSF isolate, mice infected with the blood isolate displayed higher bacterial numbers in the nose, but this strain was unable to invade the ears of infected mice. A premature stop codon was identified in the aga gene in the raffinose locus, suggesting that this protein likely displays impaired alpha-galactosidase activity. These closely related strains were assessed by Illumina sequencing, which did not identify any single nucleotide polymorphisms (SNPs) between the two strains. However, these wider genomic analyses identified the presence of an alternative alpha-galactosidase gene that appeared to display altered sequence coverage between the strains, which may account for the observed differences in raffinose metabolic capacity. Together, these studies support previous findings that raffinose utilization capacity contributes to disease progression, and provide insight into a possible alternative means by which perturbation of this pathway may influence the behavior of pneumococci in the host environment, particularly in meningitis.
Collapse
Affiliation(s)
- Hannah N. Agnew
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
| | - Erin B. Brazel
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
| | - Alexandra Tikhomirova
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
| | - Mark van der Linden
- German National Reference Center for Streptoccocci, University Hospital Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, Aachen, Germany
| | - Kimberley T. McLean
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
| | - James C. Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
- *Correspondence: Claudia Trappetti, ; James C. Paton,
| | - Claudia Trappetti
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SAAustralia
- *Correspondence: Claudia Trappetti, ; James C. Paton,
| |
Collapse
|
8
|
The Role of luxS in the Middle Ear Streptococcus pneumoniae Isolate 947. Pathogens 2022; 11:pathogens11020216. [PMID: 35215159 PMCID: PMC8877971 DOI: 10.3390/pathogens11020216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 02/04/2023] Open
Abstract
The LuxS protein, encoded by luxS, is required for the production of autoinducer 2 (AI-2) in Streptococcus pneumoniae. The AI-2 molecule serves as a quorum sensing signal, and thus regulates cellular processes such as carbohydrate utilisation and biofilm formation, as well as impacting virulence. The role of luxS in S. pneumoniae biology and lifestyle has been predominantly assessed in the laboratory strain D39. However, as biofilm formation, which is regulated by luxS, is critical for the ability of S. pneumoniae to cause otitis media, we investigated the role of luxS in a middle ear isolate, strain 947. Our results identified luxS to have a role in prevention of S. pneumoniae transition from colonisation of the nasopharynx to the ear, and in facilitating adherence to host epithelial cells.
Collapse
|
9
|
Look Who's Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis. Int J Mol Sci 2022; 23:ijms23020860. [PMID: 35055041 PMCID: PMC8775791 DOI: 10.3390/ijms23020860] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 02/04/2023] Open
Abstract
Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.
Collapse
|
10
|
Babb R, Doyle CR, Pirofski LA. Isolation and Characterization of Human Monoclonal Antibodies to Pneumococcal Capsular Polysaccharide 3. Microbiol Spectr 2021; 9:e0144621. [PMID: 34756090 PMCID: PMC8579928 DOI: 10.1128/spectrum.01446-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 10/17/2021] [Indexed: 11/20/2022] Open
Abstract
The current pneumococcal capsular polysaccharide (PPS) conjugate vaccine (PCV13) is less effective against Streptococcus pneumoniae serotype 3 (ST3), which remains a major cause of pneumococcal disease and mortality. Therefore, dissecting structure-function relationships of human ST3 pneumococcal capsular polysaccharide (PPS3) antibodies may reveal characteristics of protective antibodies. Using flow cytometry, we isolated PPS3-binding memory B cells from pneumococcal vaccine recipients and generated seven PPS3-specific human monoclonal antibodies (humAbs). Five humAbs displayed ST3 opsonophagocytic activity, four induced ST3 agglutination in vitro, and four mediated both activities. Two humAbs, namely, C10 and C27, that used the same variable heavy (VH) and light (VL) chain domains (VH3-9*01/VL2-14*03) both altered ST3 gene expression in vitro; however, C10 had fewer VL somatic mutations, higher PPS3 affinity, and promoted in vitro ST3 opsonophagocytic and agglutinating activity, whereas C27 did not. In C57BL/6 mice, both humAbs reduced nasopharyngeal colonization with ST3 A66 and a clinical strain, B2, and prolonged survival following lethal A66 intraperitoneal infection, but only C10 protected against lethal intranasal infection with the clinical strain. After performing VL swaps, C10VH/C27VL exhibited reduced ST3 binding and agglutination, but C27VH/C10VL binding was unchanged. However, both humAbs lost the ability to reduce colonization in vivo when their light chains were replaced. Our findings associate the ability of PPS3-specific humAbs to reduce colonization with ST3 agglutination and opsonophagocytic activity, and reveal an unexpected role for the VL in their functional activity in vitro and in vivo. These findings also provide insights that may inform antibody-based therapy and identification of surrogates of vaccine efficacy against ST3. IMPORTANCE Despite the global success of vaccination with pneumococcal conjugate vaccines, serotype 3 (ST3) pneumococcus remains a leading cause of morbidity and mortality. In comparison to other vaccine-included serotypes, the ST3 pneumococcal capsular polysaccharide (PPS3) induces a weaker opsonophagocytic response, which is considered a correlate of vaccine efficacy. Previous studies of mouse PPS3 monoclonal antibodies identified ST3 agglutination as a correlate of reduced ST3 nasopharyngeal colonization in mice; however, neither the agglutinating ability of human vaccine-elicited PPS3 antibodies nor their ability to prevent experimental murine nasopharyngeal colonization has been studied. We generated and analyzed the functional and in vivo efficacy of human vaccine-elicited PPS3 monoclonal antibodies and found that ST3 agglutination associated with antibody affinity, protection in vivo, and limited somatic mutations in the light chain variable region. These findings provide new insights that may inform the development of antibody-based therapies and next-generation vaccines for ST3.
Collapse
Affiliation(s)
- Rachelle Babb
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA
| | | | - Liise-anne Pirofski
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA
| |
Collapse
|
11
|
Halder V, McDonnell B, Uthayakumar D, Usher J, Shapiro RS. Genetic interaction analysis in microbial pathogens: unravelling networks of pathogenesis, antimicrobial susceptibility and host interactions. FEMS Microbiol Rev 2021; 45:fuaa055. [PMID: 33145589 DOI: 10.1093/femsre/fuaa055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/16/2020] [Indexed: 12/13/2022] Open
Abstract
Genetic interaction (GI) analysis is a powerful genetic strategy that analyzes the fitness and phenotypes of single- and double-gene mutant cells in order to dissect the epistatic interactions between genes, categorize genes into biological pathways, and characterize genes of unknown function. GI analysis has been extensively employed in model organisms for foundational, systems-level assessment of the epistatic interactions between genes. More recently, GI analysis has been applied to microbial pathogens and has been instrumental for the study of clinically important infectious organisms. Here, we review recent advances in systems-level GI analysis of diverse microbial pathogens, including bacterial and fungal species. We focus on important applications of GI analysis across pathogens, including GI analysis as a means to decipher complex genetic networks regulating microbial virulence, antimicrobial drug resistance and host-pathogen dynamics, and GI analysis as an approach to uncover novel targets for combination antimicrobial therapeutics. Together, this review bridges our understanding of GI analysis and complex genetic networks, with applications to diverse microbial pathogens, to further our understanding of virulence, the use of antimicrobial therapeutics and host-pathogen interactions. .
Collapse
Affiliation(s)
- Viola Halder
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Brianna McDonnell
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Deeva Uthayakumar
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Jane Usher
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| |
Collapse
|
12
|
Abstract
Purpose of review Community-acquired bacterial meningitis is a continually changing disease. This review summarises both dynamic epidemiology and emerging data on pathogenesis. Updated clinical guidelines are discussed, new agents undergoing clinical trials intended to reduce secondary brain damage are presented. Recent findings Conjugate vaccines are effective against serotype/serogroup-specific meningitis but vaccine escape variants are rising in prevalence. Meningitis occurs when bacteria evade mucosal and circulating immune responses and invade the brain: directly, or across the blood–brain barrier. Tissue damage is caused when host genetic susceptibility is exploited by bacterial virulence. The classical clinical triad of fever, neck stiffness and headache has poor diagnostic sensitivity, all guidelines reflect the necessity for a low index of suspicion and early Lumbar puncture. Unnecessary cranial imaging causes diagnostic delays. cerebrospinal fluid (CSF) culture and PCR are diagnostic, direct next-generation sequencing of CSF may revolutionise diagnostics. Administration of early antibiotics is essential to improve survival. Dexamethasone partially mitigates central nervous system inflammation in high-income settings. New agents in clinical trials include C5 inhibitors and daptomycin, data are expected in 2025. Summary Clinicians must remain vigilant for bacterial meningitis. Constantly changing epidemiology and emerging pathogenesis data are increasing the understanding of meningitis. Prospects for better treatments are forthcoming.
Collapse
|
13
|
McCall LI. Quo vadis? Central Rules of Pathogen and Disease Tropism. Front Cell Infect Microbiol 2021; 11:640987. [PMID: 33718287 PMCID: PMC7947345 DOI: 10.3389/fcimb.2021.640987] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 01/18/2021] [Indexed: 12/12/2022] Open
Abstract
Understanding why certain people get sick and die while others recover or never become ill is a fundamental question in biomedical research. A key determinant of this process is pathogen and disease tropism: the locations that become infected (pathogen tropism), and the locations that become damaged (disease tropism). Identifying the factors that regulate tropism is essential to understand disease processes, but also to drive the development of new interventions. This review intersects research from across infectious diseases to define the central mediators of disease and pathogen tropism. This review also highlights methods of study, and translational implications. Overall, tropism is a central but under-appreciated aspect of infection pathogenesis which should be at the forefront when considering the development of new methods of intervention.
Collapse
Affiliation(s)
- Laura-Isobel McCall
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, United States
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States
- Stephenson Cancer Center, University of Oklahoma, Oklahoma City, OK, United States
- Laboratories of Molecular Anthropology and Microbiome Research, University of Oklahoma, Norman, OK, United States
| |
Collapse
|
14
|
Minhas V, Paton JC, Trappetti C. Sickly Sweet - How Sugar Utilization Impacts Pneumococcal Disease Progression. Trends Microbiol 2021; 29:768-771. [PMID: 33612397 DOI: 10.1016/j.tim.2021.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 10/22/2022]
Abstract
Streptococcus pneumoniae is a major human pathogen that can spread to multiple sites in the body. However, the mechanisms dictating disease spread are not well understood. Here we highlight the importance of carbohydrate utilization systems on pneumococcal disease, offering insight into how this pathogen causes a spectrum of disease.
Collapse
Affiliation(s)
- Vikrant Minhas
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, the University of Adelaide, Adelaide, 5005, Australia
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, the University of Adelaide, Adelaide, 5005, Australia.
| | - Claudia Trappetti
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, the University of Adelaide, Adelaide, 5005, Australia
| |
Collapse
|
15
|
Westermann AJ, Vogel J. Cross-species RNA-seq for deciphering host-microbe interactions. Nat Rev Genet 2021; 22:361-378. [PMID: 33597744 DOI: 10.1038/s41576-021-00326-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
The human body is constantly exposed to microorganisms, which entails manifold interactions between human cells and diverse commensal or pathogenic bacteria. The cellular states of the interacting cells are decisive for the outcome of these encounters such as whether bacterial virulence programmes and host defence or tolerance mechanisms are induced. This Review summarizes how next-generation RNA sequencing (RNA-seq) has become a primary technology to study host-microbe interactions with high resolution, improving our understanding of the physiological consequences and the mechanisms at play. We illustrate how the discriminatory power and sensitivity of RNA-seq helps to dissect increasingly complex cellular interactions in time and space down to the single-cell level. We also outline how future transcriptomics may answer currently open questions in host-microbe interactions and inform treatment schemes for microbial disorders.
Collapse
Affiliation(s)
- Alexander J Westermann
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany. .,Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany.
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany. .,Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany.
| |
Collapse
|
16
|
D'Mello A, Riegler AN, Martínez E, Beno SM, Ricketts TD, Foxman EF, Orihuela CJ, Tettelin H. An in vivo atlas of host-pathogen transcriptomes during Streptococcus pneumoniae colonization and disease. Proc Natl Acad Sci U S A 2020; 117:33507-33518. [PMID: 33318198 PMCID: PMC7777036 DOI: 10.1073/pnas.2010428117] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pneumoniae (Spn) colonizes the nasopharynx and can cause pneumonia. From the lungs it spreads to the bloodstream and causes organ damage. We characterized the in vivo Spn and mouse transcriptomes within the nasopharynx, lungs, blood, heart, and kidneys using three Spn strains. We identified Spn genes highly expressed at all anatomical sites and in an organ-specific manner; highly expressed genes were shown to have vital roles with knockout mutants. The in vivo bacterial transcriptome during colonization/disease was distinct from previously reported in vitro transcriptomes. Distinct Spn and host gene-expression profiles were observed during colonization and disease states, revealing specific genes/operons whereby Spn adapts to and influences host sites in vivo. We identified and experimentally verified host-defense pathways induced by Spn during invasive disease, including proinflammatory responses and the interferon response. These results shed light on the pathogenesis of Spn and identify therapeutic targets.
Collapse
Affiliation(s)
- Adonis D'Mello
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Ashleigh N Riegler
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Eriel Martínez
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Sarah M Beno
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Tiffany D Ricketts
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ellen F Foxman
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Carlos J Orihuela
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201;
| |
Collapse
|