1
|
Cools F, Delputte P, Cos P. The search for novel treatment strategies for Streptococcus pneumoniae infections. FEMS Microbiol Rev 2021; 45:6064299. [PMID: 33399826 PMCID: PMC8371276 DOI: 10.1093/femsre/fuaa072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 01/01/2021] [Indexed: 12/13/2022] Open
Abstract
This review provides an overview of the most important novel treatment strategies against Streptococcus pneumoniae infections published over the past 10 years. The pneumococcus causes the majority of community-acquired bacterial pneumonia cases, and it is one of the prime pathogens in bacterial meningitis. Over the last 10 years, extensive research has been conducted to prevent severe pneumococcal infections, with a major focus on (i) boosting the host immune system and (ii) discovering novel antibacterials. Boosting the immune system can be done in two ways, either by actively modulating host immunity, mostly through administration of selective antibodies, or by interfering with pneumococcal virulence factors, thereby supporting the host immune system to effectively overcome an infection. While several of such experimental therapies are promising, few have evolved to clinical trials. The discovery of novel antibacterials is hampered by the high research and development costs versus the relatively low revenues for the pharmaceutical industry. Nevertheless, novel enzymatic assays and target-based drug design, allow the identification of targets and the development of novel molecules to effectively treat this life-threatening pathogen.
Collapse
Affiliation(s)
- F Cools
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Delputte
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Cos
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| |
Collapse
|
2
|
Cools F, Triki D, Geerts N, Delputte P, Fourches D, Cos P. In vitro and in vivo Evaluation of in silico Predicted Pneumococcal UDPG:PP Inhibitors. Front Microbiol 2020; 11:1596. [PMID: 32760374 PMCID: PMC7373766 DOI: 10.3389/fmicb.2020.01596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/18/2020] [Indexed: 11/25/2022] Open
Abstract
Pneumonia, of which Streptococcus pneumoniae is the most common causative agent, is considered one of the three top leading causes of death worldwide. As seen in other bacterial species, antimicrobial resistance is on the rise for this pathogen. Therefore, there is a pressing need for novel antimicrobial strategies to combat these infections. Recently, uridine diphosphate glucose pyrophosphorylase (UDPG:PP) has been put forward as a potential drug target worth investigating. Moreover, earlier research demonstrated that streptococci lacking a functional galU gene (encoding for UDPG:PP) were characterized by significantly reduced in vitro and in vivo virulence. Therefore, in this study we evaluated the anti-virulence activity of potential UDPG:PP inhibitors. They were selected in silico using a tailor-made streptococcal homology model, based on earlier listerial research. While the compounds didn’t affect bacterial growth, nor affected in vitro adhesion to and phagocytosis in macrophages, the amount of polysaccharide capsule was significantly reduced after co-incubation with these inhibitors. Moreover, co-incubation proved to have a positive effect on survival in an in vivo Galleria mellonella larval infection model. Therefore, rather than targeting bacterial survival directly, these compounds proved to have an effect on streptococcal virulence by lowering the amount of polysaccharide and thereby probably boosting recognition of this pathogen by the innate immune system. While the compounds need adaptation to broaden their activity to more streptococcal strains rather than being strain-specific, this study consolidates UDPG:PP as a potential novel drug target.
Collapse
Affiliation(s)
- Freya Cools
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Dhoha Triki
- Department of Chemistry, Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States
| | - Nele Geerts
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Peter Delputte
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Denis Fourches
- Department of Chemistry, Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States
| | - Paul Cos
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| |
Collapse
|
3
|
Del Borrello G, Stocchero M, Giordano G, Pirillo P, Zanconato S, Da Dalt L, Carraro S, Esposito S, Baraldi E. New insights into pediatric community-acquired pneumonia gained from untargeted metabolomics: A preliminary study. Pediatr Pulmonol 2020; 55:418-425. [PMID: 31821737 PMCID: PMC7168041 DOI: 10.1002/ppul.24602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 12/02/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Available diagnostics often fail to distinguish viral from bacterial causes of pediatric community-acquired pneumonia (pCAP). Metabolomics, which aims at characterizing diseases based on their metabolic signatures, has been applied to expand pathophysiological understanding of many diseases. In this exploratory study, we used the untargeted metabolomic analysis to shed new light on the etiology of pCAP. METHODS Liquid chromatography coupled with mass spectrometry was used to quantify the metabolite content of urine samples collected from children hospitalized for CAP of pneumococcal or viral etiology, ascertained using a conservative algorithm combining microbiological and biochemical data. RESULTS Fifty-nine children with CAP were enrolled over 16 months. Pneumococcal and viral cases were distinguished by means of a multivariate model based on 93 metabolites, 20 of which were identified and considered as putative biomarkers. Among these, six metabolites belonged to the adrenal steroid synthesis and degradation pathway. CONCLUSIONS This preliminary study suggests that viral and pneumococcal pneumonia differently affect the systemic metabolome, with a stronger disruption of the adrenal steroid pathway in pneumococcal pneumonia. This finding may lead to the discovery of novel diagnostic biomarkers and bring us closer to personalized therapy for pCAP.
Collapse
Affiliation(s)
| | - Matteo Stocchero
- Department of Women's and Children's Health, University of Padova, Padova, Italy.,Institute of Pediatric Research (IRP), Fondazione Città della Speranza, Padova, Italy
| | - Giuseppe Giordano
- Department of Women's and Children's Health, University of Padova, Padova, Italy.,Institute of Pediatric Research (IRP), Fondazione Città della Speranza, Padova, Italy
| | - Paola Pirillo
- Department of Women's and Children's Health, University of Padova, Padova, Italy.,Institute of Pediatric Research (IRP), Fondazione Città della Speranza, Padova, Italy
| | - Stefania Zanconato
- Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Liviana Da Dalt
- Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Silvia Carraro
- Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Susanna Esposito
- Department of Surgical and Biomedical Sciences, Pediatric Clinic, University of Perugia, Perugia, Italy
| | - Eugenio Baraldi
- Department of Women's and Children's Health, University of Padova, Padova, Italy.,Institute of Pediatric Research (IRP), Fondazione Città della Speranza, Padova, Italy
| |
Collapse
|
4
|
Cools F, Torfs E, Aizawa J, Vanhoutte B, Maes L, Caljon G, Delputte P, Cappoen D, Cos P. Optimization and Characterization of a Galleria mellonella Larval Infection Model for Virulence Studies and the Evaluation of Therapeutics Against Streptococcus pneumoniae. Front Microbiol 2019; 10:311. [PMID: 30846978 PMCID: PMC6394149 DOI: 10.3389/fmicb.2019.00311] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/05/2019] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of bacterial pneumonia. Infection is linked to high morbidity and mortality rates and antibiotic resistance within this pathogen is on the rise. Therefore, there is a need for novel antimicrobial therapies. To lower the time and costs of the drug discovery process, alternative in vivo models should be considered. As such, Galleria mellonella larvae can be of great value. The larval immunity consisting of several types of haemocytes is remarkably similar to the human innate immune system. Furthermore, these larvae don’t require specific housing, are cheap and are easy to handle. In this study, the use of a G. mellonella infection model to study early pneumococcal infections and treatment is proposed. Firstly, the fitness of this model to study pneumococcal virulence factors is confirmed using streptococcal strains TIGR4, ATCC®49619, D39 and its capsule-deficient counterpart R6 at different inoculum sizes. The streptococcal polysaccharide capsule is considered the most important virulence factor without which streptococci are unable to sustain an in vivo infection. Kaplan–Meier survival curves showed indeed a higher larval survival after infection with streptococcal strain R6 compared to strain D39. Then, the infection was characterized by determining the number of haemocytes, production of oxygen free radicals and bacterial burden at several time points during the course of infection. Lastly, treatment of infected larvae with the standard antibiotics amoxicillin and moxifloxacin was evaluated. Treatment has proven to have a positive outcome on the course of infection, depending on the administered dosage. These data imply that G. mellonella larvae can be used to evaluate antimicrobial therapies against S. pneumoniae, apart from using the larval model to study streptococcal properties. The in-depth knowledge acquired regarding this model, makes it more suitable for use in future research.
Collapse
Affiliation(s)
- Freya Cools
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Eveline Torfs
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Juliana Aizawa
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Bieke Vanhoutte
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Peter Delputte
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Davie Cappoen
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Paul Cos
- Laboratory of Microbiology, Parasitology and Hygiene, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| |
Collapse
|
5
|
Cools F, Torfs E, Vanhoutte B, de Macedo MB, Bonofiglio L, Mollerach M, Maes L, Caljon G, Delputte P, Cappoen D, Cos P. Streptococcus pneumoniae galU gene mutation has a direct effect on biofilm growth, adherence and phagocytosis in vitro and pathogenicity in vivo. Pathog Dis 2018; 76:5078866. [DOI: 10.1093/femspd/fty069] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- F Cools
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - E Torfs
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - B Vanhoutte
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - M Bidart de Macedo
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - L Bonofiglio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética. Cátedra de Microbiología. Junín 956. Ciudad Autónoma de Buenos Aires, Argentina
| | - M Mollerach
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética. Cátedra de Microbiología. Junín 956. Ciudad Autónoma de Buenos Aires, Argentina
| | - L Maes
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - G Caljon
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Delputte
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - D Cappoen
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Cos
- University of Antwerp, Laboratory of Microbiology, Parasitology and Hygiene. Universiteitsplein 1, 2610 Wilrijk, Belgium
| |
Collapse
|
6
|
Rowe HM, Huntley JF. From the Outside-In: The Francisella tularensis Envelope and Virulence. Front Cell Infect Microbiol 2015; 5:94. [PMID: 26779445 PMCID: PMC4688374 DOI: 10.3389/fcimb.2015.00094] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/07/2015] [Indexed: 12/20/2022] Open
Abstract
Francisella tularensis is a highly-infectious bacterium that causes the rapid, and often lethal disease, tularemia. Many studies have been performed to identify and characterize the virulence factors that F. tularensis uses to infect a wide variety of hosts and host cell types, evade immune defenses, and induce severe disease and death. This review focuses on the virulence factors that are present in the F. tularensis envelope, including capsule, LPS, outer membrane, periplasm, inner membrane, secretion systems, and various molecules in each of aforementioned sub-compartments. Whereas, no single bacterial molecule or molecular complex single-handedly controls F. tularensis virulence, we review here how diverse bacterial systems work in conjunction to subvert the immune system, attach to and invade host cells, alter phagosome/lysosome maturation pathways, replicate in host cells without being detected, inhibit apoptosis, and induce host cell death for bacterial release and infection of adjacent cells. Given that the F. tularensis envelope is the outermost layer of the bacterium, we highlight herein how many of these molecules directly interact with the host to promote infection and disease. These and future envelope studies are important to advance our collective understanding of F. tularensis virulence mechanisms and offer targets for future vaccine development efforts.
Collapse
Affiliation(s)
- Hannah M Rowe
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences Toledo, OH, USA
| | - Jason F Huntley
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences Toledo, OH, USA
| |
Collapse
|
7
|
Walters KA, D'Agnillo F, Sheng ZM, Kindrachuk J, Schwartzman LM, Kuestner RE, Chertow DS, Golding BT, Taubenberger JK, Kash JC. 1918 pandemic influenza virus and Streptococcus pneumoniae co-infection results in activation of coagulation and widespread pulmonary thrombosis in mice and humans. J Pathol 2015; 238:85-97. [PMID: 26383585 DOI: 10.1002/path.4638] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 08/25/2015] [Accepted: 09/07/2015] [Indexed: 12/15/2022]
Abstract
To study bacterial co-infection following 1918 H1N1 influenza virus infection, mice were inoculated with the 1918 influenza virus, followed by Streptococcus pneumoniae (SP) 72 h later. Co-infected mice exhibited markedly more severe disease, shortened survival time and more severe lung pathology, including widespread thrombi. Transcriptional profiling revealed activation of coagulation only in co-infected mice, consistent with the extensive thrombogenesis observed. Immunohistochemistry showed extensive expression of tissue factor (F3) and prominent deposition of neutrophil elastase on endothelial and epithelial cells in co-infected mice. Lung sections of SP-positive 1918 autopsy cases showed extensive thrombi and prominent staining for F3 in alveolar macrophages, monocytes, neutrophils, endothelial and epithelial cells, in contrast to co-infection-positive 2009 pandemic H1N1 autopsy cases. This study reveals that a distinctive feature of 1918 influenza virus and SP co-infection in mice and humans is extensive expression of tissue factor and activation of the extrinsic coagulation pathway leading to widespread pulmonary thrombosis.
Collapse
Affiliation(s)
| | - Felice D'Agnillo
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology Research and Review, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Food and Drug Administration, Silver Spring, MD, USA
| | - Zong-Mei Sheng
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, MD, 20892, USA
| | - Jason Kindrachuk
- Critical Care Medicine Department, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Louis M Schwartzman
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, MD, 20892, USA
| | | | - Daniel S Chertow
- Critical Care Medicine Department, National Institutes of Health (NIH), Bethesda, MD, USA.,Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, MD, 20892, USA
| | - Basil T Golding
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology Research and Review, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Food and Drug Administration, Silver Spring, MD, USA
| | - Jeffery K Taubenberger
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, MD, 20892, USA
| | - John C Kash
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, MD, 20892, USA
| |
Collapse
|
8
|
Anderson R, Feldman C. Key virulence factors ofStreptococcus pneumoniaeand non-typeableHaemophilus infuenzae: roles in host defence and immunisation. ACTA ACUST UNITED AC 2015. [DOI: 10.1080/10158782.2011.11441412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- R Anderson
- Ronald Anderson, Medical Research Council Unit for Infammation and Immunity, Department of Immunology, Faculty of Health Sciences, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa
| | - C Feldman
- Division of Pulmonology, Department of Internal Medicine, Charlotte Maxeke Academic Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
9
|
Cole J, Aberdein J, Jubrail J, Dockrell DH. The role of macrophages in the innate immune response to Streptococcus pneumoniae and Staphylococcus aureus: mechanisms and contrasts. Adv Microb Physiol 2014; 65:125-202. [PMID: 25476766 DOI: 10.1016/bs.ampbs.2014.08.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Macrophages are critical mediators of innate immune responses against bacteria. The Gram-positive bacteria Streptococcus pneumoniae and Staphylococcus aureus express a range of virulence factors, which challenge macrophages' immune competence. We review how macrophages respond to this challenge. Macrophages employ a range of strategies to phagocytose and kill each pathogen. When the macrophages capacity to clear bacteria is overwhelmed macrophages play important roles in orchestrating the inflammatory response through pattern recognition receptor-mediated responses. Macrophages also ensure the inflammatory response is tightly constrained, to avoid tissue damage, and play an important role in downregulating the inflammatory response once initial bacterial replication is controlled.
Collapse
Affiliation(s)
- Joby Cole
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - Jody Aberdein
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - Jamil Jubrail
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - David H Dockrell
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, United Kingdom.
| |
Collapse
|
10
|
Dockrell DH, Whyte MKB, Mitchell TJ. Pneumococcal pneumonia: mechanisms of infection and resolution. Chest 2012; 142:482-491. [PMID: 22871758 DOI: 10.1378/chest.12-0210] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Vaccination and antimicrobial therapy remain the cornerstones of the management of pneumococcal pneumonia. Despite significant successes, the capacity of the pneumococcus to evolve in the face of the selective pressure of anticapsular immunity challenges immunization programs. Treatment focuses on antimicrobial therapy but ignores the central role of the dysregulated inflammatory response during pneumonia. Future therapeutic approaches need to build on the considerable recent advances in our understanding of the pathogenesis of pneumococcal pneumonia, including those from models of pneumonia. Enhancement of the essential components of the host response that prevents most colonized individuals from developing pneumonia and strategies to limit inappropriate inflammatory responses to lower respiratory tract infection are approaches that could be exploited to improve disease outcome. This review highlights recent discoveries relating to the microbial and host determinants of microbial clearance and regulation of the inflammatory response, which provide clues as to how this could be achieved in the future.
Collapse
Affiliation(s)
- David H Dockrell
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield.
| | - Moira K B Whyte
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield
| | - Timothy J Mitchell
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, England
| |
Collapse
|
11
|
Donkor ES, Stabler RA, Hinds J, Adegbola RA, Antonio M, Wren BW. Comparative phylogenomics of Streptococcus pneumoniae isolated from invasive disease and nasopharyngeal carriage from West Africans. BMC Genomics 2012; 13:569. [PMID: 23107513 PMCID: PMC3534514 DOI: 10.1186/1471-2164-13-569] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 10/18/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We applied comparative phylogenomics (whole genome comparisons of microbes using DNA microarrays combined with Bayesian-based phylogenies) to investigate S. pneumoniae isolates from West Africa, with the aim of providing insights into the pathogenicity and other features related to the biology of the organism. The strains investigated comprised a well defined collection of 58 invasive and carriage isolates that were sequenced typed and included eight different S. pneumoniae serotypes (1, 3, 5, 6A, 11, 14, 19 F and 23 F) of varying invasive disease potential. RESULTS The core genome of the isolates was estimated to be 38% and was mainly represented by gene functional categories associated with housekeeping functions. Comparison of the gene content of invasive and carriage isolates identified at least eleven potential genes that may be important in virulence including surface proteins, transport proteins, transcription factors and hypothetical proteins. Thirteen accessory regions (ARs) were also identified and did not show any loci association with the eleven virulence genes. Intraclonal diversity (isolates of the same serotype and MLST but expressing different patterns of ARs) was observed among some clones including ST 1233 (serotype 5), ST 3404 (serotype 5) and ST 3321 (serotype 14). A constructed phylogenetic tree of the isolates showed a high level of heterogeneity consistent with the frequent S. pneumoniae recombination. Despite this, a homogeneous clustering of all the serotype 1 strains was observed. CONCLUSIONS Comparative phylogenomics of invasive and carriage S. pneumoniae isolates identified a number of putative virulence determinants that may be important in the progression of S. pneumoniae from the carriage phase to invasive disease. Virulence determinants that contribute to S. pneumoniae pathogenicity are likely to be distributed randomly throughout its genome rather than being clustered in dedicated loci or islands. Compared to other S. pneumoniae serotypes, serotype 1 appears most genetically uniform.
Collapse
Affiliation(s)
- Eric S Donkor
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
- Department of Microbiology, University of Ghana Medical School, Accra, Ghana
| | - Richard A Stabler
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Jason Hinds
- Bacterial Microarray Group, St. George’s University of London, London, SW17 0RE, UK
| | | | - Martin Antonio
- Vaccinology Theme, Medical Research Council Unit, The Gambia
| | - Brendan W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| |
Collapse
|
12
|
Abstract
Pneumococcal meningitis continues to be associated with high rates of mortality and long-term neurological sequelae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation. During invasive disease, pneumococcal epithelial adhesion is followed by bloodstream invasion and activation of the complement and coagulation systems. The release of inflammatory mediators facilitates pneumococcal crossing of the blood-brain barrier into the brain, where the bacteria multiply freely and trigger activation of circulating antigen-presenting cells and resident microglial cells. The resulting massive inflammation leads to further neutrophil recruitment and inflammation, resulting in the well-known features of bacterial meningitis, including cerebrospinal fluid pleocytosis, cochlear damage, cerebral edema, hydrocephalus, and cerebrovascular complications. Experimental animal models continue to further our understanding of the pathophysiology of pneumococcal meningitis and provide the platform for the development of new adjuvant treatments and antimicrobial therapy. This review discusses the most recent views on the pathophysiology of pneumococcal meningitis, as well as potential targets for (adjunctive) therapy.
Collapse
|
13
|
Cockeran R, Steel HC, Theron AJ, Mitchell TJ, Feldman C, Anderson R. Characterization of the interactions of the pneumolysoid, Δ6 PLY, with human neutrophils in vitro. Vaccine 2011; 29:8780-2. [PMID: 21968446 DOI: 10.1016/j.vaccine.2011.09.080] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 09/19/2011] [Accepted: 09/20/2011] [Indexed: 10/17/2022]
Abstract
The pneumolysin toxoid, Δ6 PLY, is a prototype pneumococcal protein vaccine candidate. However, its potentially detrimental residual pro-inflammatory interactions with human neutrophils are unknown. In the current study the effects of the toxoid (8-1000 ng/ml) have been compared with those of wild-type pneumolysin (WT/PLY, 8 ng/ml) on neutrophil cytosolic Ca(2+) fluxes, generation of leukotriene B(4) (LTB(4)), and release of matrix metalloproteinase-9 (MMP-9), using spectrofluorimetric, and ELISA procedures (LTB(4) and MMP-9) respectively. Exposure of neutrophils to WT/PLY resulted in influx of Ca(2+) and significant (P<0.05) release of MMP-9 and generation of LTB(4). However, treatment of the cells with Δ6 PLY at concentrations of up to 1000 ng/ml had only trivial effects on Ca(2+) influx and no effects on either release of MMP-9 or LTB(4) production. The observed absence of pro-inflammatory interactions of Δ6 PLY with neutrophils is clearly an important property of this pneumococcal protein vaccine candidate.
Collapse
Affiliation(s)
- R Cockeran
- MRC Unit for Inflammation and Immunity, Department of Immunology, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa.
| | | | | | | | | | | |
Collapse
|
14
|
|
15
|
Bacterial tyrosine-kinases: structure-function analysis and therapeutic potential. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1804:628-34. [PMID: 19716442 DOI: 10.1016/j.bbapap.2009.08.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 08/07/2009] [Accepted: 08/17/2009] [Indexed: 11/21/2022]
Abstract
Since the characterization of genes encoding Ser/Thr-kinases and Tyr-kinases in bacteria, in 1991 and 1997, respectively, a growing body of evidence has been reported showing the important role of these enzymes in the regulation of bacterial physiology. While most Ser/Thr-kinases share structural similarity with their eukaryotic counterparts, it seems that bacteria have developed their own Tyr-kinases to catalyze protein phosphorylation on tyrosine. Different types of Tyr-kinases have been identified in bacteria and a large number of them are similar to ATP-binding proteins with Walker motifs. These enzymes have been grouped in the same family (BY-kinases) and the crystal structures of two of them have been recently characterized. Phosphoproteome analysis suggest that BY-kinases are involved in several cellular processes and to date, the best-characterized role of BY-kinases concerns the control of extracellular polysaccharide synthesis. Knowing the role of these compounds in the virulence of bacterial pathogens, BY-kinases can be considered as promising targets to combat some diseases. Here, we review the current knowledge on BY-kinases and discuss their potential for the development of new antibiotics.
Collapse
|
16
|
|
17
|
Habelt S, Schwaller A, Hollinger A, Mica L. Septic polyarthritis caused by Streptococcus pneumoniae: primary pneumococcal pneumonia as a risk factor in older patients? A case report. BMJ Case Rep 2009; 2009:bcr02.2009.1604. [PMID: 22140403 DOI: 10.1136/bcr.02.2009.1604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Septic polyarthritis associated to Streptococcus pneumoniae pneumonia is rarely seen and deserves description. In the present report, the case of a 77-year-old man with a 3-day clinical history of arthritis lacking anamnesis of trauma is discussed. Physical examination showed inflammatory signs and elevated inflammatory parameters in blood samples. The patient experienced pneumonia with blood cultures positive for S pneumoniae simultaneously. Arthrotomy revealed putride arthritis with S pneumoniae in culture. Therapy was initiated with intravenous benzylpenicillin. Surgical drainage and frequent retesting managed the local infection. Antibiotics had to be changed according to the specific sensitivity to ceftriaxone. Antimicrobial therapy was given intravenously for a total of 6 weeks.On follow-up no inflammatory signs were observed after 4 and 9 months. A bistrategical approach with surgical drainage and frequent retesting and antimicrobial chemotherapy may lead to a good result in the treatment of pneumococcal septic arthritis.
Collapse
Affiliation(s)
- Susanne Habelt
- Spital Maennedorf, Surgery, Asylstrasse 10, Maennedorf, 8708, Switzerland
| | | | | | | |
Collapse
|