Browsing by Author "Thompson, Claudette"
Now showing items 1-20 of 22
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Age-Specific Immunoglobulin G (IgG) and IgA to Pneumococcal Protein Antigens in a Population in Coastal Kenya
Laine, C.; Mwangi, T.; Thompson, Claudette M.; Obiero, J.; Lipsitch, Marc; Scott, J. A. G. (American Society for Microbiology, 2004)Streptococcus pneumoniae is the primary etiological agent of community-acquired pneumonia and a major cause of meningitis and bacteremia. Three conserved pneumococcal proteins-pneumolysin, pneumococcal surface adhesin A ... -
Antibodies to Conserved Pneumococcal Antigens Correlate with, but Are Not Required for, Protection against Pneumococcal Colonization Induced by Prior Exposure in a Mouse Model
Trzcinski, K.; Thompson, Claudette M.; Malley, Richard; Lipsitch, Marc (American Society for Microbiology, 2005)In mice following intranasal exposure to Streptococcus pneumoniae, protection against pneumococcal colonization was independent of antibody but dependent on CD4+ T cells. Nonetheless, concentrations of antibodies to three ... -
Antibody-Independent, Interleukin-17A-Mediated, Cross-Serotype Immunity to Pneumococci in Mice Immunized Intranasally with the Cell Wall Polysaccharide
Malley, Richard; Srivastava, Amit; Lipsitch, Marc; Thompson, Claudette M.; Watkins, C.; Tzianabos, A.; Anderson, Porter (American Society for Microbiology, 2006)Serotype-specific immunity to Streptococcus pneumoniae is conferred by antibodies to the capsular polysaccharides, which define the 90 known serotypes. Whether antibody to the species-common cell wall polysaccharide (C-Ps) ... -
Antigenic Variation in Streptococcus pneumoniae PspC Promotes Immune Escape in the Presence of Variant-Specific Immunity
Georgieva, Maria; Kagedan, L.; Lu, Ying-Jie; Thompson, Claudette M.; Lipsitch, Marc (American Society for Microbiology, 2018) -
CD4+ T cells mediate antibody-independent acquired immunity to pneumococcal colonization
Malley, Richard; Trzcinski, K.; Srivastava, Amit; Thompson, Claudette M.; Anderson, Porter; Lipsitch, Marc (Proceedings of the National Academy of Sciences, 2005)Acquired immunity to Streptococcus pneumoniae (pneumococcus) has long been assumed to depend on the presence of anticapsular antibodies. We found, however, that colonization with live pneumococci of serotypes 6B, 7F, or ... -
Construction of Otherwise Isogenic Serotype 6B, 7F, 14, and 19F Capsular Variants of Streptococcus pneumoniae Strain TIGR4
Trzcinski, K.; Thompson, Claudette M.; Lipsitch, Marc (American Society for Microbiology, 2003)The polysaccharide capsule is the primary virulence factor in Streptococcus pneumoniae. There are at least 90 serotypes of S. pneumoniae, identified based on the immunogenicity of different capsular sugars. The aim of this ... -
Development of a model of focal pneumococcal pneumonia in young rats
Malley, Richard; Stack, Anne Marie; Husson, Robert Neil; Thompson, Claudette M.; Fleisher, Gary Robert; Saladino, Richard A (BioMed Central, 2004)Background: A recently licensed pneumococcal conjugate vaccine has been shown to be highly effective in the prevention of bacteremia in immunized children but the degree of protection against pneumonia has been difficult ... -
Distinct Effects on Diversifying Selection by Two Mechanisms of Immunity Against Streptococcus pneumoniae
Li, Yuan; Gierahn, Todd; Thompson, Claudette M.; Trzciński, Krzysztof; Ford, Christopher Burton; Croucher, Nicholas Jason; Gouveia, Paulo; Flechtner, Jessica B.; Malley, Richard; Lipsitch, Marc (Public Library of Science, 2012)Antigenic variation to evade host immunity has long been assumed to be a driving force of diversifying selection in pathogens. Colonization by Streptococcus pneumoniae, which is central to the organism's transmission and ... -
Effect of Serotype on Pneumococcal Competition in a Mouse Colonization Model
Trzciński, Krzysztof; Li, Yuan; Weinberger, Daniel M.; Thompson, Claudette M.; Cordy, Derrick; Bessolo, Andrew; Malley, Richard; Lipsitch, Marc (American Society of Microbiology, 2015)ABSTRACT Competitive interactions between Streptococcus pneumoniae strains during host colonization could influence the serotype distribution in nasopharyngeal carriage and pneumococcal disease. We evaluated the competitive ... -
Identification of pneumococcal colonization determinants in the stringent response pathway facilitated by genomic diversity
Li, Yuan; Croucher, Nicholas J; Thompson, Claudette M; Trzciński, Krzysztof; Hanage, William P; Lipsitch, Marc (BioMed Central, 2015)Background: Understanding genetic determinants of a microbial phenotype generally involves creating and comparing isogenic strains differing at the locus of interest, but the naturally existing genomic and phenotypic ... -
The impact of serotype-specific vaccination on phylodynamic parameters of Streptococcus pneumoniae and the pneumococcal pan-genome
Azarian, Taj; Grant, Lindsay R.; Arnold, Brian John; Hammitt, Laura L.; Reid, Raymond; Santosham, Mathuram; Weatherholtz, Robert; Goklish, Novalene; Thompson, Claudette M.; Bentley, Stephen D.; O’Brien, Katherine L.; Hanage, William P.; Lipsitch, Marc (Public Library of Science (PLoS), 2018)In the United States, the introduction of the heptavalent pneumococcal conjugate vaccine (PCV) largely eliminated vaccine serotypes (VT); non-vaccine serotypes (NVT) subsequently increased in carriage and disease. Vaccination ... -
Interference between Streptococcus pneumoniae and Staphylococcus aureus: In Vitro Hydrogen Peroxide-Mediated Killing by Streptococcus pneumoniae
Regev-Yochay, Gili; Trzcinski, K.; Thompson, Claudette M.; Malley, Richard; Lipsitch, Marc (American Society for Microbiology, 2006)The bactericidal activity of Streptococcus pneumoniae toward Staphylococcus aureus is mediated by hydrogen peroxide. Catalase eliminated this activity. Pneumococci grown anaerobically or genetically lacking pyruvate oxidase ... -
Interleukin-17A Mediates Acquired Immunity to Pneumococcal Colonization
Gross, Jane; Bogaert, Debby; Finn, Adam; Bagrade, Linda; Zhang, Qibo; Kolls, Jay K.; Lundgren, Anna; Forte, Sophie; Lu, Ying-Jie; Srivastava, Amit Kumar; Thompson, Claudette M.; Harney, Kathleen; Anderson, Porter; Lipsitch, Marc; Malley, Richard (Public Library of Science, 2008)Although anticapsular antibodies confer serotype-specific immunity to pneumococci, children increase their ability to clear colonization before these antibodies appear, suggesting involvement of other mechanisms. We ... -
Intranasal Immunization with Killed Unencapsulated Whole Cells Prevents Colonization and Invasive Disease by Capsulated Pneumococci
Malley, Richard; Lipsitch, Marc; Stack, Anne Marie; Saladino, R.; Fleisher, Gary Robert; Pelton, S.; Thompson, Claudette M.; Briles, D.; Anderson, Porter (American Society for Microbiology, 2001)A whole-cell killed unencapsulated pneumococcal vaccine given by the intranasal route with cholera toxin as an adjuvant was tested in two animal models. This vaccination was highly effective in preventing nasopharyngeal ... -
A Modified Janus Cassette (Sweet Janus) to Improve Allelic Replacement Efficiency by High-Stringency Negative Selection in Streptococcus pneumoniae
Li, Yuan; Thompson, Claudette M.; Lipsitch, Marc (Public Library of Science, 2014)The Janus cassette permits marker-free allelic replacement or knockout in streptomycin-resistant Streptococcus pneumoniae (pneumococcus) through sequential positive and negative selection. Spontaneous revertants of Janus ... -
Protection against Nasopharyngeal Colonization by Streptococcus pneumoniae Is Mediated by Antigen-Specific CD4+ T Cells
Trzciński, Krzysztof; Thompson, Claudette M.; Srivastava, Amit; Basset, Alan Emmanuel; Malley, Richard; Lipsitch, Marc (American Society for Microbiology, 2008)CD4(+) T-cell-dependent acquired immunity confers antibody-independent protection against pneumococcal colonization. Since this mechanism is poorly understood for extracellular bacteria, we assessed the antigen specificity ... -
Recognition of pneumolysin by Toll-like receptor 4 confers resistance to pneumococcal infection
Malley, Richard; Henneke, P.; Morse, S. C.; Cieslewicz, M. J.; Lipsitch, Marc; Thompson, Claudette M.; Kurt-Jones, E.; Paton, J. C.; Wessels, Michael Robert; Golenbock, D. T. (Proceedings of the National Academy of Sciences, 2003)Streptococcus pneumoniae is one of the leading causes of invasive bacterial disease worldwide. Fragments of the cell wall and the cytolytic toxin pneumolysin have been shown to contribute substantially to inflammatory ... -
Selective and Genetic Constraints on Pneumococcal Serotype Switching
Croucher, Nicholas J.; Kagedan, Lisa; Thompson, Claudette M.; Parkhill, Julian; Bentley, Stephen D.; Finkelstein, Jonathan A.; Lipsitch, Marc; Hanage, William P. (Public Library of Science, 2015)Streptococcus pneumoniae isolates typically express one of over 90 immunologically distinguishable polysaccharide capsules (serotypes), which can be classified into “serogroups” based on cross-reactivity with certain ... -
Single-Step Capsular Transformation and Acquisition of Penicillin Resistance in Streptococcus pneumoniae
Trzcinski, K.; Thompson, Claudette M.; Lipsitch, Marc (American Society for Microbiology, 2004)The capsule (cps) locus of Streptococcus pneumoniae is flanked by the pbp2x and pbp1a genes, coding for penicillin-binding proteins, enzymes involved in cell wall synthesis that are targets for beta-lactams. This linkage ... -
SpxB Is a Suicide Gene of Streptococcus pneumoniae and Confers a Selective Advantage in an In Vivo Competitive Colonization Model
Regev-Yochay, Gili; Trzcinski, K.; Thompson, Claudette M.; Lipsitch, Marc; Malley, Richard (American Society for Microbiology, 2007)The human bacterial pathogen Streptococcus pneumoniae dies spontaneously upon reaching stationary phase. The extent of S. pneumoniae death at stationary phase is unusual in bacteria and has been conventionally attributed ...