{"doi":"10.1128/mbio.00655-13","title":"Novel Role for the Streptococcus pneumoniae Toxin Pneumolysin in the Assembly of Biofilms","abstract":"<jats:title>ABSTRACT</jats:title>\n          <jats:p>\n            <jats:named-content content-type=\"genus-species\">Streptococcus pneumoniae</jats:named-content>\n            is an important commensal and pathogen responsible for almost a million deaths annually in children under five. The formation of biofilms by\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            is important in nasopharyngeal colonization, pneumonia, and otitis media. Pneumolysin (Ply) is a toxin that contributes significantly to the virulence of\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            and is an important candidate as a serotype-independent vaccine target. Having previously demonstrated that a\n            <jats:italic>luxS</jats:italic>\n            knockout mutant was unable to form early biofilms and expressed less\n            <jats:italic>ply</jats:italic>\n            mRNA than the wild type, we conducted a study to investigate the role of Ply in biofilm formation. We found that Ply was expressed in early phases of biofilm development and localized to cellular aggregates as early as 4 h postinoculation.\n            <jats:italic>S. pneumoniae ply</jats:italic>\n            knockout mutants in D39 and TIGR4 backgrounds produced significantly less biofilm biomass than wild-type strains at early time points, both on polystyrene and on human respiratory epithelial cells, cultured under static or continuous-flow conditions. Ply’s role in biofilm formation appears to be independent of its hemolytic activity, as\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            serotype 1 strains, which produce a nonhemolytic variant of Ply, were still able to form biofilms. Transmission electron microscopy of biofilms grown on A549 lung cells using immunogold demonstrated that Ply was located both on the surfaces of pneumococcal cells and in the extracellular biofilm matrix. Altogether, our studies demonstrate a novel role for pneumolysin in the assembly of\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            biofilms that is likely important during both carriage and disease and therefore significant for pneumolysin-targeting vaccines under development.\n          </jats:p>\n          <jats:p>\n            <jats:bold>IMPORTANCE</jats:bold>\n            The bacterium\n            <jats:named-content content-type=\"genus-species\">Streptococcus pneumoniae</jats:named-content>\n            (commonly known as the pneumococcus) is commonly carried in the human nasopharynx and can spread to other body sites to cause disease. In the nasopharynx, middle ear, and lungs, the pneumococcus forms multicellular surface-associated structures called biofilms. Pneumolysin is an important toxin produced by almost all\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            strains, extensively studied for its ability to cause damage to human tissue. In this paper, we demonstrate that pneumolysin has a previously unrecognized role in biofilm formation by showing that strains without pneumolysin are unable to form the same amount of biofilm on plastic and human cell substrates. Furthermore, we show that the role of pneumolysin in biofilm formation is separate from the hemolytic activity responsible for tissue damage during pneumococcal diseases. This novel role for pneumolysin suggests that pneumococcal vaccines directed against this protein should be investigated for their potential impact on biofilms formed during carriage and disease.\n          </jats:p>","journal":"mBio","year":2013,"id":681370,"datarank":0.6782682865573562,"base_score":4.5217885770490405,"endowment":4.5217885770490405,"self_citation_contribution":0.6782682865573562,"citation_network_contribution":0.0,"self_endowment_contribution":0.6782682865573562,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":91,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1780215,"name":"Herbert P. Ludewick","orcid":null,"position":1,"is_corresponding":false},{"id":1780216,"name":"Kristen E. Howery","orcid":null,"position":2,"is_corresponding":false},{"id":1780217,"name":"Fuminori Sakai","orcid":null,"position":3,"is_corresponding":false},{"id":1487771,"name":"Hong Yi","orcid":"0000-0002-7923-4971","position":4,"is_corresponding":false},{"id":1780218,"name":"Richard M. Harvey","orcid":null,"position":5,"is_corresponding":false},{"id":305071,"name":"James C. Paton","orcid":"0000-0001-9807-5278","position":6,"is_corresponding":false},{"id":501625,"name":"Keith P. Klugman","orcid":"0000-0001-6637-728X","position":7,"is_corresponding":false},{"id":449056,"name":"Jorge E. Vidal","orcid":"0000-0003-0573-5658","position":8,"is_corresponding":false},{"id":858330,"name":"Joshua R. Shak","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Novel Role for the Streptococcus pneumoniae Toxin Pneumolysin in the Assembly of Biofilms","abstract":"<jats:title>ABSTRACT</jats:title>\n          <jats:p>\n            <jats:named-content content-type=\"genus-species\">Streptococcus pneumoniae</jats:named-content>\n            is an important commensal and pathogen responsible for almost a million deaths annually in children under five. The formation of biofilms by\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            is important in nasopharyngeal colonization, pneumonia, and otitis media. Pneumolysin (Ply) is a toxin that contributes significantly to the virulence of\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            and is an important candidate as a serotype-independent vaccine target. Having previously demonstrated that a\n            <jats:italic>luxS</jats:italic>\n            knockout mutant was unable to form early biofilms and expressed less\n            <jats:italic>ply</jats:italic>\n            mRNA than the wild type, we conducted a study to investigate the role of Ply in biofilm formation. We found that Ply was expressed in early phases of biofilm development and localized to cellular aggregates as early as 4 h postinoculation.\n            <jats:italic>S. pneumoniae ply</jats:italic>\n            knockout mutants in D39 and TIGR4 backgrounds produced significantly less biofilm biomass than wild-type strains at early time points, both on polystyrene and on human respiratory epithelial cells, cultured under static or continuous-flow conditions. Ply’s role in biofilm formation appears to be independent of its hemolytic activity, as\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            serotype 1 strains, which produce a nonhemolytic variant of Ply, were still able to form biofilms. Transmission electron microscopy of biofilms grown on A549 lung cells using immunogold demonstrated that Ply was located both on the surfaces of pneumococcal cells and in the extracellular biofilm matrix. Altogether, our studies demonstrate a novel role for pneumolysin in the assembly of\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            biofilms that is likely important during both carriage and disease and therefore significant for pneumolysin-targeting vaccines under development.\n          </jats:p>\n          <jats:p>\n            <jats:bold>IMPORTANCE</jats:bold>\n            The bacterium\n            <jats:named-content content-type=\"genus-species\">Streptococcus pneumoniae</jats:named-content>\n            (commonly known as the pneumococcus) is commonly carried in the human nasopharynx and can spread to other body sites to cause disease. In the nasopharynx, middle ear, and lungs, the pneumococcus forms multicellular surface-associated structures called biofilms. Pneumolysin is an important toxin produced by almost all\n            <jats:named-content content-type=\"genus-species\">S. pneumoniae</jats:named-content>\n            strains, extensively studied for its ability to cause damage to human tissue. In this paper, we demonstrate that pneumolysin has a previously unrecognized role in biofilm formation by showing that strains without pneumolysin are unable to form the same amount of biofilm on plastic and human cell substrates. Furthermore, we show that the role of pneumolysin in biofilm formation is separate from the hemolytic activity responsible for tissue damage during pneumococcal diseases. This novel role for pneumolysin suggests that pneumococcal vaccines directed against this protein should be investigated for their potential impact on biofilms formed during carriage and disease.\n          </jats:p>","is_dataset_classified":null,"base_score":4.5217885770490405,"endowment":4.5217885770490405,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"24023386","pmcid":null,"openalex_id":"https://openalex.org/W2150827914","authors":[],"funders":[{"funder_name":"NIGMS NIH HHS","grant_id":"T32 GM008169","title":null},{"funder_name":"NCRR NIH HHS","grant_id":"UL1 RR025008","title":null},{"funder_name":"NCATS NIH HHS","grant_id":"UL1 TR000454","title":null}],"total_grants":3,"fwci":6.9723,"citation_percentile":0.97690689,"influential_citations":0,"citation_trend":[{"year":2013,"count":1},{"year":2014,"count":12},{"year":2015,"count":10},{"year":2016,"count":13},{"year":2017,"count":14},{"year":2018,"count":9},{"year":2019,"count":8},{"year":2020,"count":7},{"year":2021,"count":5},{"year":2022,"count":6},{"year":2023,"count":3},{"year":2024,"count":1},{"year":2025,"count":1},{"year":2026,"count":1}],"oa_status":"gold","license":"cc-by","oa_locations":[{"url":"https://doi.org/10.1128/mbio.00655-13","host_type":"journal"},{"url":"https://doi.org/10.1128/mbio.00655-13","host_type":"publisher"},{"url":"https://journals.asm.org/doi/pdf/10.1128/mBio.00655-13","host_type":"publisher"},{"url":"https://pubmed.ncbi.nlm.nih.gov/24023386","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/3774193","host_type":"repository"},{"url":"http://hdl.handle.net/2440/81718","host_type":"repository"},{"url":"https://doaj.org/article/cb7b494c6a8a40c1b8ae7c780fbb40da","host_type":"repository"}],"fields_of_study":["Pneumonia and Respiratory Infections","Bacterial Infections and Vaccines","Inhalation and Respiratory Drug Delivery","Bacterial Proteins","Biofilms","Epithelial Cells","Gene Expression Regulation, Bacterial","Hemolysin Proteins","Humans","Lung","Pneumococcal Infections","Streptococcus pneumoniae","Streptolysins"],"mesh_terms":["Bacterial Proteins","Epithelial Cells","Hemolysin Proteins","Humans","Lung","Pneumococcal Infections","Streptococcus pneumoniae","Streptolysins","Gene Expression Regulation, Bacterial","Biofilms"],"keywords":["Pneumolysin","Biofilm","Microbiology","Streptococcus pneumoniae","Virulence","Biology","Pathogen","Toxin","Bacteria","Gene","Antibiotics"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T17:38:56.835921Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}