title: Pronounced metabolic changes in adaptation to biofilm growth by Streptococcus pneumoniae.
abstract: Streptococcus pneumoniae accounts for a significant global burden of morbidity and mortality and biofilm development is increasingly recognised as important for colonization and infection. Analysis of protein expression patterns during biofilm development may therefore provide valuable insights to the understanding of pneumococcal persistence strategies and to improve vaccines. iTRAQ (isobaric tagging for relative and absolute quantification), a high-throughput gel-free proteomic approach which allows high resolution quantitative comparisons of protein profiles between multiple phenotypes, was used to interrogate planktonic and biofilm growth in a clinical serotype 14 strain. Comparative analyses of protein expression between log-phase planktonic and 1-day and 7-day biofilm cultures representing nascent and late phase biofilm growth were carried out. Overall, 244 proteins were identified, of which >80% were differentially expressed during biofilm development. Quantitatively and qualitatively, metabolic regulation appeared to play a central role in the adaptation from the planktonic to biofilm phenotype. Pneumococci adapted to biofilm growth by decreasing enzymes involved in the glycolytic pathway, as well as proteins involved in translation, transcription, and virulence. In contrast, proteins with a role in pyruvate, carbohydrate, and arginine metabolism were significantly increased during biofilm development. Downregulation of glycolytic and translational proteins suggests that pneumococcus adopts a covert phenotype whilst adapting to an adherent lifestyle, while utilization of alternative metabolic pathways highlights the resourcefulness of pneumococcus to facilitate survival in diverse environmental conditions. These metabolic proteins, conserved across both the planktonic and biofilm phenotypes, may also represent target candidates for future vaccine development and treatment strategies. Data are available via ProteomeXchange with identifier PXD001182.
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Raymond N
authors.initials: RN
authors.lastname: Allan
authors.affiliation: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom; Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Skipp
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Public Health England, Southampton, United Kingdom.
authors.forename: Johanna
authors.initials: J
authors.lastname: Jefferies
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Public Health England, Southampton, United Kingdom; Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Clarke
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom; Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Saul N
authors.initials: SN
authors.lastname: Faust
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom; Microbial Infection and Immunity, Centre for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, United States of America.
authors.forename: Luanne
authors.initials: L
authors.lastname: Hall-Stoodley
authors.affiliation: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom; Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Webb
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D053858:Metabolic Networks and Pathways / Q000235:genetics; D058977:Molecular Sequence Annotation; D010641:Phenotype; D010933:Plankton / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins