title: Infection of zebrafish embryos with live fluorescent Streptococcus pneumoniae as a real-time pneumococcal meningitis model.
abstract: Streptococcus pneumoniae is one of the most important causes of bacterial meningitis, an infection where unfavourable outcome is driven by bacterial and host-derived toxins. In this study, we developed and characterized a pneumococcal meningitis model in zebrafish embryos that allows for real-time investigation of early host-microbe interaction.
  
  
  
  Zebrafish embryos were infected in the caudal vein or hindbrain ventricle with green fluorescent wild-type S. pneumoniae D39 or a pneumolysin-deficient mutant. The kdrl:mCherry transgenic zebrafish line was used to visualize the blood vessels, whereas phagocytic cells were visualized by staining with far red anti-L-plastin or in mpx:GFP/mpeg1:mCherry zebrafish, that have green fluorescent neutrophils and red fluorescent macrophages. Imaging was performed by fluorescence confocal and time-lapse microscopy.
  
  
  
  After infection by caudal vein, we saw focal clogging of the pneumococci in the blood vessels and migration of bacteria through the blood-brain barrier into the subarachnoid space and brain tissue. Infection with pneumolysin-deficient S. pneumoniae in the hindbrain ventricle showed attenuated growth and migration through the brain as compared to the wild-type strain. Time-lapse and confocal imaging revealed that the initial innate immune response to S. pneumoniae in the subarachnoid space mainly consisted of neutrophils and that pneumolysin-mediated cytolytic activity caused a marked reduction of phagocytes.
  
  
  
  This new meningitis model permits detailed analysis and visualization of host-microbe interaction in pneumococcal meningitis in real time and is a very promising tool to further our insights in the pathogenesis of pneumococcal meningitis.
authors.affiliation: Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.|Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Kin Ki
authors.initials: KK
authors.lastname: Jim
authors.affiliation: Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: JooYeon
authors.initials: J
authors.lastname: Engelen-Lee
authors.affiliation: Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
authors.forename: Astrid M
authors.initials: AM
authors.lastname: van der Sar
authors.affiliation: Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
authors.forename: Wilbert
authors.initials: W
authors.lastname: Bitter
authors.affiliation: Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Matthijs C
authors.initials: MC
authors.lastname: Brouwer
authors.affiliation: Department of Medical Microbiology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.|The Netherlands Reference Laboratory for Bacterial Meningitis, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Arie
authors.initials: A
authors.lastname: van der Ende
authors.affiliation: Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Veening
authors.affiliation: Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Diederik
authors.initials: D
authors.lastname: van de Beek
authors.affiliation: Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands. vandenbrouckegrauls@vumc.nl.|Department of Medical Microbiology and Infection Control, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands. vandenbrouckegrauls@vumc.nl.
authors.forename: Christina M J E
authors.initials: CM
authors.lastname: Vandenbroucke-Grauls
mesh_terms: D000367:Age Factors; D000818:Animals; D030801:Animals, Genetically Modified; D001812:Blood-Brain Barrier / Q000382:microbiology / Q000473:pathology; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian / Q000382:microbiology; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007113:Immunity, Innate / Q000502:physiology*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008586:Meningitis, Pneumococcal / Q000235:genetics / Q000382:microbiology* / Q000401:mortality / Q000473:pathology*; D013296:Streptococcus pneumoniae / Q000472:pathogenicity*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism; D000097573:Red Fluorescent Protein
chemical_list: D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D029961:Zebrafish Proteins; D000097573:Red Fluorescent Protein
keywords: Host-microbe interaction; Live cell imaging; Pneumococcal meningitis; Pneumolysin; Streptococcus pneumoniae; Zebrafish