caa a22 4500 606185917 CHVBK 20210128100833.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00405-014-2884-y doi (NATIONALLICENCE)springer-10.1007/s00405-014-2884-y Endolymphatic sac involvement in bacterial meningitis [Elektronische Daten] [Martin Møller, Christian Brandt, Christian Østergaard, Per Caye-Thomasen] The commonest sequelae of bacterial meningitis are related to the inner ear. Little is known about the inner ear immune defense. Evidence suggests that the endolymphatic sac provides some protection against infection. A potential involvement of the endolymphatic sac in bacterial meningitis is largely unaccounted for, and thus the object of the present study. A well-established adult rat model of Streptococcus pneumoniae meningitis was employed. Thirty adult rats were inoculated intrathecally with Streptococcus pneumoniae and received no additional treatment. Six rats were sham-inoculated. The rats were killed when reaching terminal illness or on day 7, followed by light microscopy preparation and PAS-Alcian blue staining. The endolymphatic sac was examined for bacterial invasion and leukocyte infiltration. Neither bacteria nor leukocytes infiltrated the endolymphatic sac during the first days. Bacteria invaded the inner ear through the cochlear aquaduct. On days 5-6, the bacteria invaded the endolymphatic sac through the endolymphatic duct subsequent to invasion of the vestibular endolymphatic compartment. No evidence of direct bacterial invasion of the sac through the meninges was found. Leukocyte infiltration of the sac occurred prior to bacterial invasion. During meningitis, bacteria do not invade the endolymphatic sac through the dura, but solely through the endolymphatic duct, following the invasion of the vestibular system. Leukocyte infiltration of the sac occurs prior to, as well as concurrent with bacterial invasion. The findings support the endolymphatic sac as part of an innate immune defense system protecting the inner ear from infection. Springer-Verlag Berlin Heidelberg, 2014 Bacterial meningitis nationallicence Inner ear nationallicence Mb Ménière nationallicence Innate immunity nationallicence Møller Martin Department of Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Rigshospitalet/Gentofte, 2100, Copenhagen, Denmark aut Brandt Christian Department of Infectious Diseases, Copenhagen University Hospital Hvidovre, Kettegård Alle 30, 2650, Hvidovre, Denmark aut Østergaard Christian Department of Clinical Microbiology, Copenhagen University Hospital Hvidovre, Kettegård Alle 30, 2650, Hvidovre, Denmark aut Caye-Thomasen Per Department of Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Rigshospitalet/Gentofte, 2100, Copenhagen, Denmark aut European Archives of Oto-Rhino-Laryngology Springer Berlin Heidelberg 272/4(2015-04-01), 843-851 0937-4477 272:4<843 2015 272 405 https://doi.org/10.1007/s00405-014-2884-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00405-014-2884-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Møller Martin Department of Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Rigshospitalet/Gentofte, 2100, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Brandt Christian Department of Infectious Diseases, Copenhagen University Hospital Hvidovre, Kettegård Alle 30, 2650, Hvidovre, Denmark aut NATIONALLICENCE 700 1- Østergaard Christian Department of Clinical Microbiology, Copenhagen University Hospital Hvidovre, Kettegård Alle 30, 2650, Hvidovre, Denmark aut NATIONALLICENCE 700 1- Caye-Thomasen Per Department of Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Rigshospitalet/Gentofte, 2100, Copenhagen, Denmark aut NATIONALLICENCE 773 0- European Archives of Oto-Rhino-Laryngology Springer Berlin Heidelberg 272/4(2015-04-01), 843-851 0937-4477 272:4<843 2015 272 405