Gram-negative pathogen Klebsiella oxytoca is associated with spontaneous chronic otitis media in Toll-like receptor 4-deficient C3H/HeJ mice

Carol J. MacArthur, De Ann M. Pillers, Jiaqing Pang, Jacqueline M. Degagne, J. Beth Kempton, Dennis R. Trune

Research output: Contribution to journalArticle

14 Scopus citations


Conclusion. This report confirms the presence of This report confirms the presence of ggram-negative Klebsiella bacteria in the middle ear of the C3H/HeJ mouse by culture, polymerase chain reaction (PCR), and electron microscopy. Identification of the bacterial pathogen supportsconfirms that the C3H/HeJ mouse ais an excellent model for spontaneous chronic otitis media and its effects on the middle and inner ear. Objectives. The C3H/HeJ mouse has a single amino acid substitution in its Toll-like receptor 4, making it insensitive to endotoxin and suppressing initiation of the innate immune system. This study explored the bacteriology of the resultant middle ear infection by culture, PCR, histology, and electron microscopy. Materials and methods. Twelve-month-old C3H/HeJ mice were screened positive for spontaneous otitis media. Tympanocentesis and blood cultures of mice were carried out under sedation. Middle ear aspirate material and blood samples were then sent for culture and PCR. Mice were then sacrificed for bright-field and electron microscopy analysis. Results. All tympanocentesis and blood specimens grew gram-negative Klebsiella oxytoca, which was confirmed by PCR. Histopathology confirmed an intense inflammatory reaction and gram-negative bacteria in the middle and inner ears. Electron microscopy of the middle ears revealed abundant rod-shaped Klebsiella bacteria, both free and being engulfed by neutrophils.

Original languageEnglish (US)
Pages (from-to)132-138
Number of pages7
JournalActa Oto-Laryngologica
Issue number2
StatePublished - Jan 24 2008



  • Genetic animal models
  • Gram-negative infections
  • Inflammation
  • Inner ear
  • Otitis media

ASJC Scopus subject areas

  • Otorhinolaryngology

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