Acute otitis media develops in the rat after intranasal challenge of Streptococcus pneumoniae

Objectives/Hypothesis: The rat is a frequently used animal model for middle ear research. To date, acute otitis media (AOM) has been evoked after instillation of bacteria directly into the middle ear cavity or after traumatizing the tympanic membrane. The purpose of the study was to examine whether, with an intact tympanic membrane and middle ear cavity, intranasally deposited bacteria cause AOM and how tympanic membrane stimulation influences this procedure. Study Design: In vivo, murine model. Methods: In a rat model, Streptococcus pneumoniae, type 3, was intranasally inoculated for 5 consecutive days. The tympanic membrane was treated with saline or with compound 48/80 or was left untreated. The development of AOM was evaluated by otomicroscopy, light microscopy, and middle ear culture. Results: Ninety percent of the ears developed AOM. However, when the tympanic membranes were treated with saline or compound 48/80, only 40% and 57%, respectively, developed AOM. In all, 23 of 40 ears developed AOM and 20 ears showed growth of bacteria. Conclusion: Repeated intranasal deposition of S pneumoniae, type 3, causes AOM in the rat. The development of AOM can be influenced by tympanic membrane stimulation.

[1]  G. Bloom,et al.  Mast cells in the pars flaccida of the tympanic membrane. A quantitative morphological and biochemical study in the rat , 1983, Experientia.

[2]  S. Hellström,et al.  Early structural changes in the rat tympanic membrane during pneumococcal otitis media , 2004, European Archives of Oto-Rhino-Laryngology.

[3]  T. Stigbrand,et al.  Sequential analysis of serum proteins in middle ear effusions , 1990, European Archives of Oto-Rhino-Laryngology.

[4]  S. Hellström,et al.  Degranulation of Mast Cells Provokes a Massive Inflammatory Reaction in the Tympanic Membrane , 2001, The Laryngoscope.

[5]  Jian Dong Li,et al.  Cell biology of tubotympanum in relation to pathogenesis of otitis media - a review. , 2000, Vaccine.

[6]  P. Roholl,et al.  A New Rat Model of Otitis Media Caused byStreptococcus pneumoniae: Conditions and Application in Immunization Protocols , 1999, Infection and Immunity.

[7]  C. Dahlgren,et al.  Neutrophils in mucosal secretion are functionally active , 1996, Clinical and experimental immunology.

[8]  S. Abraham,et al.  Mast cell modulation of neutrophil influx and bacterial clearance at sites of infection through TNF-α , 1996, Nature.

[9]  C. Bluestone,et al.  Pathogenesis of otitis media: role of eustachian tube. , 1996, The Pediatric infectious disease journal.

[10]  S. Hellström,et al.  Localization of hyaluronan in the human endolymphatic sac. A study using the affinity hyaluronan binding protein. , 1994, Acta oto-laryngologica.

[11]  S. Hellström,et al.  Experimental cholesteatoma in the rat. , 1994, Acta oto-laryngologica.

[12]  S. Hellström,et al.  Tympanic-membrane structure--new views. A comparative study. , 1991, ORL; journal for oto-rhino-laryngology and its related specialties.

[13]  S. Hellström,et al.  Bacteriological characterization of the effusion material in an animal model for serous and purulent otitis media. , 1990, Acta oto-laryngologica.

[14]  S. Hellström,et al.  Persistent structural changes in the middle ear mucosa of the rat, after an experimentally induced episode of pneumococcal otitis media. , 1990, Acta oto-laryngologica.

[15]  S. Hellström,et al.  A rat model for pneumococcal otitis media. , 1988, American journal of otolaryngology.

[16]  G. Bloom,et al.  An overlooked site of tissue mast cells--the human tympanic membrane. Implications for middle ear affections. , 1986, Acta oto-laryngologica.

[17]  N. Albiin,et al.  Middle Ear Mucosa in Rats and Humans , 1986, The Annals of otology, rhinology & laryngology. Supplement.

[18]  N. Albiin,et al.  The anatomy of the eustachian tube in the rat: A macro‐ and microscopical study , 1983, The Anatomical record.

[19]  G. Bloom,et al.  Middle ear effusion caused by mechanical stimulation of the external auditory canal. An experimental study in the rat. , 1983, Acta oto-laryngologica.

[20]  G. Bloom,et al.  The release of histamine from the pars flaccida mast cells one cause of otitis media with effusion? , 1982, Acta oto-laryngologica.

[21]  I. Berzins,et al.  Experimental otitis media after nasal inoculation of Streptococcus pneumoniae and influenza A virus in chinchillas , 1980, Infection and immunity.

[22]  S. Juhn,et al.  Experimental Otitis Media following Middle Ear Inoculation of Nonviable Streptococcus Pneumoniae , 1980, The Annals of otology, rhinology, and laryngology.

[23]  L. Enerbäck,et al.  Mast cells in rat gastrointestinal mucosa. 3. Reactivity towards compound 48/80. , 1966, Acta pathologica et microbiologica Scandinavica.