Evaluation of a model for studies on sequelae after acute otitis media in the Mongolian gerbil.
CONCLUSIONS
The model appears relevant for studies on sequelae after acute otitis media (AOM), and may be the seed of a new, chronic tympanic membrane perforation model in the gerbil.


OBJECTIVE
To evaluate an experimental model for abortive otitis media and to assess the structural and functional changes of the tympanic membrane in the resolving phase.


METHODS
The middle ears of 16 Mongolian gerbils were inoculated with type 6a Streptococcus pneumoniae. Half of the animals were treated with antibiotics on days 4-6, when otoscopy was performed as well. After 1, 2, 3 or 4 weeks the animals were sacrificed and their tympanic membranes were examined by otoscopy, dissection microscopy, light microscopy and moire interferometry.


RESULTS
On days 4 and 6 AOM was produced in approximately 80% of the animals and perforations prevailed in approximately 30% at the study end points. Clinical signs of AOM and oedema of the tympanic membrane had already started to reduce after 1 week, and often resolved within 2 weeks. The mechanical stiffness of the tympanic membrane remained relatively unharmed in the non-perforated ears. The antibiotic treatment seemed to reduce the duration of oedema but not the perforation rate.
Von Unge
Magnus
M
Department of Otorhinolaryngology, Karolinska University Hospital and Institute, Stockholm, Sweden. magnusvu@hotmail.com
Decraemer
Willem F
WF
Buytaert
Jan A N
JA
Dirckx
Joris J J
JJ
D000208:Acute Disease; D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004195:Disease Models, Animal; D004487:Edema / Q000188:drug therapy / Q000473:pathology; D005260:Female; D005849:Gerbillinae; D008853:Microscopy; D010033:Otitis Media / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D038781:Otoscopy; D011008:Pneumococcal Infections / Q000150:complications / Q000188:drug therapy; D013296:Streptococcus pneumoniae; D014432:Tympanic Membrane / Q000473:pathology; D018058:Tympanic Membrane Perforation / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D014945:Wound Healing / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D000667:Ampicillin