The Effects of Antibiotics and Steroid on the Middle Ear Mucosa in the Rats with Experimental Acute Otitis Media

Park, Shi Nae; Yeo, Sang Won

Abstract

BACKGROUND AND OBJECTIVES:Prevention of mucosal changes induced by experimental pneumococcal otitis media with antibiotics was reported in the previous studies. But the effects of combined therapy with antibiotics and steroid on middle ear mucosa in acute otitis media is not determined yet. The purpose of this study was to investigate the treatment effects of antibiotics and steroid on the middle ear mucosa of experimental acute otitis media. MATERIALS AND METHOD: The right middle ear of 27 rats was inoculated with log phase type 3 streptococcus pneumoniae, and the left ear served as control. Penicillin G was administered to 9 rats, penicillin G and dexamethasone were administered to 9 rats after bacterial challenge. The animals were killed at day 4, 7 or 14 after challenge. Tympanic membrane and middle ear mucosa were examined under the surgical microscope and light microscope.
RESULTS
Untreated pneumococcal AOM has been shown to cause persistent structural changes of the middle ear mucosa. Both in antibiotics-treated group and in antibiotics and steroid-treated group, the structural changes were diminished, as compared with those of untreated infected controls. The antibiotics and steroid-treated group showed marked decrease of structural changes, especially in mucosal metaplasia to secretory epithelium. CONCLUSION: The results suggest that the combination treatment of antibiotics and steroid in acute otitis media would seem to be almost as effective in reducing treatment period and preventing the persistence of mucosal changes, which may decrease development of serous otitis media as a sequale of acute otitis media.