Microbiology of acute otitis media with tympanostomy tubes.

OBJECTIVE: The objective was to determine the types of organisms which cause acute otitis media with a tympanostomy tube and to ascertain their frequency distribution. STUDY DESIGN AND SETTING: Prospective, randomized, multi-institutional clinical trials. Both private and academic sites were included. RESULTS: 1309 isolates were recovered from 956 draining ears. Streptococcus pneumonia was recovered from 17%, Staphylococcus aureus from 13%, H flu from 18% and Pseudomonas aeruginosa from 12%. Fungal organisms were recovered from 5% of total isolates and 4% from single isolates. CONCLUSIONS: AOMT is microbiologically different than AOM with an intact TM. There is no evidence that resistance develops as result of topical treatment. SIGNIFICANCE: The study demonstrates that AOMT is frequently caused by organisms not susceptible to oral antibiotics approved for children, but which are sensitive to topical ear drops.