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Effect of Ototopical Medications on Tympanostomy Tube Biofilms
Author(s) -
Oxley K Scott,
Thomas John G.,
Ramadan Hassan H.
Publication year - 2007
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/mlg.0b013e3180d09ede
Subject(s) - biofilm , tympanostomy tube , ciprofloxacin , microbiology and biotechnology , dexamethasone , pseudomonas aeruginosa , medicine , antibiotics , surgery , bacteria , biology , genetics , otitis
Objective: Examine how ototopical medications affect biofilms on fluoroplastic tympanostomy tubes. Study Design: In vitro comparison of different ototopical medications against a clinical isolate of Pseudomonas aeruginosa biofilm on tympanostomy tubes treated for 5, 10, 14, and 21 days. Methods: Under sterile conditions 21 tympanostomy tubes were cut in half. These were attached to pegs of two Calgary Biofilm Devices via rubber cement. Device 1 evaluated microbial growth as colony forming units (CFUs). Device 2 evaluated presence of biofilms. Tubes were prepped for biofilm growth, incubated, and stressed for 72 hours. Afterward, one tube per device was removed and forcefully washed. One was sonificated for 5 minutes, serially diluted, and plated for CFUs. Formalin preserved the other for biofilm evaluation by scanning electron microscopy. Next, tubes were exposed to five drops of Ciprofloxacin, Ciprofloxacin/Dexamethasone, Dexamethasone, Ofloxacin, or saline for 1 hour. Afterward, the ototopicals were removed and sterile broth was placed in the wells as a nutrient. This was repeated every 12 hours for 5, 10, 14, and 21 days of treatment. Prior to the last dose of treatment intervals, a streak plate was performed to evaluate for microbial growth in the wells. The tubes were evaluated for CFUs and biofilms at each interval as previously described. Results: Microbial activity in CFUs decreased by day 5 and continued through day 21 for the antibiotic containing drops. Despite treatment, the biofilm was never eradicated and continued to progress. Conclusions: Infectivity of the biofilm is neutralized by antibiotic ototopicals; however, the biofilm will progress despite treatment.