Oxley K Scott, Thomas John G, Ramadan Hassan H
Department of Otolaryngology-Head and Neck Surgery, West Virginia University, Morgantown, West Virginia, USA.
Laryngoscope. 2007 Oct;117(10):1819-24. doi: 10.1097/MLG.0b013e3180d09ede.
Examine how ototopical medications affect biofilms on fluoroplastic tympanostomy tubes.
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.
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.
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.
Infectivity of the biofilm is neutralized by antibiotic ototopicals; however, the biofilm will progress despite treatment.
研究耳用局部用药如何影响氟塑料鼓膜造口管上的生物膜。
针对临床分离的铜绿假单胞菌生物膜，在鼓膜造口管上进行不同耳用局部用药的体外比较，处理时间为5天、10天、14天和21天。
在无菌条件下，将21根鼓膜造口管切成两半。通过橡胶水泥将其附着在两个卡尔加里生物膜装置的栓子上。装置1以菌落形成单位（CFU）评估微生物生长。装置2评估生物膜的存在情况。将管子准备好用于生物膜生长，进行培养，并应激72小时。之后，从每个装置中取出一根管子并强力冲洗。一根进行5分钟的超声处理，连续稀释，然后接种用于CFU计数。用福尔马林保存另一根用于通过扫描电子显微镜进行生物膜评估。接下来，将管子暴露于5滴环丙沙星、环丙沙星/地塞米松、地塞米松、氧氟沙星或生理盐水1小时。之后，去除耳用局部用药，在孔中加入无菌肉汤作为营养物。在治疗的5天、10天、14天和21天期间，每间隔12小时重复此操作。在最后一剂治疗间隔之前，进行划线平板培养以评估孔中的微生物生长。如前所述，在每个间隔对管子进行CFU和生物膜评估。
含抗生素滴剂的CFU中的微生物活性在第5天下降，并持续到第21天。尽管进行了治疗，生物膜从未被根除且继续发展。
耳用抗生素局部用药可中和生物膜的感染性；然而，尽管进行了治疗，生物膜仍会发展。
