Open AccessMiddle Ear Irrigations Decrease the Density of Mucosal Biofilms in an Animal Model of Acute Otitis Media
Author(s) -
Walker Thomas J.,
Abi Hachem Ralph,
Angeli Simon I.,
Liu ZueZhong
Publication year - 2011
Publication title -
otolaryngology–head and neck surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.232
H-Index - 121
eISSN - 1097-6817
pISSN - 0194-5998
DOI - 10.1177/0194599811415823a283
Subject(s) - saline , shampoo , middle ear , otitis , medicine , biofilm , surgery , anesthesia , biology , pathology , bacteria , genetics
Objective Bacteria in biofilms are extremely resistant to antibiotics. Recurrent acute otitis media appears to be a disease related to biofilm formation. The goal of this study is to determine if middle ear irrigations with saline or baby shampoo could eradicate mucosal biofilms in a chinchilla model of acute otitis media. Method After a baseline ABR, middle ears of 10 chinchillas were inoculated with Haemophilus influenzae . On day 5, the ears were irrigated with saline or 1% baby shampoo using a syringe or hydrodebrider. A final ABR was obtained before the animals were euthanized and middle ear mucosa were harvested for SEM analysis. Results Biofilm formation on middle ear mucosa in chinchillas was in nonuniform distribution. SEM analysis by a blinded microscopist showed a statistically significant decrease in biofilm densities of middle ear mucosa after normal saline or 1% baby shampoo irrigations when compared with nonirrigated ears using Wilcoxon/Kruskal‐Wallis Tests ( P <. 01). No statistically significant difference in biofilm densities between normal saline and 1% baby shampoo irrigations was seen. The hearing thresholds on auditory brainstem responses (ABR) at frequencies 16 kHz, 4 kHz, 1 kHz, and 500 Hz were unchanged two days after normal saline or 1% baby shampoo irrigations. Conclusion Middle ear irrigations with 1% baby shampoo or normal saline lead to a statistically significant decrease in biofilm densities. One percent baby shampoo or normal saline are non‐ototoxic and can be safely used for middle ear irrigations. Future work in our laboratory will study the effect of a hydrodebrider prototype.