AOS037 - Evaluation of Safety and Efficacy of Povidone-Iodine Solution as an Ototopical Treatment in a Murine Model of Chronic Suppurative Otitis Media
Saturday, April 30, 2022
10:38 AM – 10:45 AM CT
Location: Landmark A
Adam C. Kaufman, MD, PhD
Brian Bacacao, BS
Laurent Bekale, PhD
Peter L. Santa Maria, MD, PhD
Hypothesis: Povidone-Iodine solution can eliminate biofilms and persister cells rapidly in in vivo achievable concentrations without inducing ototoxicity.
Background: Chronic suppurative otitis media (CSOM) is a substantial global problem. Current treatment options often induce a temporary remission without leading to a permanent cessation of symptoms secondary to the inability treatments inability to eliminate biofilm and persister cells. Povidone-Iodine has been shown to be able to clear biofilm and planktonic cells in in vitro assays, but there are reports of ototoxic effects limiting its utility.
Methods: Bacterial and biofilm growth with quantification by spectrophotomer, murine auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE), immunohistochemistry, in vivo povidone-iodine treatment of murine CSOM, persister cell assay
Results: Commercially available 10% povidone-iodine solution is able to completely eradicate multiple clinical strains of pseudomonas aeruginosa (PA) and staphylococcus aureas (SA) is as little as 5 minutes of exposure. 1% povidoneiodine solutions are able to reduce bioburden of PA and SA to levels that are not clinically relevant (104 CFU/mL). Mice that have received a transtympanic injection of 1% povidone-iodine solution did not have significantly different ABR or DPOAE results compared to mice that received a saline injection. The DPOAE of mice that received a povidoneiodine scrub worsened by almost 30 decibels which is a significant change (p < 0.05). Immunohistochemistry was performed to confirm loss of outer hair cells. A murine model of CSOM was inoculated with PA and a persister cell assay was completed to determine clearance of infection.
Conclusions: Povidone-iodine solution is effective at eliminating biofilm and persister cells at in vivo achievable concentrations. The diluted solution does not have ototoxic potential while the scrub variant, which contains detergents, significantly worsened hearing thresholds after a single treatment.
*Define Professional Practice Gap & Educational Need: CSOM is a recalcitrant disease requiring frequent courses of ototopical treatments often eventually needing surgical intervention. There is a desperate need for more effective medical options. Povidone-iodine is often overlooked as treatment option due to prior reports of ototoxicity. Diluted solutions of povidone-iodine without detergent do not appear to raise the hearing thresholds in mice. Povidone-iodine solutions are able to clear biofilm and persister cells of PA and SA.
*Learning Objective: Povidone-iodine is able to rapidly sterilize PA and SA in all bacterial states Povidone-iodine scrub is ototoxic while the solution variant does not appear to impact ABR and DPOAE in murine models
*Desired Result: Diluted povidone-iodine solutions should be considered earlier in the treatment algorithm for CSOM.
Level of Evidence – Laboratory Science
Indicate IRB or IACUC: IACUC Protocol 33535 Stanford University