Di-K19Hc, an antimicrobial peptide as new ototopical agent for treatment of otitis media

Abstract

Conclusion: Di-K19Hc is a promising new ototopical antibiotic for treatment of middle ear infections associated with antibiotic-resistant bacteria. Objectives: Di-K19Hc was previously shown to exert profound antimicrobial activity against a variety of antibiotic-resistant bacteria and fungi. In this study, we evaluated the potential use of di-K19Hc as a topical agent for the treatment of otitis media (OM) caused by a variety of microbial pathogens including bacteria resistant to conventional antibiotics. Methods: Antimicrobial activity of di-K19Hc was measured by colony count assay. Hearing threshold was determined by measurement of auditory brainstem response in mice treated with di-K19Hc. Mice treated with gentamicin were used as a control. Results: Di-K19Hc showed much stronger antimicrobial activity against methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas aeruginosa associated with human OM than did ofloxacin. Also, it was shown that the peptide exhibited substantial dose-dependent antimicrobial activity against microbes from middle ear fluid of patients with OM. Topically applied di-K19Hc caused neither a decrease of hearing level nor loss of hair cells.

Keywords::

• Antibiotic-resistant bacteria
• ototoxicity
• round window membrane

Acknowledgments

This work was supported by a grant from the World-Class 2030 Project of Hoseo University and by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund) (KRF-2008-314-E00189).

Declaration of interest: The authors report no conflicts of interest.