개 외이도염에서 광감각제인 5-ALA, MAL, CLC를 이용한 광역학 치료

Abstract

Canine otitis externa is common disorder in small animal practice with prevalence up to 20%. In a large percentage of cases, canine otitis externa is chronic and recurrent disease also that associated with drug-resistant bacteria is difficult to treat with traditional antibiotics. Photodynamic therapy (PDT) is a new strategy to exterminate pathogenic microorganisms such as bacteria and fungi. The objective of this study was to investigate an effect of photodynamic therapy against canine otitis externa using three photosensitizer (PS); 5-Aminolevulinic acid (5-ALA) and Methyl aminolevulinic acid (MAL) with semiconductor laser diode (SLD, 635nm of wave length), Chlorophyll-lipoid complex (CLC) with light-emitting diode(LED, 660nm of wave length). After PDT, dogs showed improved Otitis Index Score (OTIS) in swelling, exudate, odor and pain. A result of cytology test revealed decrease of bacteria and malassezia count in oil immersion field and colony forming units count. PDT was effective as a bacteriocide of multidrug-resistant Acinetobacterium (MRA) as well as methicillin-resistant Staphylococcus pseudintermedius (MRSP) and a fungicide of Malassezia pachydermatis . MAL and 5-ALA were more effective PS against canine otitis externa than CLC. These results suggest that PDT is a new strategy to exterminate pathogenic microorganisms such as bacteria and fungi. PDT can be considered new therapeutic approach for canine recurrent otitis externa and a countermeasure to drug resistance that is a drawback of traditional antibiotic and antifungal therapy.