The Open Mycology Journal

2013, 7 : 7-10
Published online 2013 December 30. DOI: 10.2174/1874437020131210001
Publisher ID: TOMYCJ-7-7

Evaluation of In Vitro Synergistic Interaction of Miconazole and Polymyxin B Against Clinical Strains of Malassezia pachydermatis

Elisa Chiavassa , Andrea Peano and Mario Pasquetti
Settore di Parassitologia e Malattie Parassitarie, Dipartimento di Scienze Veterinarie, Università degli Studi di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco (Torino), Italy.

ABSTRACT

Malassezia pachydermatis is a yeast that is frequently involved as a secondary/perpetuating factor in canine otitis externa, along with numerous species of bacteria. As a result, otitis is generally treated with topical therapies using combinations of antifungal, antimicrobial and anti-inflammatory agents. The evaluation of the combined effect of drugs included in commercially available products is therefore important. In vitro synergy of polymyxin B and miconazole has been demonstrated against one strain type of M. pachydermatis. This study was aimed at investigating the in vitro interactions of these two agents against five clinical strains of this yeast. A chequerboard broth microdilution method was employed. We observed a synergistic action against all strains tested (fractional inhibitory concentration index comprised between 0.2 and 0.4). Our results indicate a strong therapeutic value for the association of these antimicrobial agents in the treatment of canine otitis externa caused by M. pachydermatis.

Keywords:

Dog, Malassezia pachydermatis, miconazole.