evaluation of the antimicrobial activity of chlorhexidine alone or in combination with ketoconazole or miconazole against clinical isolates ofand multidrug-resistant.

Abstract

() and() are common causes of canine skin infections associated with increasing antimicrobial resistance. Topical products containing chlorhexidine and azoles have been utilized to treat these infections. However, a limited number of studies have assessed the interactions between chlorhexidine and azoles againstand.To assess efficacy and potential additivity/synergy between chlorhexidine and azoles against clinical isolates ofand multidrug-resistant().A total of 30and 30isolates were tested using a modified broth microdilution method. Six twofold dilutions of 2% chlorhexidine gluconate, 1% miconazole nitrate and 0.15% ketoconazole were tested alone and in combination. Minimum inhibitory (MIC) and bactericidal/fungicidal (MBC/MFC) concentrations were recorded, and synergy, additivity or antagonism was calculated.For, the combinations of chlorhexidine/miconazole (=0.003) and chlorhexidine/ketoconazole (<0.0001) resulted in lower MICs than chlorhexidine alone. Only the chlorhexidine/ketoconazole combination had lower MBCs (=0.0071) than chlorhexidine alone. For, only the chlorhexidine/ketoconazole combination had lower MICs (<0.0001) than chlorhexidine alone. Both combinations of chlorhexidine/miconazole (=0.0028) and chlorhexidine/ketoconazole (<0.0001) resulted in lower MFCs than chlorhexidine alone. Chlorhexidine/miconazole combination showed synergy in threeisolates, but in none of theisolates. Chlorhexidine/ketoconazole showed synergy for 1 out of 30and 19 out of 30isolates.These results suggest that chlorhexidine/azole combinations are an effective topical treatment forand MP infections. Further studies should assess the efficacy of commercial products containing these compounds and their efficacy.