Isolation of antifungal-resistant Candida from the blowholes of captive dolphins

Abstract

In this study, we isolated eight strains of Candida albicans from the blowhole air cultures of eight dolphins (one Pacific white-sided dolphin and seven bottlenose dolphins) housed at the Enoshima Aquarium. The minimum inhibitory concentrations of antifungals for these isolates were determined by conducting E-test and broth microdilution assays using the CLSI M27-A3 protocol antifungal susceptibility testing method. Only one of the eight dolphins from which Candida had been isolated had been treated with amphotericin B (AMB), and four had been treated with itraconazole (ITZ). All isolates were identified as Candida albicans, and all were resistant to both ITZ and voriconazole, though the isolates exhibited susceptibility to AMB and micafungin. Based on our findings, we suspect that the frequency of occurrence of azole-resistant Candida species is increasing in captive dolphins as well as in their aquarium environments.