The incidence/significance of fungal infections in marine animals has not been extensively investigated. Likewise, the laboratory evaluation of antifungal agents against fungi isolated from such animals has been sparse as well as information regarding antifungal therapy. We had the opportunity to evaluate 66 fungal isolates recovered from various marine animals over a period of one year and four months. Specimens were obtained from Sea World, Inc., locations in Florida (28), California (6), Ohio (1), and Texas (31). Fungi were recovered from (in decreasing order of incidence) dolphins, whales, penguins, sharks, otter, and walrus. Fungal isolates were both yeasts and moulds with the former predominating. The major species isolated, by far, was the yeast Candida albicans. The spectrum of fungi isolated were classified in the genera Candida, Torulopsis Rhodotorula, unclassified yeasts, Aspergillus, Mucor, Fusarium, Scopulariopsis, Scopulariopsis, Scopulariopsis, Scopulariopsis, Penicillium, Paecilomyces, Epicoccum, and Cladosporium. Striking associations included: aspergilli with marine birds (as with other avian species), Fusarium with Bonnet Head sharks, and Candida spp. with marine mammals - dolphins, whales, and walrus. While not all organisms isolated were etiologic agents of disease, animal health care professionals at all locations felt many animals were experiencing mycotic infections. It is of interest that many of the causative fungi represent the same species which cause disease in humans; particularly in immunosuppressed hosts.

Because polyene antifungal agents, e.g., amphotericin B, engender considerable toxicity and are difficult to administer to this animal population, therapy was undertaken with the azole group of antimycotics - ketoconazole (KETO) and itraconazole (ITRA). In vitro susceptibility testing via a macro-broth dilution method demonstrated that KETO and ITRA were very active against the majority of isolates. Therapeutic response following treatment correlated well with in vitro findings. Minimum inhibitory concentrations (MICs) for selected fungi were:

Arithmetic Mean MIC [Geometric Mean MIC] - both in μg/ml

In general, mould-fungi were more resistant than yeast-fungi to azole antifungals. Laboratory testing of these antifungals may offer animal care providers clinically relevant information regarding therapeutic options. This limited experience suggests that azole antimycotics merit further evaluation as potentially efficacious, non-toxic, and practical agents for the treatment of fungal infections in this distinctive animal population.