Kluyveromyces fragilis as an opportunistic fungal pathogen in man.

An immunosuppressed cardiac transplant patient with pulmonary infection due to the yeast Kluyveromyces fragilis is described. Isolation of this fungus from human sources is rarely reported, and previous reports of human infection are unavailable in the modern literature. The organism is poorly pathogenic even in immunocompromised hosts. In vitro susceptibility studies with several strains presented here indicate inhibition by 5-fluorocytosine and miconazole, and borderline susceptibility to amphotericin B. The patient was treated with amphotericin B, and recovered without sequelae.