Candida species isolated from the gastrointestinal tract of cockatiels (Nymphicus hollandicus): In vitro antifungal susceptibility profile and phospholipase activity

Over the past years, the incidence of yeast infections, especially candidiasis, has increased. It is known that birds, including cockatiels, harbor potentially pathogenic yeasts to human beings in their gastrointestinal tract. Thus, this work aims at determining the in vitro antifungal susceptibility and phospholipase activity of Candida spp. isolated from the gastrointestinal tract and stools of cockatiels. Sixty cockatiels were assessed and samples were collected from oral cavity, crop and cloaca and stools were collected from cages where birds were kept. Yeast species were identified according to morphological and biochemical characteristics. Amphotericin B, itraconazole and fluconazole were tested against 39 C. albicans; 12 C. tropicalis; 7 C. parapsilosis and 1 C. krusei, through broth microdilution test. These same isolates were also tested for phospholipase production, on egg yolk agar. For amphotericin B, itraconazole and fluconazole, MICs were 0.25–1 μg/mL, 0.03125 to ≥16 μg/mL and 0.5 to ≥64 μg/mL, respectively, and resistance to itraconazole and fluconazole was observed in 14 (35.89%) and 4 (10.26%) C. albicans isolates, respectively. All C. albicans were positive for phospholipase production, out of which 74.36% presented high enzymatic activity. Among non-albicans Candida species, 40% produced phospholipase. The results show that cockatiels might represent a hazard to human health, as sources of infections caused by resistant Candida spp., especially to immunocompromised individuals, children and elderly.