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Farnesol is a sesquiterpene alcohol that modulates cell-to-cell communication in Candida albicans. In recent years, several studies have shown that this molecule presents inhibitory effects against non-albicans Candida species, Paracoccidioides brasiliensis and bacteria. The present study aimed at determining the effect of farnesol on the growth of strains of the Cryptococcus neoformans species complex, through microdilution assays. In addition, the effect of farnesol on the synthesis of phospholipase and protease - important virulence-associated enzymes - by C. neoformans and Cryptococcus gattii was also investigated. A total of 36 strains were studied, out of which 20 were from veterinary sources, 8 were from human cases and 8 were from a reference collection. The minimum inhibitory concentrations (MICs) were determined in accordance with the M27-A3 protocol as described by the CLSI and farnesol was tested at a concentration range of 0.29-150 μM. Phospholipase and protease activities were evaluated through growth on egg yolk agar and spectrophotometry, respectively, after pre-incubating the strains at different farnesol concentrations (MIC/4, MIC/2 and MIC). It was observed that farnesol presents an inhibitory activity against C. neoformans and C. gattii (MIC range: 0.29-75.0 μM). Although farnesol did not significantly alter phospholipase activity, a tendency to decrease this activity was observed. Concerning protease, no statistically significant differences were observed when comparing the production before and after pre-incubation at different farnesol concentrations. Based on these findings, it can be concluded that farnesol has in vitro inhibitory activity against C. neoformans and C. gattii, but has little impact on the production of the analyzed virulence factors., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The extraordinary ability of Cryptococcus species to cause disease has focused the attention of scientists on finding ways to improve their identification methods. In this study, PCR-REA, manual methods (morphological and biochemical characteristics), API 20C and VITEK 2 were used to test identify a total of 30 Cryptococcus spp. from human and veterinary sources. PCR-REA was performed using the capsular region as amplification target followed by restriction with the enzymes AgeI, BsmFI and HpaII. PCR-REA identified the strains as C. neoformans var. grubii (n=19) and C. gattii (n=8). There was no significant difference between the API 20C AUX and VITEK 2 when compared to manual methods for the identification of Cryptococcus spp. However, none of these non-manual methods were able to detect C. gattii samples. PCR-REA showed a greater level of concordance with the manual method, besides being faster and more sensitive than the other methods. Therefore, it is indicated for routine identification of Cryptococcus spp. strains., (Copyright © 2011 Elsevier B.V. All rights reserved.)

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., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The increasing incidence of candidiasis has drawn the attention of scientists and clinicians attempting to improve methods of studying Candida yeasts. PCR amplification followed by agarose gel electrophoresis (PCR-AGE) and the manual method (morphological characteristics, biochemical profiles and culturing on CHROMagar-Candida) and VITEK 2 automated method were used to test a total of 30 fungal strains from dog sources. The strains were obtained from cases of dermatitis, otitis externa and from the ears, oral mucosa, vaginal mucosa, prepuce and perianal region of clinically normal dogs. After identification as Candida yeasts by the manual method, the strains were analyzed using both VITEK and PCR-AGE methods. Isolates of C. parapsilosis ATCC 22019, C. krusei ATCC 6258 and C. albicans ATCC 10231 were included as controls. The universal primers ITS1, ITS3 and ITS4 were used in two independent PCR reactions. Of 30 yeast isolates, 3 isolates (Saccharomyces cerevisiae, C. rugosa and C. parapsilosis) that were incompletely identified by the manual method were identified with the PCR-AGE and VITEK methods. The results revealed a 96.7% and 86.7% concurrent identification between the PCR-AGE and VITEK methods versus the manual method, respectively. PCR-AGE showed a greater level of concordance with the manual method, besides being faster and more sensitive than the other methods examined, and is therefore indicated for routine diagnostic testing of Candida spp. strains from veterinary sources.