Objective: As isolates of Cryptococcus are frequently kept collection stocks in institutions, sometimes without proper characterization, we sought to determine the genotype profiles, protease and phospholipase activit...Objective: As isolates of Cryptococcus are frequently kept collection stocks in institutions, sometimes without proper characterization, we sought to determine the genotype profiles, protease and phospholipase activities “in vitro” and the susceptibility testing for azoles and amphotericin B. Methodology: 84 isolates from several regions of Brazil (40 samples from clinical origin and 44 isolates from environmental origin) were maintained at the microorganism’s bank of the Biomedical Science Institute (ICB-USP) of the São Paulo University, in São Paulo, Brazil. This isolates was submitted fungal strains determination, DNA extraction and purification, determination of genotype by URA5 gene RFLP of CGB-positive isolates, protease and phospholipase activity and susceptibility to antifungals. Results: Of six CGB positive isolates tested by RFLP-PCR, only four presented a genomic profile consistent C. gattii species (VGII), while two other were C. neoformans (VNI and VNIII), indicating the existence of canavanine-resistante C. neoformans isolates in the culture collections. The clinical isolates secreted higher levels of phospholipase and environmental isolates but no differences were observed for the protease levels. Almost all isolates were sensible to azoles and amphotericin B. Conclusion: We point out in this research the existence of C. neoformans strains resistant to canavanine and intrinsic characteristic of C. gatti. These results demonstrate the importance to perform a detailed characterization of isolates kept in culture collections.展开更多
Background: Yeasts from the genus Cryptococcus (species C. neoformans and C. gattii) are opportunistic pathogens that afflict humans with low immunity caused by diseases such as AIDS or by the usage of immunosuppressi...Background: Yeasts from the genus Cryptococcus (species C. neoformans and C. gattii) are opportunistic pathogens that afflict humans with low immunity caused by diseases such as AIDS or by the usage of immunosuppressive drugs. It is a fatal disease that has been studied around the whole world and its most fatal form is the brain cryptococcosis. Purpose: The present review describes the disease from pathogen isolation, the various clinical presentations of the disease, the most important virulence factors of yeast in human and animal model and their clinical issues. Methods: On this review, several published studies about the disease are presented. Results: Numerous researches have been done worldwide in order to find a kind of therapy that is more effective against the disease. Amphotericin B, in all forms is still the drug of choice in the treatment of the cryptococcosis. Fluconazole, as well as voriconazole in combination with amphotericin B, is recommended in the cases of treatment failure. Conclusion: This study presented has elucidated a little more about the disease. Further studies should be conducted to find more diagnoses that are accurate as well as more effective treatments for eradicating the disease. In this study, the bibliographic survey makes reference to the world literature;with regard to ecology, taxonomy, mains factors related to virulence, the clinical manifestations, the action of antifungal drugs and histopathological analysis used in an animal model, were the objectives deleterious aspects of this study, thus informing, in a simple way, the importance of this microorganism for research and researchers working with this global disease, called Cryptococcosis.展开更多
文摘Objective: As isolates of Cryptococcus are frequently kept collection stocks in institutions, sometimes without proper characterization, we sought to determine the genotype profiles, protease and phospholipase activities “in vitro” and the susceptibility testing for azoles and amphotericin B. Methodology: 84 isolates from several regions of Brazil (40 samples from clinical origin and 44 isolates from environmental origin) were maintained at the microorganism’s bank of the Biomedical Science Institute (ICB-USP) of the São Paulo University, in São Paulo, Brazil. This isolates was submitted fungal strains determination, DNA extraction and purification, determination of genotype by URA5 gene RFLP of CGB-positive isolates, protease and phospholipase activity and susceptibility to antifungals. Results: Of six CGB positive isolates tested by RFLP-PCR, only four presented a genomic profile consistent C. gattii species (VGII), while two other were C. neoformans (VNI and VNIII), indicating the existence of canavanine-resistante C. neoformans isolates in the culture collections. The clinical isolates secreted higher levels of phospholipase and environmental isolates but no differences were observed for the protease levels. Almost all isolates were sensible to azoles and amphotericin B. Conclusion: We point out in this research the existence of C. neoformans strains resistant to canavanine and intrinsic characteristic of C. gatti. These results demonstrate the importance to perform a detailed characterization of isolates kept in culture collections.
文摘Background: Yeasts from the genus Cryptococcus (species C. neoformans and C. gattii) are opportunistic pathogens that afflict humans with low immunity caused by diseases such as AIDS or by the usage of immunosuppressive drugs. It is a fatal disease that has been studied around the whole world and its most fatal form is the brain cryptococcosis. Purpose: The present review describes the disease from pathogen isolation, the various clinical presentations of the disease, the most important virulence factors of yeast in human and animal model and their clinical issues. Methods: On this review, several published studies about the disease are presented. Results: Numerous researches have been done worldwide in order to find a kind of therapy that is more effective against the disease. Amphotericin B, in all forms is still the drug of choice in the treatment of the cryptococcosis. Fluconazole, as well as voriconazole in combination with amphotericin B, is recommended in the cases of treatment failure. Conclusion: This study presented has elucidated a little more about the disease. Further studies should be conducted to find more diagnoses that are accurate as well as more effective treatments for eradicating the disease. In this study, the bibliographic survey makes reference to the world literature;with regard to ecology, taxonomy, mains factors related to virulence, the clinical manifestations, the action of antifungal drugs and histopathological analysis used in an animal model, were the objectives deleterious aspects of this study, thus informing, in a simple way, the importance of this microorganism for research and researchers working with this global disease, called Cryptococcosis.
