Cryptococcus neoformans is a basidiomycetous, the etiologic agent of cryptococcosis, yeast-like fungus which, following inhalation from an environmental source causes respiratory and neurological disease in humans and animals. Cryptococcal infections can be fatal if the host does not have adequate T-cell-dependent immune function. Most important predisposing factors for infection with C. neoformans are virus immunodeficiency infection, use of immunosuppressive drugs, organ and bone marrow transplantation, chronic leukemia, and lymphomas (Dismukes 1988, Velegraki, et al. 2001, Horta et al. 2002. Kwon-Chung et al. (1982) established two varieties that were recognized: var. neoformans and var. gattii. Currently we recognize 3 varieties: grubii -serotype A-, gattiiserotype B, C, -and neoformans -serotype D (Franzot et al. 1999). Most likely, var. gattii will be renamed as a novel species and called C. bacillisporus (Diaz et al. 2000).This fungus appears in yeast form, presenting spherical cells (5-100 µm in diameter) with single or multiple buds. The colonies are cream-colored, glossy, viscous, and moist, the amount of mucous being directly related to the size of the capsule. Among the various virulence factors, the most significant are capsular polysaccharides such as glucuronoxylan, galactoxilamanane, and mannoproteins (Kurtzman & Fell 1998, Lacaz et al. 2002, Chiapello et al. 2003, Ellerbroek et al. 2004.The samples of C. neoformans maintained in our Fungus Collection are especially useful for biotechnology projects, scientific research related to antifungal therapy, determination of molecular characteristics, production antigen, and instructional programs, as well as functional as reference cultures. Various preservation techniques are used: successive subculture on solid medium (with or without the addition of mineral oil); spore cultivation (in soil, sand, or silica gel); lyophilized; liquid nitrogen storage; and suspension in distilled water (Castellani 1963, 1967, Urdaneta et al. 1965, Bosmans 1974, Rodrigues et al. 1992, Cavalcanti & Cavalcanti 1994, Spencer & Spencer 1996.With the advent of molecular biology, various techniques have come to be used to analyze the genotype of the potential polymorphism of fungus samples. These include randomly amplified polymorphic DNA (RAPD), pulsed-field gel electrophoresis, (PFGE), restriction fragment length polymorphism (RFLP), and amplified fragment length polymorphism (AFLP). The cost of performing the RFLP, PFGE, and AFLP techniques is prohibitive. However, the RAPD method can be performed at a relatively low cost. This technique suits our needs perfectly, not only due to its cost-effectiveness but also to its reproducibility (Willians 1990).In our Fungus Collection, samples of C. neoformans have been maintained in successive subcultures since 1930. In the 1970s, some of these samples were selected to be stored using the lyophilization technique. The preservation method of choice in our laboratory is still successive subculture since it is considered a simple method...
Candida spp. are responsible for most opportunistic fungal infections. The rapid and accurate identification of this type of yeast in hospitalized patients is critical for their effective treatment and prevention of complications arising from resistant strains. Objective: Evaluate the prevalence, as well as factors that are associated with oral candidiasis in 240 patients who were admitted to the dermatology infirmary of a tertiary hospital in Sao Paulo, Brazil. Methods: It is a descriptive, observational, and cross-sectional study, in which the clinical condition of each patient was analyzed and a direct mycological examination and culture for fungi were performed. Microorganisms were identified using phenotypic methods and mass spectrometry (MALDI-TOF). Results: The prevalence of Candida spp. was 28.7%. C. albicans was the most common species (84%), followed by C. glabrata (4.34%), C. tropicalis (4.34%), C. parapsilosis (4.34%), C. krusei (1.4%), and C. dubliniensis (1.4%). As discovered by univariate and multivariate logistic regression analysis, such factors as the use of oral prosthesis and immunosuppression increased the risk of candidiasis. Conclusion: Hospitalized patients showed a significant prevalence of oral candidiasis, related to predisposing local and systemic factors, which affected their microbiota. Although C. albicans was the primary microorganism of the infection, other species were identified. Clinical relevance: The techniques that were used in this study identified the precise causative agent of the infection in a short period, allowing us to modify the therapeutic regimen so that, in turn, direct implications on the patient’s health were presented.
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