Epidemiology of Candida albicans infections and role of non-Candida-albicans yeasts
ABSTRACT Infections of the skin and the mucous membranes due to Candida species may occur either in immuncompromised or in non-immuncompromised patients. This is in contrast to systemic candidiasis (e.g. candidemia) which is only seen in severely immunocompromised patients. Bloodstream infections caused by Candida species are increasingly recognized in critical ill adult and pediatric individuals, with significant associated morbidity and mortality. Candida albicans is the single most common fungal species causing nosocomial infections. However, non-Candida albicans spp., including fluconazole-less-susceptible Candida glabrata, have become more common pathogens. In some patient populations such as hematological (neutropenic) patients Non-C. albicans species are detected much more frequently as compared to non-neutropenic patients in the intensive care. Non-C. albicans species are more likely to occur in patients, who receive or have received antifungal therapy with azoles (e.g. fluconazole). In this review the current epidemiological trends in mucosal and invasive candidiasis are discussed with regard to the role of non-Candida albicans species as the causative agent in immunocompromised patients.
- SourceAvailable from: Luiz Claudio Miletti
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- "Increasing numbers of immunocompromised individuals (in association with AIDS, treatments for cancer and immune-related diseases, organ and tissue transplantation, diabetes, premature birth or even advanced age) are at high risk for opportunistic fungal infections, in particular mucosal or systemic candidiasis. Although the majority of fungal infections in humans are caused by Candida albicans, an increasing number are being attributed to other Candida species, in particular C. glabrata (Richardson 2005; Ruhnke 2006; Pfaller et al. 2014). This opportunistic pathogen, formerly classified as Torulopsis glabrata, can be found as a commensal yeast in healthy individuals, and in the environment is found exclusively in association with mammals, which reflects the success of his commensal lifestyle. "
ABSTRACT: The emergent pathogen Candida glabrata differs from other yeasts because it assimilates only two sugars, glucose and the disaccharide trehalose. Since rapid identification tests are based on the ability of this yeast to rapidly hydrolyze trehalose, in this work a biochemical and molecular characterization of trehalose catabolism by this yeast was performed. Our results show that C. glabrata consumes and ferments tre-halose, with parameters similar to those observed during glucose fermentation. The presence of glucose in the medium during exponential growth on trehalose revealed extracellular hydrolysis of the sugar by a cell surface acid trehalase with a pH optimum of 4.4. Approximately ∼30% of the total enzymatic activity is secreted into the medium during growth on trehalose or glycerol. The secreted enzyme shows an apparent molecular mass of 275 kDa in its native form, but denaturant gel electrophoresis revealed a protein with ∼130 kDa, which due to its migration pattern and strong binding to concanavalin A, indicates that it is probably a dimeric glycoprotein. The secreted acid trehalase shows high affinity and activity for trehalose, with K m and V max values of 3.4 mM and 80 U (mg protein) −1 , respectively. Cloning of the CgATH1 gene (CAGLOK05137g) from de C. glabrata genome, a gene showing high homology to fungal acid trehalases, allowed trehalose fermentation after heterologous expression in Saccharomyces cerevisiae.Microbiological Research 10/2015; 179:12-19. DOI:10.1016/j.micres.2015.06.008 · 1.94 Impact Factor
- "Candida albicans is the predominant cause of invasive fungal infections from yeasts (Ruhnke, 2006; Horn et al., 2009). This is the species most frequently isolated from fungal infections. "
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- "The difficulties associated with the management of Candida infections have been increasing during the last decades due to their low susceptibility to the available antifungal therapies (Ruhnke, 2006; Naeini et al., 2009). Thus, in order to overcome this problem it is of major importance to identify new compounds, especially natural ones, that are active against the most broaden spectrum of Candida species. "
ABSTRACT: The life-threatening mycoses caused by opportunistic fungal pathogens (mainly species from the genus Candida) associated with nosocomial infections, are one of the major health problems in our days. Therefore, it is crucial to identify new compounds, especially natural ones, that are active against the most broaden spectrum of Candida species. Herein, a screening of the antifungal potential of a phenolic extract of Cistus ladanifer from Northeastern Portugal, against Candida species was performed. Furthermore, the extract was characterized by HPLC–DAD-ESI/MS. Phenolic acids and derivatives (3.96 mg/g extract), ellagic acid derivatives (30.34 mg/g extract), and flavonoids (4.15 mg/g extract), such as catechins, flavonols and flavones, were found in the sample. The most abundant group was ellagic acid derivatives in which punicalagin gallate, a derivative of punicalagin attached to gallic acid, was found in highest amount (15.99 ± 0.02 mg/g extract). These compounds (i.e., ellagitannins) could be related to the strong inhibition of Candida albicans, C. glabrata and C. parapsilosis growth (MIC < 0.05 mg/mL). Moreover, the best antifungal activity was against C. glabrata, where the studied extract was able to cause at least 3 log of reduction at concentrations below 0.05 mg/mL and a total growth inhibition at concentrations above 0.625 mg/mL.Industrial Crops and Products 01/2013; 41(1):41. DOI:10.1016/j.indcrop.2012.03.038 · 2.84 Impact Factor