diversity of Glycosphingolipid Expression in Candida spp
Tagliari L; Straus AH; *Colombo A; Suzuki E; Takahashi HK. and Toledo MS.
Universidade Federal de São Paulo, Dept. of Biochemistry and *Dept. of Medicine, R. Botucatu 862, Ed. JL Prado, São Paulo, SP, Brazil
The striking increase on morbidity and mortality associated with invasive mycosis caused by Candida spp., particularly in immunocompromised patients from organ transplants, HIV infections, and cancer has raised the interest in analyzing new molecules which could help in diagnosis and therapy of this mycosis. More than 17 species of Candida have been identified as etiologic agents of bloodstream infections, such as: C. albicans, C. glabrata, C. krusei, and C. dubliniensis. C. dubliniensis was identified as a new Candida specie with morphological and biochemical characteristics analogous to C. albicans, being necessary a DNA-based methodology to distinguish these species of fungi. In this study, a new approach based on their glycosphingolipid (GSLs) profiles was used to better characterize the different species of Candida spp.
GSLs isolated from eight different species of Candida (two strains resistant to azoles) were separated in neutral (glucosylceramide, GlcCer) and acidic (mannose-inositol phosphoceramide, MIPC) fractions by DEAE-Sephadex chromatography. It was observed that the amount of GlcCer varied among the different Candida species analysed in the following decreasing order: C. dubliniensis > C. albicans 5997 > C. tropicalis > C. krusei > C. parapsilosis > C. albicans 15R. On the other hand, it was not detected the presence of GlcCer in C. glabrata, strains 8235 and 50R (sensitive and resistant to azoles, respectively). It is noteworthy that analysis using high performance thin layer chromatography (HPTLC), showed that C. dubliniensis besides GlcCer also express a compound migrating as steryl-glucoside.
Comparing all species of Candida analyzed, it was also observed a variation in MIPC amount in the following decreasing order: C. krusei > C. albicans 5997 > C. dubliniensis > C. glabrata 50R > C. parapsilosis > C. albicans 15R > C. glabrata 8235 > C. tropicalis. Together, these results showed that various species of Candida presented different concentrations of glucosylceramide and mannose-inositol phosphoceramide. The role of these GSLs and steryl-glucoside in the Candida pathogenisis will be discussed.
Supported by FAPESP, CAPES and CNPq
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