GRADUAL SOLUBILIZATION OF CANDIDA, CELL-WALL BETA-GLUCAN BY OXIDATIVE-DEGRADATION IN MICE

Candida spp. is a medically important fungi which induces disseminated candidiasis and candidemia in hospitalized immunocompromised patients . The cell wall of Candida is mainly composed of two polysaccharides, mannan and beta-glucan, and at least part of beta-glucan is basically insoluble in H2O or NaOH, We became interested in when and how particu late beta-glucan changes to the soluble form. However, the Fate of wal l components has not been examined in detail. In this study, modificat ion and solubilization of the cell wall beta-glucan were analyzed in v ivo and in vitro. Cells of Candida, intravenously administered to mice (1 mg/mouse), were immediately deposited mainly in liver as determine d by H-3-labeled cells. beta-Glucans were detected in these mice for a t least for 6 months by the beta-glucan specific assay. During this pe riod, the insoluble cell wall beta-glucan was gradually solubilized in these organs, probably by oxidative stress of macrophages, Candida ce lls and particulate beta-glucans were also gradually solubilized in vi tro using sodium hypochlorite solution: but part of the cell wall beta -glucan was still insoluble even after treatment with concentrated hyp ochlorite solution for one day at room temperature. These findings str ongly suggested that the fungal cell wall beta-glucans were quite resi stant to oxidative metabolism in vivo and in vitro, and thus deposited for quite long period in the host. (C) 1998 Federation of European Mi crobiological Societies. Published by Elsevier Science B.V. All rights reserved.