THE FUNGICIDAL EFFECT OF HUMAN LACTOFERRIN ON CANDIDA-ALBICANS AND CANDIDA-KRUSEI

Five oral isolates each of Candida albicans and Candida krusei were st udied for their sensitivity to the fungicidal effect of human lactofer rin. Significant inter- and intraspecies variations were observed and with most isolates the sensitivity of C. krusei to lactoferrin was gre ater than that of C. albicans. Fungicidal activity of lactoferrin was dose-dependent and observable only with the iron-free form of the mole cule (apo-lactoferrin). Iron-saturated lactoferrin was ineffective aga inst all isolates. Supernatant protein assays and scanning electron mi croscopy indicated cell surface alterations-leakage of proteins and fo rmation of surface blebs-only in those Candida isolates that were sens itive to apo-lactoferrin. As lactoferrin is a common, non-immune, muco sal defence protein, its varying mode of action against C. albicans an d C. krusei may be related to their different oral carriage rates.