ANALYSIS OF THE ADAPTIVE OXIDATIVE STRESS-RESPONSE OF CANDIDA-ALBICANS

Treatment of Candida albicans with low concentrations of either hydrog en peroxide or menadione (a superoxide generating agent) induces an ad aptive response which protects cells from the lethal effects of a subs equent challenge with higher concentrations of these oxidants. Pre-tre atment with either menadione or hydrogen peroxide is protective agains t cell killing by either oxidant. This suggests that the pathogenic ye ast C. albicans (unlike the budding yeast Saccharomyces cerevisiae whi ch has separate responses) possesses an adaptive response that respond s to both these oxidants. In addition, we found that C. albicans showe d a greater level of resistance to oxidants, both H2O2 and redox-cycli ng agents, compared to that observed with S, cerevisiae. In an attempt to characterise the oxidative stress response in more detail we have analysed the effect of oxidants on the activities of a number of enzym es with known antioxidant activity.