Effect of amphotericin B alone or in combination with rifampicin on phagocytosis of Candida species by human polymorphonuclear leukocytes.

The influence of amphotericin B and rifampicin alone and in combination on the killing of Candida albicans, Candida tropicalis and Cryptococcus neoformans by human polymorphonuclear leukocytes was investigated in vitro. Granulocytes were harvested from the blood of healthy volunteers and resuspended with the above mentioned fungi. After 6 hours, 81.5% of C. albicans, 97% of C. tropicalis but only 34% of C. neoformans were killed. The activity of amphotericin B against C. albicans and C. tropicalis was better in granulocyte-free medium. A synergism between amphotericin B and rifampicin towards Candida could be detected. It was also demonstrated in the presence of polymorphonuclear leukocytes with a factor > 1 log in reduction of colony count. However, whether granulocytes were present or not, rifampicin (4 mcg/mL) alone did not exert any influence on growth of Candida.