Thermal death potentiation by amphotericin B in Cryptococcus neoformans and its dependence on pre-incubation temperature.

Thermal death of Cryptococcus neoformans in the presence of amphotericin B was strongly dependent upon the temperature of pre-incubation. The entropy coefficient, that is, the increase in entropy of activation of thermal death per square unit concentration of the drug in the medium, was 35 times higher after pre-incubation at 25 degrees C than at 39 degrees C. This means that C. neoformans cells grown at lower temperatures were much more sensitive to the temperature-dependent fungicidal effect of amphotericin B.