Nature and Development of Phenotypic Resistance to Amphotericin B in Candida albicans

Abstract

Publisher Summary Resistance to amphotericin in Candida albicans begins to increase when cultures pass into the stationary phase of growth and may reach very high values if incubation continues in the absence of an external source of carbon and energy, especially at an acid pH value and in the absence of sources of reducing potential. The evidence that has accumulated in the course of the studies mentioned in the chapter indicates that this resistance can be attributed to the development in the wall of a barrier to the penetration of the antibiotic to target sites in the cytoplasmic membrane. This barrier involves (1→3)-β-glucan chains and its action in the impeding passage of the antibiotic increases as these chains increase in length and form a tightly cross-linked network within the cell wall. Rupture of β-chains by the action of β-glucanases decreases resistance, while blocking chain extension or increasing chain instability by the incorporation of glucose analogues prevents further increase in the resistance.