Escape of Candida from caspofungin inhibition at concentrations above the MIC (Paradoxical effect) accomplished by increased cell wall chitin;: Evidence for β-1,6-glucan synthesis inhibition by caspofungin

Concentrations above the MIC of caspofungin allow growth of some Candida isolates. A strain demonstrating paradoxical growth was grown in the presence and absence of caspofungin, and the cell wall content was analyzed. beta-1,3-Glucan declined 81% in the presence of caspofungin, as expected. beta-1,6-Glucan declined 73%. Chitin increased 898%, demonstrating a mechanism for paradoxical growth-a rapid shift in the key polymer.