Two Clinical Isolates of Candida glabrata Exhibiting Reduced Sensitivity to Amphotericin B Both Harbor Mutations in ERG2

Two novel isolates of Candida glabrata exhibiting reduced sensitivity to amphotericin B ( MIC, 8 mu g ml(-1)) were found to be ERG2 mutants, wherein Delta(8)-sterol intermediates comprised >90% of the total cellular sterol fraction. Both harbored an alteration at Thr(121) in ERG2; the corresponding residue (Thr(119)) in Saccharomyces cerevisiae is essential for sterol Delta 8-Delta 7 isomerization. This constitutes the first report of C. glabrata harboring mutations in ERG2 and exhibiting reduced sensitivity to amphotericin B.