Heteroresistance to itraconazole promotes different banding patterns following PFGE and reduction of ergosterol content. (A) Banding patterns of original strains L135/03 and L27/01 and their heteroresistant clones following 1% PFGE. Lane 1, PFGE size marker (SM), 0.225 to 2.2 Mb S. cerevisiae chromosomal DNA. Arrows indicate the different bands observed between the original and heteroresistant cells. (B) Reduction in ergosterol content of original strains L135/03 and L27/01 and their heteroresistant clones following a 1-h treatment with itraconazole. Results are expressed in micrograms/milliliter. Statistically significant differences between original and heteroresistant cells and between cells treated with and without itraconazole are represented by the horizontal lines (P < 0.05). Statistically significant differences between original strains L135/03 and L127/01 subjected to the same treatment are represented by an asterisk (P < 0.05). Data represent the means ± SE from two independent experiments consisting of triplicate assays. ITC, itraconazole; O, original; H, heteroresistant.