Pretreatment of C. albicans increases virulence in the mouse model and leads to more-rapid filamentation. (A) C. albicans cells were treated with SNP+SHAM for 18 h and then washed in PBS prior to injection via the tail vein. Weight loss, fungal burden, and outcome score were calculated as described in Materials and Methods. *, P < 0.05. (B) Cross-section from kidney infected with untreated wild-type or SNP+SHAM-pretreated cells, both stained with hematoxylin and eosin (Hem + Eos; bar, 50 µm) to emphasize locations of immune infiltration (white arrows) or periodic acid-Schiff reagent (PAS; bar, 20 µm) to highlight C. albicanscells (black arrows). (C) Wild-type cells were treated with 1 mM SNP–0.5 mM SHAM for 18 h and then washed in PBS and transferred to serum-containing medium at 37°C. Representative examples of filamentation in wild-type untreated and SNP+SHAM-pretreated cells after 90 min. (D) The percentages of filamentous cells were calculated in cells pretreated with SNP, SHAM, or SNP+SHAM, washed, and grown for 90 min as described for panel C (n = 3). (E) Wild-type and aox2Δ aox1Δ mutant cells were treated with 1 mM SNP–0.5 mM SHAM for 18 h and then washed in PBS and transferred to serum-containing medium at 37°C for 90 min before assessment. Graphs show means ± standard deviations. Three independent experiments were performed for each analysis. Student's t test was used to compare groups. *, P < 0.01.
|