Fig 10. Effect of fre8Δ/Δ mutations on fungal invasion of the kidney and virulence in a mouse model of disseminated candidiasis.

Mice were infected with either WT SC5314 or the isogenic fre8Δ/Δ mutant by the lateral tail vein injection as described in Materials and Methods. (A) Following 7 days of infection, kidneys were harvested from surviving mice and analyzed for fungal morphology by PAS staining as in Materials and Methods. Shown are the individual kidney sections from 4 independent mice for each group. (B) Quantification of the hyphal length from WT versus fre8Δ/Δ fungi invading the kidney. Results represent 375 and 503 fungal cells from 6 WT-infected and 4 fre8Δ/Δ-infected mice, respectively. The short oblong morphological forms that were prevalent with fre8Δ/Δ cells were included in this analysis, but not the occasional rounded yeast-forms. The difference in hyphal length between WT and fre8Δ/Δ cells is statistically significant as determined by t-test, ***p<0.0001. (C) Survival curves of infected mice including 10 mice from each group. There was no statistical difference between mice infected with WT C. albicans versus the fre8Δ/Δ mutant as determined by the log-rank (Mantel-Cox) test.