Table 1.
Candida albicans strains used in this study.
Table 2.
Synergistic antifungal activity between posaconazole and caspofungin or FK506 against C. albicans drug susceptible or resistant strains.
Figure 1.
Efficacy of posaconazole and caspofungin against C. albicans infection.
Five male CD1 mice (4–5 weeks-old) per group were infected with 106 cells of C. albicans SC5314, azole-resistant isolate 12–99, or echinocandin-resistant isolate 89, followed by treatment with placebo (PBS), posaconazole (PSC; 2 mg/kg), caspofungin (CSF; 0.1 mg/kg), or PSC (2 mg/kg) plus CSF (0.1 mg/kg). The PSC was administered via oral gavage, while PBS and CSF were administered via intraperitoneal injection at 4, 24, 48, and 72 hr post infection. Survival of the animals was monitored for up to 35 days.
Figure 2.
Efficacy of posaconazole and FK506 against C. albicans infection.
Ten male CD1 mice (4–5 weeks-old) per group were infected with 106 cells of C. albicans SC5314, azole-resistant isolate 12–99, or echinocandin-resistant isolate 89, followed by treatment with placebo (PBS), posaconazole (PSC; 0.5 mg/kg), FK506 (0.5 mg/kg), or PSC (0.5 mg/kg) plus FK506 (0.5 mg/kg). The PSC was administered via oral gavage, while PBS and FK506 were administered via intraperitoneal injection at 4, 24, 48, and 72 hr post inoculation. Survival of the animals was monitored for up to 18 days.
Figure 3.
Confirmation of C. albicans FKS1-1 mutants with the S645Y mutation.
(A) Genomic DNA from SC5314 (wild-type), the FKS1-1 mutants (YC734 and YC736), and isolate 89 were PCR amplified with primers JC584/JC585 to detect a 410 bp (1810∼2220) product of the CaFKS1 gene, and then sequenced with primer JC584. Nucleotide 1934 of the CaFKS1 gene is labeled green. The C1934A mutation is present in FKS1-1 mutants derived from SC5314 and in the clinical isolate 89, but absent in SC5314. Nucleotide 1938 of the CaFKS1 gene is labeled purple. An A1938G silent mutation is present in the FKS1-1 mutants, but not in SC5314 or isolate 89. (B)&(C) The 410 bp PCR product of the CaFKS1 gene was amplified from genomic DNA from SC5314, FKS1-1 mutants (YC734 and YC736), and isolate 89, and digested with PflFI (B) or MseI (C) to confirm the C1934A or A1938G mutations are present and to confirm the mutations occurred in both alleles of the gene.
Figure 4.
In vitro phenotypes and the in vivo efficacy of posaconazole combined with either caspofungin or FK506 against C. albicans FKS1-1 mutant.
Cells were grown overnight in YPD at 30°C, 5-fold serially diluted, spotted onto YPD medium containing an echinocandin (A) or an azole (B) at the concentrations indicated, and incubated at 37°C for 48 hr. The efficacy of posaconazole (2 mg/kg) and caspofungin (0.1 mg/kg) (C) or posaconazole (0.5 mg/kg) and FK506 (0.5 mg/kg) (D) against the C. albicans FKS1-1 mutant (YC734). The experimental procedures are similar to those described in the legend to Figure 1, except that the survival of the animals was monitored for up to 21 days.