Comparison of posaconazole and voriconazole in vitro killing against Candida krusei.
The in vitro activity of posaconazole and voriconazole was evaluated by MIC, minimum fungicidal concentration (MFC), and time-kill methods. MFCs were determined for 15 Candida krusei and time-killing curves for 5 of these isolates. MFCs were obtained transferring 100 microL from clear MIC wells onto Sabouraud dextrose agar. Time-kill studies were performed in RPMI 1640 medium (5 mL, inoculum approximately 10(5) colony-forming unit [CFU]/mL). Geometric mean (GM) MIC and GM-MFC were 0.2 and 0.72 mg/L for posaconazole and 0.4 and 2.64 mg/L for voriconazole. The killing rate was isolate and concentration dependent; reductions in CFUs start at >or=0.12 mg/L (posaconazole) and >or= 0.5 mg/L (voriconazole). The mean time to reach a 90% growth reduction was 41.5+/-14.2 h (8 mg/L posaconazole) and 48.7+/-61.3 h (32 mg/L voriconazole). By time kill, a 99% killing rate was not reached by either agent. Both methods demonstrated that posaconazole (more active and greater killing rate) and voriconazole have fungicidal activity against C. krusei.
Cantón
Emilia
E
Unidad de Microbiología Experimental, Centro de Investigación, Hospital Universitario La Fe, 46009 Valencia, Spain. canton_emi@gva.es
Pemán
Javier
J
Valentín
Amparo
A
Bosch
Maria
M
Espinel-Ingroff
Ana
A
Gobernado
Miguel
M
D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000254:growth & development* / Q000302:isolation & purification; D002177:Candidiasis / Q000382:microbiology; D003470:Culture Media; D025141:Drug Resistance, Fungal; D016469:Fungemia / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D011743:Pyrimidines / Q000494:pharmacology*; D013997:Time Factors; D014230:Triazoles / Q000494:pharmacology*; D065819:Voriconazole
D000935:Antifungal Agents; D003470:Culture Media; D011743:Pyrimidines; D014230:Triazoles; C101425:posaconazole; D065819:Voriconazole