Isothermal microcalorimetry: A novel method for real-time determination of antifungal susceptibility of Aspergillus species

Abstract

We evaluated microcalorimetry for real-time susceptibility testing of Aspergillus spp. based on growth-related heat production. The minimal heat inhibitory concentration (MHIC) for A. fumigatus ATCC 204305 was 1mg/L for amphotericin B, 0.25mg/L for voriconazole, 0.06mg/L for posaconazole, 0.125mg/L for caspofungin and 0.03mg/L for anidulafungin. Agreement within two 2-fold dilutions between MHIC (determined by microcalorimetry) and MIC or MEC (determined by CLSI M38A) was 90% for amphotericin B, 100% for voriconazole, 90% for posaconazole and 70% for caspofungin. This proof-of-concept study demonstrated the potential of isothermal microcalorimetry for growth evaluation of Aspergillus spp. and real-time antifungal susceptibility testing. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.