Spectrophotometric method of inoculum preparation for the in vitro susceptibility testing of filamentous fungi

Abstract

Homogeneous inoculum suspensions of 29 isolates of clinically important filamentous fungi were adjusted with a spectrophotometer (530 nm) to obtain standardized preparations containing 1 x 10(6) to 5 x 10(6) CFU/ml. Colony counts (CFU per milliliter) of 1 x 10(6) to 5 x 10(6) were achieved on three different days for isolates of Aspergillus spp., Pseudallescheria boydii, and Sporothrix schenckii (80% +/- 2% transmission), and colony counts of 7 x 10(5) to 2.9 x 10(6) (70% +/- 2% transmission) were achieved for Mucor spp. and Rhizopus spp.