A fast, practical and reproducible procedure for the standardization of the cell density of an Aspergillus suspension

The progressive increase of invasive disease and reports of resistance among Aspergillus species emphasizes the need for reproducible antifungal susceptibility testing. Inoculum standardization is a crucial step in such procedures. The objective of this study was to develop a fast and precise method of evaluating the cell density of an Aspergillus spore suspension, as an alternative to spectrometric readings or cell-counting with a haemocytometer. Densimat (bioMerieux) is a portable photometer that shows a good correlation with spectrometric readings and can advantageously replace the cumbersome, time-consuming method of cell-counting. Thus, Densimat brings significant improvement to the reproducibility and feasibility of standardization of a fungal inoculum.