Evaluation of a Most Probable Number Quantitation System with a Modified AATCC Test Method 100 for Measuring Fungal Growth

Industrial testing for bacterial growth on commercial substrates is highly efficient, with high-throughput means for quantifying growth. However, current antifungal testing is mostly subjective, with quantitative tests reliant on labor-intensive colony counting. We evaluated the use of a commercially available most probable number (MPN) system for quantifying growth of mold in a modified version of the AATCC Test Method (TM) 100. Using the MPN system, we were able to detect up to a 3.7-fold log reduction in mold growth between antifungal treated and untreated fabric samples. Using agar plate counts in parallel, we reproduced the trends observed using the MPN system. The trends in log reduction of growth correlated well and confirm that the MPN system satisfactorily substitutes for plate counts in evaluating antimicrobial technologies.