Similar dilutions in either Tween-20 (0.5%), dimethyl sulfoxide (DSMO, 5%), or ethanol (100%) were transferred to sterile microtiter plates (honeycomb plates with 100 wells). Three parallel dilution series were used with 100 µL in each well. The microtiter plates were mounted in a Bioscreen C (Oy Growth Curves Ab Ltd., Helsinki, Finland), an automated growth curve analysis system, programmed to measure absorbance at 600 nm (abs 600 nm) at regular time intervals at 37 ± 0.1 °C. Prior to each measurement, the plates were shaken for 10 s (default setting). Growth curves of both strains were recorded. Time-to-detection (TTD) were defined as ABS600nm = 0.2. Lack of absorbance above 0.2 were defined as growth inhibition.