ATCC 6538 was not completely inactivated in the most severe HPP condition tested (600 MPa/30 min) and was more barotolerant to the different treatments than the enterotoxic strains, which is in agreement with a recent study (Baptista et al., 2015) in which this strain was able to resist 10 successive HPP cycles at 600 MPa/ 30 min. In this study, under the condition 600 MPa/30 min, the strains 2153 MA and 2065 MA were inactivated to the limit of
detection (LOD) of the method (1 CFU mL-1). However, the strain
2065 MA was only able to withstand 4 consecutive cycles of pres- surization at 600 MPa/15 min although the strain 2153 MA was capable to withstand the 10 consecutive cycles at this condition. None of the three strains showed resistance development during the 10 HPP consecutive cycles.
solution in a rotatory evaporator under vacuum.