Development of resistance in Cronobacter sakazakii ATCC 29544 to thermal and nonthermal processes after exposure to stressing environmental conditions

摘要: Aims:  The objective was to study the response of Cronobacter sakazakii ATCC 29544 cells heat, pulsed electric fields (PEF), ultrasound under pressure (Manosonication, MS) and ultraviolet light (UV-C) treatments after exposure different sublethal stresses that may be encountered in food-processing environments. Methods Results: Cronobacter stationary growth-phase (30°C, 24 h) were exposed acid (pH 4·5, 1 h), alkaline 9·0, osmotic (5% NaCl, oxidative (0·5 mmol l−1 H2O2, heat (47·5°C, 1 h) cold (4°C, 4 h) stress conditions subjected subsequent challenges: (60°C), PEF (25 kV cm−1, 35°C), MS (117 μm, 200 kPa, 35°C) UV-C (88·55 mW cm−2, 25°C) treatments. inactivation kinetics C. sakazakii by technologies did not change any stresses. combinations lethal treatment protective were: shock–heat, shock–PEF pH–PEF. Conversely, shock sensitized treatments, maximum adaptive observed when heat-shocked a treatment, increasing time inactivate 99·9% population 1·6 times. Conclusions: Cronobacter resistance thermal nonthermal preservation can increase or decrease as consequence previous stressing conditions. Significance Impact Study:  results help understanding physiology this emerging pathogen traditional novel technologies.