Development of resistance in Cronobacter sakazakii ATCC 29544 to thermal and nonthermal processes after exposure to stressing environmental conditions
Development of resistance in Cronobacter sakazakii ATCC 29544 to thermal and nonthermal processes after exposure to stressing environmental conditions
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DOI：
10.1111/j.1365-2672.2011.05218.x
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发表时间：
2012-03-01
影响因子：
4
通讯作者：
Pagan, R.
中科院分区：
文献类型：
--
作者：
Arroyo, C.;Cebrian, G.;Pagan, R.
目的：研究食品加工环境中可能遇到的不同亚致死应激条件下，阪崎慢杆菌ATCC-29544细胞对热、脉冲电场、加压超声(MS)和紫外线(UV-C)处理的反应。方法：将处于静止生长期的阪崎慢杆菌细胞(30℃，24 h)暴露于酸(pH 4 5，1h)、碱性(pH 9 0，1 h)、渗透压(5%NaC l，1 h)、氧化(0.5 mmol L(-1)H_2O_2，1 h)、热(47.5摄氏度，1小时)和冷(4摄氏度，4小时)应激条件，并受到随后的挑战：热(60摄氏度)，PEF(25千伏厘米)1，35摄氏度)，MS(117微米，200千帕，35摄氏度)和UV-C光(88.55毫瓦厘米(-2)，25摄氏度)处理。在暴露于任何一种胁迫后，不同技术对阪崎肠杆菌的灭活动力学没有改变。亚致死应激和致死处理的组合具有保护作用：热休克-热、热休克-PEF和酸性pH-PEF。相反，碱性休克使细胞对热和UV-C处理敏感，渗透休克对热处理敏感，氧化休克对UV-C处理敏感。热休克细胞受热处理的适应性反应最大，使99.9%的种群失活时间增加1.6倍。结论：阪崎慢杆菌对热保存技术和非热保存技术的抵抗力可因先前暴露在应激条件下而增加或减少。研究的意义和影响：该结果有助于理解这种新兴病原体对传统和新型保存技术的抵抗力的生理学。
Aims: The objective was to study the response of Cronobacter sakazakii ATCC 29544 cells to heat, pulsed electric fields (PEF), ultrasound under pressure (Manosonication, MS) and ultraviolet light (UV-C) treatments after exposure to different sublethal stresses that may be encountered in food-processing environments.Methods and Results: Cronobacter sakazakii stationary growth-phase cells (30 degrees C, 24 h) were exposed to acid (pH 4 5, 1 h), alkaline (pH 9 0, 1 h), osmotic (5% NaCl, 1 h), oxidative (0.5 mmol l(-1) H2O2, 1 h), heat (47.5 degrees C, 1 h) and cold (4 degrees C, 4 h) stress conditions and subjected to the subsequent challenges: heat (60 degrees C), PEF (25 kV cm) 1, 35 degrees C), MS (117 mu m, 200 kPa, 35 degrees C) and UV-C light (88.55 mW cm(-2), 25 degrees C) treatments. The inactivation kinetics of C. sakazakii by the different technologies did not change after exposure to any of the stresses. The combinations of sublethal stress and lethal treatment that were protective were: heat shock-heat, heat shock-PEF and acid pH-PEF. Conversely, the alkaline shock sensitized the cells to heat and UV-C treatments, the osmotic shock to heat treatments and the oxidative shock to UV-C treatments. The maximum adaptive response was observed when heat-shocked cells were subjected to a heat treatment, increasing the time to inactivate 99.9% of the population by 1.6 times.Conclusions: Cronobacter sakazakii resistance to thermal and nonthermal preservation technologies can increase or decrease as a consequence of previous exposure to stressing conditions.Significance and Impact of the Study: The results help in understanding the physiology of the resistance of this emerging pathogen to traditional and novel preservation technologies.