Heat and pulsed electric field resistance of pigmented and non-pigmented enterotoxigenic strains of Staphylococcus aureus in exponential and stationary phase of growth
Heat and pulsed electric field resistance of pigmented and non-pigmented enterotoxigenic strains of Staphylococcus aureus in exponential and stationary phase of growth
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DOI：
10.1016/j.ijfoodmicro.2007.07.051
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发表时间：
2007-09-30
影响因子：
5.4
通讯作者：
Manas, P.
中科院分区：
文献类型：
--
作者：
Cebrian, G.;Sagarzazu, N.;Manas, P.
四个肠致病性金黄色葡萄球菌菌株（具有不同的色素含量）的热和脉冲电场（PEF）治疗的生存，并增加与进入稳定期相关的加工应力的阻力进行了检查。获得了细胞在静止期和指数生长期对热（58 ℃）和对PEF（26 kV/cm）的存活曲线。然而，在四种菌株中检测到对热处理的抗性的广泛变化，在58 ° C（D-58 ° C）下的十进制还原时间值在0.93至0.20分钟的范围内，对PEF的抗性非常相似。稳定期耐热性的提高与类胡萝卜素色素含量的增加相一致。金黄色菌落。然而，最耐热（色素）和最热敏感（非色素）的细胞株在指数生长中期表现出相似的耐热性和PEF。因此，进入生长稳定期后，色素菌株的耐热性增加更为显著。在厌氧条件下的恢复，特别是提高了生存的非色素菌株的热处理。具有缺陷的σ B活性的菌株CECT 4630显示出低耐热性、低色素沉着和在稳定期中耐热性的降低的增加。这些结果表明，S.金黄色葡萄球菌在稳定期的类胡萝卜素含量与菌株的类胡萝卜素含量呈正相关。对脉冲电场的耐受性的发展不太相关，与类胡萝卜素含量无关。(C)2007 Elsevier B. V.保留所有权利。
The survival of four enterotoxigenic strains of Staphylococcus aureus (with different pigment content) to heat and to pulsed electric fields (PEF) treatments, and the increase in resistance to both processing stresses associated with entrance into stationary phase was examined. Survival curves to heat (58 degrees C) and to PEF (26 kV/cm) of cells in the stationary and in the exponential phase of growth were obtained. Whereas a wide variation in resistance to heat treatments was detected amongst the four strains, with decimal reduction time values at 58 degrees C (D-58 degrees C) ranging from 0.93 to 0.20 min, the resistance to PEF was very similar. The occurrence of a higher tolerance to heat in stationary phase was coincident with a higher content in carotenoid pigmentation in S. aureus colonies. However, cells of the most heat resistant (pigmented) and the most heat sensitive (non-pigmented) strains in the mid-exponential phase of growth showed similar resistance to heat and to PEF. Therefore the increase in thermotolerance upon entrance into stationary phase of growth was more marked for the pigmented strains. Recovery in anaerobic conditions particularly enhanced survival to heat treatments in a non-pigmented strain. Strain CECT 4630, which possess a deficient sigma B activity, showed low heat resistance, low pigmentation, and reduced increase in thermotolerance in stationary phase. These results indicate that the magnitude of the development of a higher heat resistance in S. aureus in stationary phase is positively related to the carotenoid content of the strain. The development of tolerance to pulsed electric field was less relevant and not linked to the carotenoid content. (C) 2007 Elsevier B.V. All rights reserved.