Behaviour of Listeria monocytogenes isolates through gastro-intestinal tract passage simulation, before and after two sub-lethal stresses
Behaviour of Listeria monocytogenes isolates through gastro-intestinal tract passage simulation, before and after two sub-lethal stresses
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DOI：
10.1016/j.fm.2011.10.001
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发表时间：
2012-05-01
影响因子：
5.3
通讯作者：
Teixeira, P.
中科院分区：
文献类型：
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作者：
Barbosa, J.;Borges, S.;Teixeira, P.
研究了先前暴露于亚致死酸性和渗透胁迫对单核细胞增生李斯特菌在暴露于胃肠道模拟期间的存活的影响。选择从奶酪中分离出的六种单增李斯特菌菌株，并将其暴露于高盐浓度或酸性条件下，并比较它们在快速和慢速消化中的活力。结果表明，(i) 所有分离株对暴露于酸性环境比渗透亚致死条件更敏感 (ii) 观察到两种消化类型之间存在显着差异 (p < 0.05)；在慢速消化中，所有测试分离株的对数减少均较高 (iii) 所有分离株在两种类型的消化中都在胆汁盐存在的情况下受到抑制 (iv) 在暴露于渗透或酸性应激后，未观察到快速和慢速消化之间的差异 (p > 0.05) (v) 在暴露于渗透压或酸性应激后，在通过胃肠道模拟的过程中观察到更高的细胞失活 (p < 0.001) 以及 (vi) 既不渗透也不暴露于酸性应激酸性亚致死应激赋予对模拟胃肠道条件的抵抗力。 (C) 2011 Elsevier Ltd. 保留所有权利。
The effects of previous exposure to sub-lethal acidic and osmotic stresses on the survival of Listeria monocytogenes during exposure to gastro-intestinal (GI) tract simulation, was investigated. Six L monocytogenes strains isolated from cheeses were selected and exposed to high salt concentrations or acidic conditions and their viability compared in quick and slow digestions. The results demonstrated that (i) all isolates were more sensitive to the exposure to acidic than to osmotic sub-lethal conditions (ii) significant differences (p < 0.05) between the two types of digestion were observed; in slow digestion, the log reduction was higher for all the tested isolates (iii) all isolates were inhibited in the presence of bile salts for both types of digestion (iv) differences between quick and slow digestion were not observed (p > 0.05) after exposure to either osmotic or acidic stress (v) a higher cellular inactivation (p < 0.001) was observed during the passage through the GI tract simulation after exposure to osmotic than to acidic stresses and (vi) neither osmotic nor acidic sub-lethal stresses conferred resistance to simulated GI tract conditions. (C) 2011 Elsevier Ltd. All rights reserved.