Effects of lactic acid stress with lactic acid adaptation on the survival and expression of virulence-related genes in Escherichia coli O157:H7
Effects of lactic acid stress with lactic acid adaptation on the survival and expression of virulence-related genes in Escherichia coli O157:H7
复制标题
乳酸应激和乳酸适应对大肠杆菌 O157:H7 毒力相关基因的存活和表达的影响
DOI：
10.1111/jfs.12701
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发表时间：
2019
影响因子：
2.4
通讯作者：
Jiang Yun
中科院分区：
文献类型：
--
作者：
Yu Lanlin;Ji Saisai;Yu Jinlong;Fu Wenjing;Zhang Lin;Li Jiaolong;Gao Feng;Jiang Yun
本研究旨在研究乳酸胁迫与酸适应对大肠杆菌O157：H7(菌株CICC21530、89、95、112、109和J42)存活和毒力相关基因表达的影响。结果表明，暴露于pH 3.5时，大肠埃希氏菌的存活率下降，其中109、112和J42菌株的耐酸性较强。与非应激细胞相比，大多数菌株暴露于pH 3.5后，毒力相关基因的表达下降。此外，除CICC21530和J42外，大多数菌株的耐酸能力都有所提高。与未适应的细胞相比，大多数酸适应的细胞毒力表达降低或无明显变化。O157：H7菌株的存活与毒力相关基因的表达无明显关系。然而，酸适应菌株的耐酸能力是可变的，一些酸适应增加了菌株的存活和毒力相关基因的表达，这仍然可能威胁食品安全。本研究评估了乳酸胁迫和酸适应对大肠杆菌O157：H7毒力相关基因存活和表达的影响。酸适应可增强某些菌株的存活率和毒力表达，对酸性食品在加工和储存过程中的安全性构成威胁。此外，在监测和控制E的过程中，应注意耐酸菌株的耐酸性变化。环境和食品中的大肠杆菌O157：H7，有利于其科学有效的风险评估和控制。
This study was aimed to investigate the effects of lactic acid stress with acid adaptation on the survival and expression of virulence‐related genes inEscherichia coliO157:H7 (strains CICC21530, 89, 95, 112, 109, and J42).E.coliwere subjected to acid adaption (pH 5.0) for 1–4 hr and then exposed to acid stress (pH 3.5) for 30–120 min. Results showed that exposure to pH 3.5 decreased the survival ofE.colistrains, in which strains 109, 112, and J42 had stronger acid resistance. The expression of virulence‐related genes of most strains decreased after exposure to pH 3.5 compared with nonstressed cells. In addition, acid adaptation increased the acid resistance of most strains, except for CICC21530 and J42. And the virulence expression of most acid‐adapted cells decreased or showed no significant changes compared with nonadapted cells. There were no obvious relationships between the survival and expression of virulence‐related genes inE.coliO157:H7 strains. However, variable acid resistance of acid‐adapted strains was existed, and some acid adaptation increased the strain survival and expression of virulence‐related genes, which may still threaten food safety.Practical ApplicationsThis study evaluated the effects of lactic acid stress with acid adaptation on the survival and expression of virulence‐related genes inEscherichia coliO157:H7. Acid adaptation could enhance the survival and virulence expression of some strains, which will threaten the safety of acidic food during processing and storage. Furthermore, variable acid resistance of acid‐adapted strains should be noticed in surveillance and control ofE. coliO157:H7 in environment and food, which is beneficial for its scientific and effective risk assessment and control.