Effect of rpoS on the survival and gene expression of Salmonella Enteritidis in low water activity foods
Effect of rpoS on the survival and gene expression of Salmonella Enteritidis in low water activity foods
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DOI：
10.1111/jfs.13039
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发表时间：
2023-01
影响因子：
2.4
通讯作者：
Zhuolin Ma;Shaoting Li;Weiying Xu;Yingqi Chen;Ziying Lu;Rong Fu;Xinyi He;Hongmei Zhang
中科院分区：
文献类型：
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作者：
Zhuolin Ma;Shaoting Li;Weiying Xu;Yingqi Chen;Ziying Lu;Rong Fu;Xinyi He;Hongmei Zhang
本研究评估了在干燥 24 小时和储存 7 天的低水分活度 (Aw) 食品中，转录调节因子 RpoS 对细菌存活、对模拟胃肠道条件的耐受性以及野生型 (WT) 和 rpoS 缺失 (ΔrpoS) 肠炎沙门氏菌 CICC 21482 中的应激抗性基因表达的影响。 ΔrpoSstrain 是通过使用自杀质粒进行等位基因交换而产生的。在模拟胃液和肠液存在的情况下，将细菌接种到生姜粉、脱脂奶粉和巧克力粉中，并测量存活率。使用实时定量聚合酶链反应测量基因表达。 ΔrpoSstrain 对干燥应力的抵抗力低于 WT 菌株。细菌对胃肠道条件的耐受性因食物成分而异，高脂肪和蛋白质含量可增强肠炎沙门氏菌在胃肠道条件下的存活率。此外，在低Aw条件下，rpoS与食品底物中offadA的表达呈弱相关，而与grpE、otsA、otsB、dnaK、proV、rpoH和sigDE的表达呈强相关。本研究阐明了rpoS在干燥应激中的作用，并为预防和控制低Aw食品中沙门氏菌污染奠定了基础。
This study evaluated the effect of the transcriptional regulator RpoS on bacterial survival, tolerance to simulated gastrointestinal conditions, and the expression of stress resistance genes in wild‐type (WT) andrpoS‐deletion (ΔrpoS)SalmonellaEnteritidis CICC 21482 in low water activity (Aw) foods at 24 hr of drying and 7 days of storage. The ΔrpoSstrain was produced by allelic exchange using a suicide plasmid. Bacteria were inoculated into ginger powder, nonfat milk powder, and chocolate powder in the presence of simulated gastric and intestinal fluids, and survival was measured. Gene expression was measured using real‐time quantitative polymerase chain reaction. The ΔrpoSstrain was less resistant to desiccation stress than the WT strain. The bacterial tolerance to gastrointestinal conditions varied depending on food composition, and high‐fat and protein content enhanced the survival ofS.Enteritidis in the gastrointestinal conditions. In addition, under lowAwconditions,rpoSwas weakly correlated with the expression offadAbut strongly correlated with the expression ofgrpE,otsA,otsB,dnaK,proV,rpoH, andsigDEin food substrates. This study elucidates the role ofrpoSin desiccation stress and serves as the basis for preventing and controllingSalmonellacontamination in lowAwfoods.