Quadram Institute Bioscience, Norwich Research Park, James Watson Road, Norwich, UK; University of East Anglia, Norwich Research Park, Norwich, UK.
Quadram Institute Bioscience, Norwich Research Park, James Watson Road, Norwich, UK.
Food Microbiol. 2023 Jun;112:104237. doi: 10.1016/j.fm.2023.104237. Epub 2023 Feb 8.
Non-Typhoidal Salmonella (NTS) continues to be a leading cause of foodborne illness worldwide. Food manufacturers implement hurdle technology by combining more than one approach to control food safety and quality, including preservatives such as organic acids, refrigeration, and heating. We assessed the variation in survival in stresses of genotypically diverse isolates of Salmonella enterica to identify genotypes with potential elevated risk to sub-optimal processing or cooking. Sub-lethal heat treatment, survival in desiccated conditions and growth in the presence of NaCl or organic acids were investigated. S. Gallinarum strain 287/91 was most sensitive to all stress conditions. While none of the strains replicated in a food matrix at 4 °C, S. Infantis strain S1326/28 retained the greatest viability, and six strains exhibited a significantly reduced viability. A S. Kedougou strain exhibited the greatest resistance to incubation at 60 °C in a food matrix that was significantly greater than S. Typhimurium U288, S Heidelberg, S. Kentucky, S. Schwarzengrund and S. Gallinarum strains. Two isolates of monophasic S. Typhimurium, S04698-09 and B54Col9 exhibited the greatest tolerance to desiccation that was significantly more than for the S. Kentucky and S. Typhimurium U288 strains. In general, the presence of 12 mM acetic acid or 14 mM citric acid resulted in a similar pattern of decreased growth in broth, but this was not observed for S. Enteritidis, and S. Typhimurium strains ST4/74 and U288 S01960-05. Acetic acid had a moderately greater effect on growth despite the lower concentration tested. A similar pattern of decreased growth was observed in the presence of 6% NaCl, with the notable exception that S. Typhimurium strain U288 S01960-05 exhibited enhanced growth in elevated NaCl concentrations.
非伤寒沙门氏菌（NTS）仍然是全球食源性疾病的主要原因。食品制造商通过结合多种方法来控制食品安全和质量，包括使用防腐剂（如有机酸、冷藏和加热）来实施障碍技术。我们评估了基因型多样化的沙门氏菌分离株在应激条件下的存活情况，以确定对亚最佳加工或烹饪具有潜在高风险的基因型。研究了亚致死热处理、干燥条件下的存活和在 NaCl 或有机酸存在下的生长情况。鸡沙门氏菌 287/91 菌株对所有应激条件最敏感。虽然没有一种菌株在 4°C 的食品基质中复制，但 S. Infantis 菌株 S1326/28 保持了最大的活力，六种菌株的活力显著降低。一种 S. Kedougou 菌株在食品基质中 60°C 的孵育中表现出比 S. Typhimurium U288、S Heidelberg、S. Kentucky、S. Schwarzengrund 和 S. Gallinarum 菌株更大的抗性。两种单相 S. Typhimurium 分离株 S04698-09 和 B54Col9 对干燥的耐受性最强，明显超过 S. Kentucky 和 S. Typhimurium U288 菌株。一般来说，12 mM 乙酸或 14 mM 柠檬酸的存在导致肉汤中生长减少的模式相似，但这在 S. Enteritidis 和 S. Typhimurium 菌株 ST4/74 和 U288 S01960-05 中没有观察到。尽管测试的浓度较低，但乙酸对生长的影响中等较大。在 6%NaCl 的存在下观察到类似的生长减少模式，但值得注意的是，S. Typhimurium 菌株 U288 S01960-05 在升高的 NaCl 浓度下表现出增强的生长。
