Transcriptome analysis revealed the role of capsular polysaccharides in desiccation tolerance of foodborne Staphylococcus aureus
Transcriptome analysis revealed the role of capsular polysaccharides in desiccation tolerance of foodborne Staphylococcus aureus
复制标题
转录组分析揭示了荚膜多糖在食源性金黄色葡萄球菌的干燥耐受性中的作用。
DOI：
10.1016/j.foodres.2022.111602
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发表时间：
2022-07-02
影响因子：
8.1
通讯作者：
Xue，Ting
中科院分区：
文献类型：
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作者：
Wang，Hui;Shen，Jiawei;Xue，Ting
金黄色葡萄球菌(S.金黄色葡萄球菌）是影响食品安全的重要因素。它可以在长期的干燥压力下存活，并污染具有中等至低水分活度的食品。然而，它在低水分活度胁迫下存活和持续存在的特定分子机制往往被忽视。本研究采用转录组分析的方法，研究了干旱胁迫对S.金黄色RMSA24，一种食源性从原料奶样品中分离的金黄色葡萄球菌菌株。转录组分析结果显示，脱水处理后，荚膜多糖（CPs）合成相关基因的mRNA水平显著上调，这一点得到了实时荧光定量PCR的进一步证实。菌落计数实验结果表明，与野生型菌株相比，突变株的存活率有所降低。生物膜形成实验显示，CPs突变体的生物膜形成能力与野生型无明显差异。这些结果表明，CPs突变体通过非生物膜依赖性途径降低了金黄色葡萄球菌RMSA24的脱水抗性。本研究为食品中抗干燥的机制提供了新的证据。并且有助于防止由这种细菌引起的食品污染。
Staphylococcus aureus(S. aureus) is a momentous factor affecting food safety. It can survive under long-term desiccation stress and contaminate foods that have intermediate to low water activities. However, the specific molecular mechanisms by which it survives and persists under low water activity stress are often overlooked. In this study, transcriptome analysis was applied to investigate the effect of desiccation stress on gene expression ofS. aureusRMSA24, a food-borneS. aureusstrain that was isolated from a raw milk sample. Results of transcriptome analysis showed that the mRNA levels of genes related to capsular polysaccharides (CPs) synthesis were significantly upregulated after desiccation treatment, which was further confirmed by real-time reverse transcription PCR assays. Furthermore, the results of colony count experiments demonstrated that the survival of CPs mutant was decreased compared with the wild type strain. And the biofilm formation ability of CPs mutant showed no difference compared with that of wild type according to biofilm formation assays. Those results indicated that CPs mutant decrease the resistance to desiccation inS. aureusRMSA24 via a biofilm-independent pathway. This study provides new evidence regarding the mechanisms of desiccation resistance of food-borneS. aureusand contributes to the prevention of food contamination caused by this bacterium.