Enteritidis has brought great harm to public health, animal production and food safety worldwide. The biofilm formed by Enteritidis plays a critical role in microbial cross-contamination. Small non-coding RNAs (sRNAs) have been demonstrated to be responsible for regulating the formation of biofilm. The sRNA SaaS has been identified previously, that promotes pathogenicity by regulating invasion and virulence factors. However, whether the SaaS is implicated in regulating biofilm formation in abiotic surfaces remains unclear. This study aimed to clarify the effect of SaaS in Enteritidis and explore the modulatory mechanism on the biofilm formation. Motility characteristics and total biomass of biofilm of test strains were investigated by the phenotypes in three soft agar plates and crystal violet staining in polystyrene microplates. Studies of microscopic structure and extracellular polymeric substances (EPS) of biofilm on solid surfaces were carried out using confocal laser scanning microscope (CLSM) and Raman spectra. Transcriptomics and proteomics were applied to analyze the changes of gene expression and EPS component. The RNA-protein pull-down and promoter–reporter β-galactosidase activity assays were employed to analyze RNA binding proteins and identify target mRNAs, respectively. SaaS inhibits biofilm formation by repressing the adhesion potential and the secretion of EPS components. Integration of transcriptomics and proteomics analysis revealed that SaaS strengthened the expression of the flagellar synthesis system and downregulated the expression of curli amyloid fibers. Furthermore, RNA-protein pull-down interactome datasets indicated that SaaS binds to Hfq (an RNA molecular chaperone protein, known as a host factor for phage Qbeta RNA replication) uniquely among 193 candidate proteins, and promoter–reporter β-galactosidase activity assay confirmed target mRNAs including , and . SaaS inhibits the properties of bacterial mobility, perturbs the secretion of EPS, and contributes to the inhibition of biofilm formation by interacting with target mRNA (, and ) through the Hfq-mediated pathway.

中文翻译：

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一种靶向 hilD、cheA 和 csgA 的反式作用 sRNA SaaS，可抑制肠炎沙门氏菌生物膜形成


肠炎病给全球公共卫生、动物生产和食品安全带来了巨大危害。肠炎杆菌形成的生物膜在微生物交叉污染中起着至关重要的作用。小非编码 RNA (sRNA) 已被证明负责调节生物膜的形成。 sRNA SaaS 先前已被鉴定，它通过调节入侵和毒力因子来促进致病性。然而，SaaS 是否参与调节非生物表面生物膜的形成仍不清楚。本研究旨在阐明SaaS在肠炎中的作用并探讨其对生物膜形成的调节机制。通过三块软琼脂平板上的表型和聚苯乙烯微孔板中的结晶紫染色来研究测试菌株的运动特性和生物膜总生物量。使用共焦激光扫描显微镜（CLSM）和拉曼光谱对固体表面生物膜的微观结构和胞外聚合物（EPS）进行了研究。应用转录组学和蛋白质组学分析基因表达和EPS成分的变化。 RNA 蛋白下拉和启动子-报告基因 β-半乳糖苷酶活性测定分别用于分析 RNA 结合蛋白和鉴定靶 mRNA。 SaaS 通过抑制粘附电位和 EPS 成分的分泌来抑制生物膜形成。转录组学和蛋白质组学分析的整合表明，SaaS 增强了鞭毛合成系统的表达并下调了 Curli 淀粉样纤维的表达。 此外，RNA-蛋白质下拉相互作用组数据集表明，在 193 个候选蛋白质中，SaaS 与 Hfq（一种 RNA 分子伴侣蛋白，被称为噬菌体 Qbeta RNA 复制的宿主因子）独特地结合，并且启动子-报告基因 β-半乳糖苷酶活性测定证实目标 mRNA 包括 、 和 。 SaaS 抑制细菌移动性，干扰 EPS 的分泌，并通过 Hfq 介导的途径与靶 mRNA (、和) 相互作用，有助于抑制生物膜形成。