Introduction. Salmonella Typhimurium (STM) is a food-borne Gram-negative bacterium, which can infect humans and a wide range of livestock and poultry, causing a variety of diseases such as septicaemia, enteritis and abortion. Hypothesis/Gap Statement. We will decipher the impacts of sRNA STnc1280 on STM virulence and provide a theoretical basis to reveal the regulatory role and molecular mechanism of STnc1280. Aim. The main objective of this study was to clarify whether sRNA STnc1280 exerts regulatory roles on STM pathogenicity. Methodology. The STnc1280 gene was amplified and its molecular characteristics were analysed in this study. Then, STnc1280 gene deletion strain (STM-ΔSTnc1280) and the complementary strain (ΔSTnc1280/STnc1280) were constructed by λ-Red homologous recombination method, respectively, to analyse of adhesion and invasive ability and pathogenicity of different strains. Subsequently, the potential target gene regulated by STnc1280 was predicted using target RNA2 software, followed by the verification of the interaction between STnc1280 and target mRNA using the dual plasmid reporter system (DPRS). Furthermore, the mRNA and protein level of target gene was determined using qRT-PCR and Western blot, respectively. Results. The results revealed that the cell adhesion and invasive ability and pathogenicity of STM-ΔSTnc1280 were significantly reduced compared to STM-SL1344 strain, indicating that the deficiency of STnc1280 gene significantly influenced STM pathogenicity. The DPRS results showed that STnc1280 can interact with the mRNA of target gene gldA, thus suppressing the expression of lacZ gene. Furthermore, the level of gldA mRNA was not influenced in STM-ΔSTnc1280, but the expression of GldA protein decreased significantly. Conclusion. Combining the bioinformatic analysis, these findings suggested that STnc1280 may bind to the SD sequence of gldA mRNA, hindering the binding of ribosomes to gldA mRNA, thereby inhibiting the expression of GldA protein to modulate the virulence of STM.

中文翻译：

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STnc1280 是一种转码 sRNA，通过靶向鼠伤寒沙门氏菌中的 gldA mRNA 参与毒力调节

介绍。 鼠伤寒沙门氏菌（STM）是一种食源性革兰氏阴性细菌，可感染人类和多种畜禽，引起败血症、肠炎和流产等多种疾病。假设/差距陈述。我们将破译sRNA STnc1280对STM毒力的影响，为揭示STnc1280的调控作用和分子机制提供理论基础。目的。本研究的主要目的是阐明sRNA STnc1280是否对STM致病性发挥调节作用。方法。本研究扩增了STnc1280基因并分析了其分子特征。然后，通过λ-Red同源重组方法分别构建STnc1280基因缺失菌株（STM - ΔSTnc1280）和互补菌株（ΔSTnc1280/STnc1280），分析不同菌株的粘附侵袭能力和致病性。随后，利用target RNA2软件预测STnc1280调控的潜在靶基因，并利用双质粒报告系统（DPRS）验证STnc1280与靶mRNA之间的相互作用。此外，分别使用qRT-PCR和Western blot测定靶基因的mRNA和蛋白水平。结果。结果显示，与STM-SL1344菌株相比，STM - ΔSTnc1280的细胞粘附和侵袭能力以及致病性显着降低，表明STnc1280基因的缺陷显着影响了STM的致病性。 DPRS结果显示STnc1280可以与靶基因gldA的mRNA相互作用，从而抑制lacZ基因的表达。此外，STM- ΔSTnc1280中gldA mRNA的水平没有受到影响，但GldA蛋白的表达显着降低。结论。结合生物信息学分析，这些发现提示STnc1280可能与gldA mRNA的SD序列结合，阻碍核糖体与gldA mRNA的结合，从而抑制GldA蛋白的表达，从而调节STM的毒力。