Polyamines are small cationic amines required for modulating multiple cell process, including cell growth and DNA and RNA stability. In Salmonella polyamines are primarily synthesized from L-arginine or L-ornithine. Based on a previous study, which demonstrated that polyamines affect the expression of virulence gene in S. Typhimurium, we investigated the role of polyamines in the global gene and protein expression in S. Typhimurium. The depletion of polyamine biosynthesis led to down-regulation of genes encoding structural components of the Type Three Secretion system 1 (TTSS1) and its secreted effectors. Interestingly, Expression of HilA, which is the master regulator of Salmonella Pathogenicity Island 1 (SPI1), was only reduced at the post-transcriptional in the polyamine mutant. Enzymes related to biosynthesis and/or transport of several amino acids were up-regulated, just as the Mg²⁺-transport systems were three to six-fold up-regulated at both the transcriptional and protein levels. Furthermore, in the polyamine depletion mutant, proteins related to stress response (IbpA, Dps, SodB), were 2–5 fold up-regulated. Together our data provide strong evidence that polyamine depletion affects expression of proteins linked with virulence and stress response of S. Typhimurium. Furthermore, polyamines positively affected translation of HilA, the major regulator of SPI1.

多胺是调节多种细胞过程（包括细胞生长以及DNA和RNA稳定性）所需的小型阳离子胺。在沙门氏菌中，多胺主要由L-精氨酸或L-鸟氨酸合成。根据先前的研究，该研究表明多胺会影响S.毒力基因的表达。鼠伤寒，我们调查了多胺在S的整体基因和蛋白质表达中的作用。鼠伤寒 多胺生物合成的耗竭导致编码三型分泌系统1（TTSS1）及其分泌的效应子的结构成分的基因的下调。有趣的是，作为沙门氏菌致病岛1（SPI1）的主要调控因子的HilA的表达仅在多胺突变体的转录后降低。就像Mg ²⁺一样，与生物合成和/或几种氨基酸转运相关的酶也被上调。-转运系统在转录和蛋白质水平上被上调三至六倍。此外，在多胺耗竭突变体中，与应激反应有关的蛋白质（IbpA，Dps，SodB）被上调2至5倍。我们的数据一起提供了有力的证据，证明多胺耗竭会影响与S的毒力和应激反应有关的蛋白质表达。鼠伤寒 此外，多胺还积极影响SPI1的主要调控因子HilA的翻译。