Spermidine constitutes a key determinant of motility and attachment of Salmonella Typhimurium through a novel regulatory mechanism

Nair, AV and Singh, A and Devasurmutt, Y and Rahman, SA and Tatu, US and Chakravortty, D (2024) Spermidine constitutes a key determinant of motility and attachment of Salmonella Typhimurium through a novel regulatory mechanism. In: Microbiological Research, 281 (281).

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Abstract

Spermidine is a poly-cationic molecule belonging to the family of polyamines and is ubiquitously present in all organisms. Salmonella synthesizes, and harbours specialized transporters to import spermidine. A group of polyamines have been shown to assist in Salmonella Typhimurium's virulence and regulation of Salmonella pathogenicity Inslad 1 (SPI-1) genes and stress resistance; however, the mechanism remains elusive. The virulence trait of Salmonella depends on its ability to employ multiple surface structures to attach and adhere to the surface of the target cells before invasion and colonization of the host niche. Our study discovers the mechanism by which spermidine assists in the early stages of Salmonella pathogenesis. For the first time, we report that Salmonella Typhimurium regulates spermidine transport and biosynthesis processes in a mutually inclusive manner. Using a mouse model, we show that spermidine is critical for invasion into the murine Peyer's patches, which further validated our in vitro cell line observation. We show that spermidine controls the mRNA expression of fimbrial (fimA) and non-fimbrial adhesins (siiE, pagN) in Salmonella and thereby assists in attachment to host cell surfaces. Spermidine also regulated the motility through the expression of flagellin genes by enhancing the translation of sigma-28, which features an unusual start codon and a poor Shine-Dalgarno sequence. Besides regulating the formation of the adhesive structures, spermidine tunes the expression of the two-component system BarA/SirA to regulate SPI-1 encoded genes. Thus, our study unravels a novel regulatory mechanism by which spermidine exerts critical functions during Salmonella Typhimurium pathogenesis. © 2024 Elsevier GmbH

Item Type:	Journal Article
Publication:	Microbiological Research
Publisher:	Elsevier GmbH
Additional Information:	The copyright for this article belongs to Publisher
Keywords:	Adhesives; Amines; Biochemistry; Cell culture; Cell membranes; Genes; Plants (botany), Adhesin; Flagellum; Intestinal epithelial cells; Polyamines; Regulatory mechanism; Salmonella pathogenicity islands; Salmonella typhimurium; Sigma factor; Sigma-factor28 salmonella- pathogenicity island-1; Spermidine, Salmonella, cell organelle; colonization; gene expression; motility; pathogenicity; RNA; virulence
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	01 Mar 2024 06:22
Last Modified:	01 Mar 2024 06:22
URI:	https://eprints.iisc.ac.in/id/eprint/83878

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