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Short-chain volatile fatty acids modulate the expression of the hilA and invF genes of Salmonella typhimurium.
J Food Prot. 2000 May; 63(5):573-8.JF

Abstract

The ability of Salmonella typhimurium to invade the intestinal mucosal cells is an important step in pathogenesis. This invasion process requires genes encoded on the Salmonella pathogenicity island 1 (SPI1). Two transcriptional activators, HilA and InvF, encoded in SPII regulate the expression of invasion genes in response to environmental stimuli such as osmolarity, oxygen tension, and pH. During its pathogenic life cycle, Salmonella typhimurium is also exposed to short-chain fatty acids (SCFA), especially acetate, propionate, and butyrate, in the intestinal lumen, as well as the SCFA used as food preservatives. The effects of SCFA on the expression of hilA and invF-lacZY transcriptional fusions were examined to determine the potential role of SCFA in the pathogenesis of Salmonella typhimurium. Growth rates were reduced by increasing SCFA concentrations at pH 6 but not at pH 7. At pH 7, hilA and invF expression was induced by acetate but not by propionate or butyrate, while at pH 6, all SCFA induced hilA and invF expression at 1 h. In general, hilA and invF expression levels when compared to respective control responses were higher at 1 h than at 4 and 8 h in the presence of most SCFA concentrations at pH 6. However, expression levels at 4 and 8 h were either similar or higher than the 1-h responses for the hilA-lacZY fusion strain in the presence of acetate while exposure to 20 mM propionate yielded similar levels of expression at 1, 4, and 8 h. The pH-dependent manner of induction suggests that entry of SCFA into the cell was necessary for induction. We speculate that SCFA may serve as an environmental signal that triggers the expression of invasion genes in the gastrointestinal tract.

Authors+Show Affiliations

Department of Poultry Science, Texas A&M University, College Station 77843-2472, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

10826713

Citation

Durant, J A., et al. "Short-chain Volatile Fatty Acids Modulate the Expression of the hilA and invF Genes of Salmonella Typhimurium." Journal of Food Protection, vol. 63, no. 5, 2000, pp. 573-8.
Durant JA, Corrier DE, Ricke SC. Short-chain volatile fatty acids modulate the expression of the hilA and invF genes of Salmonella typhimurium. J Food Prot. 2000;63(5):573-8.
Durant, J. A., Corrier, D. E., & Ricke, S. C. (2000). Short-chain volatile fatty acids modulate the expression of the hilA and invF genes of Salmonella typhimurium. Journal of Food Protection, 63(5), 573-8.
Durant JA, Corrier DE, Ricke SC. Short-chain Volatile Fatty Acids Modulate the Expression of the hilA and invF Genes of Salmonella Typhimurium. J Food Prot. 2000;63(5):573-8. PubMed PMID: 10826713.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Short-chain volatile fatty acids modulate the expression of the hilA and invF genes of Salmonella typhimurium. AU - Durant,J A, AU - Corrier,D E, AU - Ricke,S C, PY - 2000/5/29/pubmed PY - 2000/8/6/medline PY - 2000/5/29/entrez SP - 573 EP - 8 JF - Journal of food protection JO - J Food Prot VL - 63 IS - 5 N2 - The ability of Salmonella typhimurium to invade the intestinal mucosal cells is an important step in pathogenesis. This invasion process requires genes encoded on the Salmonella pathogenicity island 1 (SPI1). Two transcriptional activators, HilA and InvF, encoded in SPII regulate the expression of invasion genes in response to environmental stimuli such as osmolarity, oxygen tension, and pH. During its pathogenic life cycle, Salmonella typhimurium is also exposed to short-chain fatty acids (SCFA), especially acetate, propionate, and butyrate, in the intestinal lumen, as well as the SCFA used as food preservatives. The effects of SCFA on the expression of hilA and invF-lacZY transcriptional fusions were examined to determine the potential role of SCFA in the pathogenesis of Salmonella typhimurium. Growth rates were reduced by increasing SCFA concentrations at pH 6 but not at pH 7. At pH 7, hilA and invF expression was induced by acetate but not by propionate or butyrate, while at pH 6, all SCFA induced hilA and invF expression at 1 h. In general, hilA and invF expression levels when compared to respective control responses were higher at 1 h than at 4 and 8 h in the presence of most SCFA concentrations at pH 6. However, expression levels at 4 and 8 h were either similar or higher than the 1-h responses for the hilA-lacZY fusion strain in the presence of acetate while exposure to 20 mM propionate yielded similar levels of expression at 1, 4, and 8 h. The pH-dependent manner of induction suggests that entry of SCFA into the cell was necessary for induction. We speculate that SCFA may serve as an environmental signal that triggers the expression of invasion genes in the gastrointestinal tract. SN - 0362-028X UR - https://www.unboundmedicine.com/medline/citation/10826713/Short_chain_volatile_fatty_acids_modulate_the_expression_of_the_hilA_and_invF_genes_of_Salmonella_typhimurium_ DB - PRIME DP - Unbound Medicine ER -