Medium-chain fatty acids decrease colonization and invasion through hilA suppression shortly after infection of chickens with Salmonella enterica serovar Enteritidis

Appl Environ Microbiol. 2004 Jun;70(6):3582-7. doi: 10.1128/AEM.70.6.3582-3587.2004.


The most common source of Salmonella infections in humans is food of poultry origin. Salmonella enterica serovar Enteritidis has a particular affinity for the contamination of the egg supply. In this study, the medium-chain fatty acids (MCFA), caproic, caprylic, and capric acid, were evaluated for the control of Salmonella serovar Enteritidis in chickens. All MCFA were growth inhibiting at low concentrations in vitro, with caproic acid being the most potent. Contact of Salmonella serovar Enteritidis with low concentrations of MCFA decreased invasion in the intestinal epithelial cell line T84. By using transcriptional fusions between the promoter of the regulatory gene of the Salmonella pathogenicity island I, hilA, and luxCDABE genes, it was shown that all MCFA decreased the expression of hilA, a key regulator related to the invasive capacity of Salmonella. The addition of caproic acid (3 g/kg of feed) to the feed of chicks led to a significant decrease in the level of colonization of ceca and internal organs by Salmonella serovar Enteritidis at 3 days after infection of 5-day-old chicks. These results suggest that MCFA have a synergistic ability to suppress the expression of the genes required for invasion and to reduce the numbers of bacteria in vivo. Thus, MCFA are potentially useful products for reducing the level of colonization of chicks and could ultimately aid in the reduction of the number of contaminated eggs in the food supply.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / drug effects
  • Bacterial Proteins / metabolism
  • Caproates / pharmacology
  • Caprylates / pharmacology
  • Cell Line, Tumor
  • Chickens / microbiology*
  • Colony Count, Microbial
  • Decanoic Acids / pharmacology
  • Fatty Acids / pharmacology*
  • Humans
  • Poultry Diseases / microbiology
  • Poultry Diseases / prevention & control
  • Salmonella Infections, Animal / microbiology
  • Salmonella Infections, Animal / prevention & control
  • Salmonella enteritidis / drug effects
  • Salmonella enteritidis / growth & development*
  • Salmonella enteritidis / pathogenicity*
  • Trans-Activators / drug effects*
  • Trans-Activators / metabolism


  • Bacterial Proteins
  • Caproates
  • Caprylates
  • Decanoic Acids
  • Fatty Acids
  • HilA protein, Salmonella
  • Trans-Activators
  • decanoic acid
  • octanoic acid