Short‐chain fatty acids affect cell‐association and invasion of HEp‐2 cells bySalmonella typhimurium

Abstract

This study demonstrates that the growth of S. typhimurium in Luria Bertani broth supplemented with acetate, propionate, butyrate, or a mixture of the three SCFA, affected cell-association and the ability to invade cultured HEp-2 cells. Cell-association and invasion was determined after growth for 4 h of growth in the presence of the SCFA at pH 6 and 7. The results suggest that the growth rate of the culture may have affected cell-association and invasion since accompanying the significant decrease in growth rate in the presence of SCFA at pH 6 was a decrease in cell-association and invasion. However, the results also suggest that the individual SCFA may play a role in modulating cell-association and the invasion phenotype and the regulation of cell-association and invasion by the SCFA was dependent on the concentration and the pH of the medium. Although the growth rates were similar for S. typhimurium in the SCFA mixture, butyrate (100 mM) and propionate (50 mM) at pH 6, differences in cell-association and invasion were observed among these cultures. Also, at pH 7, differences were observed among the SCFA treatments even though the growth rates were similar.

The use of organic acids to combatSalmonellain poultry: a mechanistic explanation of the efficacy

“…When S. Typhimurium was pre-incubated in growth media supplemented with various concentrations of butyrate and propionate, epithelial cell invasion was suppressed. However, if the cells were preincubated in media supplemented with acetate, invasion was still observed (Durant et al , 1999;Lawhon et al , 2002;Van Immerseel et al , 2004a). Similar results were obtained with S. Enteritidis when primary caecal epithelial cells of the chicken were employed (Van Immerseel et al , 2004a).…”

Medium-Chain Fatty Acids Decrease Colonization and Invasion through hilA Suppression Shortly after Infection of Chickens with Salmonella enterica Serovar Enteritidis

“…The regulation by organic acids of the invasion of Salmonella has already been reported for SCFA, with acetic acid leading to an increase in invasion while propionic and butyric acid decrease invasion 2-to 10-fold (8,15,23). MCFA seem to decrease invasion at least to the same extent as butyric acid but at lower concentrations.…”

Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

“…For S. Typhimurium incubated for 4 h in the presence of SCFA, acetate at pH 6.0 and 7.0 did not alter attachment, and only slight increases in invasion occurred, while propionate and butyrate dramatically decreased attachment and invasion at pH 6.0 but not at pH 7.0. There were also indications that these S. Typhimurium responses were growth dependent, particularly in the presence of propionate and butyrate at pH 6.0, which reduced the growth rate considerably (341). However, when late-logarithmic-phase (12 h) and stationary-phase (18 h) S. Typhimurium cells were compared (342,343), all SCFAs reduced cell attachment at pH 6.0 and 7.0 but only marginally influenced invasion for late-log-phase cultures of Salmonella.…”

“…Durant et al conducted a series of tissue culture studies with an epidermal carcinoma cell line (HEp-2) to determine the influence of S. Typhimurium after growth in either a mixture or separate intestinal concentrations of SCFA (acetate, propionate, and butyrate at pH 6.0 or 7.0) on its subsequent ability to adhere to and invade tissue culture cells (341)(342)(343). For S. Typhimurium incubated for 4 h in the presence of SCFA, acetate at pH 6.0 and 7.0 did not alter attachment, and only slight increases in invasion occurred, while propionate and butyrate dramatically decreased attachment and invasion at pH 6.0 but not at pH 7.0.…”