Medium-chain fatty acids may be effective at controlling Salmonella bacteria in chickens say researchers from Belgium and the Czech Republic. Their findings appear in the June 2004 issue of the journal Applied and Environmental Microbiology.

The leading cause of food-borne infections in humans, Salmonella bacteria is most commonly associated with poultry. Currently, short-chain fatty acids are being used to treat chickens and prevent infection. Although they have proven somewhat effective researchers believe that the use of medium-chain fatty acids (MCFA) may further decrease the number of acquired food-borne infections in humans.

In the study, MCFA's, caproic, caprylic, and capric acid (harmless fatty acids often found in vegetable oils and flavoring) were used to challenge the growth of Salmonella enterica serovar Enteritidis in the intestinal tract of chickens. Results showed that all MCFA inhibited growth with caproic acid causing the most resistance. More specifically, MCFA was able to decrease gene expression of hilA, a regulator of the invasive capability of Salmonella bacteria. Also, when used as a feed supplement, caproic acid substantially decreased levels of S. enterica serovar Enteritidis in 5 day-old chicks 3 days after infection.

"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," say the researchers. "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."

(F.V. Immerseel, J. De Buck, F. Boyen, L. Bohez, F. Pasmans, J. Volf, M. Sevcik, I. Rychlik, F. Haesebrouck, R. Ducatelle. 2004. Medium-chain fatty acids decrease colonization and invasion through hilA suppression
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Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
23-Jun-2004