The Use of Tannins to Control Salmonella Typhimurium Infections in Pigs

P>The aim of this study was to determine whether a hydrolysable tannin extract of sweet chestnut wood (Globatan (R)) has an inhibitory effect on Salmonella Typhimurium survival both in vitro and in vivo in pigs. In a first experiment, the minimal inhibitory concentration of Globatan (R) on 57 Salmonella Typhimurium isolates was determined. For all isolates, an MIC of 160-320 mu g/ml was found. The second in vitro study revealed that Salmonella growth was strongly reduced using Globatan (R) concentrations of 25-50 mu g/ml and nearly completely inhibited at a concentration of 100 mu g/ml Globatan (R). In an in vivo trial, two groups of six piglets, each group receiving feed with or without the addition of Globatan (R) (3 g/kg), were orally inoculated with 107 colony forming units of a Salmonella Typhimurium strain. Globatan (R) had no effect on faecal excretion of Salmonella, and no differences in colonization of the intestines and internal organs were demonstrated in pigs euthanized at 4 days post-inoculation. In conclusion, the hydrolysable tannin extract used in this study showed strong action against Salmonella Typhimurium in vitro but not in vivo.