Eliminating the carriage of Salmonella enterica serovar Enteritidis in domestic fowls by feeding activated charcoal from bark containing wood vinegar liquid (Nekka-Rich)

Abstract

The protective efficacy of activated charcoal containing wood vinegar liquid (Nekka-Rich) against intestinal infection with Salmonella enterica serovar Enteritidis was sought. In the present study, the adsorption effects of activated charcoal of Nekka-Rich on S. Enteritidis and normal bacterial flora in the intestine, Enterococcus faecium, were examined. S. Enteritidis was effectively adsorbed by activated charcoal of Nekka-Rich. On the other hand, activated charcoal of Nekka-Rich showed lower binding capacity to E.faecium. The effects of wood vinegar liquid included in Nekka-Rich on the growth of S. Enteritidis and normal bacterial flora in the intestine, E. faecium and Bifidobacterium thermophilum, were also assessed. Wood vinegar liquid had an inhibitory effect on the S. Enteritidis growth, whereas growth of E. faecium and B. thermophilum was enhanced by wood vinegar liquid. Furthermore, the protective effects of Nekka-Rich were evaluated in a challenge chicken model with S. Enteritidis. Chickens were fed a basal diet containing Nekka-Rich or immunized with commercially obtained S. Enteritidis vaccine and challenged with S. Enteritidis. Significantly less fecal excretion of S. Enteritidis was observed in chickens fed Nekka-Rich for 10 d after challenge. On d 15 after challenge, S. Enteritidis was not isolated from fecal samples. On the other hand, immunization of chickens with S. Enteritidis vaccine did not fully inhibit bacterial growth. Fecal excretion of S. Enteritidis was consistently observed in the vaccinated chickens after challenge. These results suggest that Nekka-Rich would be a good product for eliminating the carriage of S. Enteritidis in domestic fowl.