Location: Food and Feed Safety Research
Title: Loxoribine pretreatment reduces Salmonella enteritidis organ invasion in 1-day-old chickens Authors
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 7, 2012
Publication Date: April 1, 2012
Citation: Swaggerty, C.L., He, L.H., Genovese, K.J., Duke, S.E., Kogut, M.H. 2012. Loxoribine pretreatment reduces Salmonella enteritidis organ invasion in 1-day-old chickens. Poultry Science. 91:1038-1042. Interpretive Summary: Baby chicks are very susceptible to bacterial infections (for example, Salmonella) the first week of life, and that leads to significant economic losses for the poultry industry. Therefore, ways to boost the chicks’ immune response against bacteria is becoming a very important area of research for all food animal producers, including the poultry industry. The purpose of this research was to determine if pre-treatment of baby chicks with an immune-boosting substance (Loxoribine) protected the chicks from being infected with Salmonella. Loxoribine was injected into the belly of baby chicks, and 4 hours later the chicks were given an oral challenge of Salmonella. The next day, the chicks were euthanized and the liver and spleen removed and cultured to see if we could isolate Salmonella. Pre-treatment of chicks with Loxoribine significantly reduced the amount of Salmonella we recovered. In summary, the results from this study showed baby chicks pre-treated with the immune-boosting substance, Loxoribine, were protected against organ invasion by Salmonella. The results obtained in this study indicate there is a potential application for using Loxoribine to increase protection of baby chicks when they are most susceptible to infections with Salmonella.
Technical Abstract: Young poultry exhibit a transient susceptibility to some infectious diseases, including Salmonella, during the first week of life that stems from immature innate and acquired defense mechanisms. Consequently, stimulation or modulation of the hosts’ natural immune response is emerging as an important area of interest for food animal producers, including the poultry industry. Toll-like receptor (TLR) agonists, including flagellin and CpG oligodeoxynucleotides (CpG-ODN), have been shown to boost the innate immune response in young chickens and increase their resistance against Salmonella enteritidis challenges. The objective of the present study was to determine if pre-treatment of day-old chicks with Loxoribine, a TLR7 agonist and immune modulator, protects young chicks from S. enteritidis organ invasion. Loxoribine (0-100 'g) was administered intra-abdominally (IA) to day-old broiler chicks, and 4 h later, the birds were challenged orally with S. enteritidis. At 24 h post-challenge, birds were euthanized and the liver and spleen aseptically removed and cultured for the presence of S. enteritidis. This was carried out on 3 separate occasions using 26-50 chicks per dose per experiment. Pre-treatment of chicks with Loxoribine (6.25-25 'g) significantly reduced (P'0.05) liver and spleen organ invasion by S. enteritidis. Higher doses (50-100 'g) of Loxoribine had no effect or rendered the birds more susceptible to organ invasion by S. enteritidis. In summary, the results from this study showed broiler chicks pre-treated with Loxoribine, a potent TLR7 agonist and immunomodulator, were protected against organ invasion by S. enteritidis. The results obtained in this study indicate there is a potential application for using Loxoribine to increase protection of young chicks when they are most susceptible to infections with Salmonella and that additional administration routes, doses, and timing should be evaluated.