Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/1997
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Neonatal poultry are most susceptible to Salmonella infections during the first 4 days post-hatch, after which they become increasingly more resistant to infection. It is during this first 4 days post-hatch that innate defense mechanisms must function to control Salmonella from multiplying to numbers capable of overwhelming any response that is generated. Since traditional vaccination of poultry against Salmonella has met with limited success and commercial acceptance, appropriate manipulation of the avian immune system may contribute to the solution of salmonellosis problems in commercial poultry. Our laboratory has demonstrated that T lymphocytes derived from Salmonella enteritidis-immune chickens produce lymphokines (ILK) that can convey a heterophilic-specific inflammatory response in neonatal chickens that significantly increases the innate resistance of these birds against organ infectivity by various serovars of paratyphoid and typhoid salmonella, which is in contrast to most Salmonella vaccines. Furthermore, this protective response is generated within 24 hours of the administration of ILK. Moreover, these lymphokines can be administered in ovo, orally, or as an aerosol with the protection persisting for at least six days with no evidence of any detrimental host pathology induced by the inflammatory reactions. These findings further suggest that the mechanism of host resistance to Salmonella in poultry may be less dependent on an antigen-specific response, but more contingent on initiating the correct innate responses early during an infection.