Efficacy of Salmonella enteritidis-immune lymphokines on horizontal transmission of S-arizonae in turkeys and S-gallinarum in chickens

Salmonella arizonae (SA) and S. gallinarum (SG) are of economic importance to international poultry production because of their pathogenesis in young poultry during the first week after hatching. Previous studies from our lab oratory have shown immune lymphokines (ILK) produced by S. enteritidis (SE) -immunized chickens provide protection against SE organ invasion in day-old chickens and turkey poults. Previous studies have also demonstrated that S G organ invasion was significantly decreased by administration of ILK to br oiler chicks. The objective of the present study was to determine the effec t of ILK on the incidence of horizontal transmission of SA in turkey poults and of SG in broiler chicks. The effect of ILK administration on horizonta l transmission of SA in poults and SG in chicks was assessed in a seeder/co ntact model. Seeders were challenged with the appropriate bacterium (SA tur keys, SG chicks), contacts were either untreated or administered ILK. Seede rs and contacts cohabited within an experimental group throughout the exper iment. Mortality and organ invasion as a result of horizontal transmission were determined. There were no significant differences in mortality between non-treated and ILK-treated contact poults. In contrast, SG was extremely pathogenic to young broiler chicks. Non-treated contact chicks had a mortal ity rate of approximately 68% whereas significant (P < 0.05) reduction in m ortality was demonstrated in the contact chicks treated with ILK (15%). Hor izontal transmission, as determined by organ invasion, of SA to contact tur key poults and SG to contact broiler chicks was also significantly (P < 0.0 5) decreased by immunoprophylactic administration of ILK. Bacterial recover y of SA from the liver/spleen and the cecal tonsil in contact poults and SC from contact chicks treated with ILK was dramatically reduced when compare d to non-treated contact poults and chicks. Our results strongly suggest th e immunoprophylactic administration of SE-immune lymphokines to young turke y poults and broiler chicks significantly reduces the horizontal transmissi on of Salmonella in poultry. These results suggest the possibilities of usi ng a non-vaccine immunologically-based preventative strategy against Salmon ella in poultry. (C) 1999 Elsevier Science B.V. All rights reserved.