Chickens were treated prophylactically with the soluble products from
Con A-stimulated T-lymphocytes from Salmonella enteritidis-infected ch
ickens in order to investigate the effect of such prophylactic treatme
nt on organ invasion by S. enteritidis. At 18 days of age, chicks were
injected intraperitoneally with one of the following: A) the Amicon Y
M 10 ultrafiltrate from immunized chickens, B) the Amicon YM 10 ultrar
etentate material from immunized chickens, or C) the Amicon YM 10 ultr
aretentate material from control nonimmune chickens. Thirty minutes af
ter lymphokine injection, all birds were challenged per os with 10(8)
colony-forming units of S. enteritidis. At both 1 and 6 days post-chal
lenge, prophylactic treatment of chickens with the immune retentate re
sulted in a 51-60% reduction in S. enteritidis organ invasion. The red
uction in S. enteritidis organ invasion was associated with a signific
ant increase in lamina propria thickness based on morphometric analysi
s (P < 0.05). These results demonstrate that the prophylactic administ
ration of S. enteritidis-immune lymphokines induces protection against
S. enteritidis organ invasion, which is associated with a measurable
microanatomical change in the cecal mucosa.