Establishment and persistence of Salmonella typhimurium infection stimulated by Eimeria tenella in chickens

Abstract

The effect of the concurrent infections of Salmonella typhimurium and Eimeria tenella on the establishment and persistence of salmonella infection were studied in chickens using salmonella isolated from a broiler chicken. Two experiments, with three replications each, were conducted. In experiment 1, groups were composed of uninfected controls, birds infected with 40,000 E tenella oocysts, birds infected with a daily dose of 1 x 10(4) to 4 x 10(4) S typhimurium for five days after having been infected with coccidial oocysts, and birds infected with S typhimurium alone but following the same pattern as the previous group. Chickens were killed seven, 10 and 14 days after coccidial infection. In experiment 2, groups were composed of birds infected with S typhimurium and those infected with E tenella and S typhimurium in the same manner as experiment 1 but killed 17, 21, 24 and 28 days after coccidial infection. In both experiments, the number of salmonella in caecal contents and the number of chickens with salmonella in the caeca and in the liver were significantly greater in the concurrent infections than in the salmonella infection alone. No salmonella was recovered from the bile samples. Serum agglutinin was detected only from chickens infected with E tenella and S typhimurium. The results demonstrated that the establishment and persistence of S typhimurium infection were enhanced by E tenella infection in chickens.