EIMERIA-TENELLA INFECTION INDUCES RECRUDESCENCE OF PREVIOUS SALMONELLA-ENTERITIDIS INFECTION IN CHICKENS

Four experiments were conducted to examine the effect of Eimeria tenel la infection on the recrudescence of Salmonella enteritidis in previou sly infected chickens. Significant recrudescence of cecal colonization in the birds challenged with E. tenella was observed at 3 wk after S. enteritidis infection in Experiment 1, at 3 and 4 wk in Experiment 2, and at 3, 4, and 5 wk in Experiments 3 and 4. The recrudescence was i ndicated by .81 to 6.31 logs increase in cecal S. enteritidis counts a nd by higher percentages of ceca that were culture-positive. The possi ble prolonged cecal S, enteritidis shedding from chickens infected wit h coccidia into the environment might be important for the perpetuatio n of S. enteritidis infectious cycle. Except for Experiment 1, in whic h a significant higher culture-positive rate of the liver was detected in the coccidia-infected group, no significant difference of culture- positive rate of liver and spleen between the treatments was observed. The recrudescence of previous S. enteritidis infection caused by E. t enella infection was obviously related to the initial S. enteritidis d ose size and time of exposure to coccidia.