柔嫩艾美耳球虫感染对蛋鸡生产肠炎沙门氏菌污染蛋和感染肠炎沙门氏菌敏感性的影响

Enhancing Effect of Eimeria tenella Infection on the Production of Salmonella enteritidis contaminated Eggs and Susceptibility of Laying Hens to S. enteritidis Infection

为揭示球虫感染对蛋鸡的肠炎沙门氏菌敏感性及鸡蛋的肠炎沙门氏菌污染率的影响而进行了本研究。结果显示，柔嫩艾美耳球虫感染对蛋鸡生产肠炎沙门氏菌污染蛋及感染肠炎沙门氏菌的敏感性均具有增强作用。具体表现为：柔嫩艾美耳球虫感染可使肠炎沙门氏菌污染蛋壳显著增多（Ｐ＜０．０５）；球虫感染鸡所产蛋，无论是新鲜的还是贮存１周后的，其蛋内容物的肠炎沙门氏菌阳性率比仅感染肠炎沙门氏菌鸡所产蛋要高；球虫感染鸡盲肠中的沙门氏菌阳性率和沙门氏菌数显著增加（Ｐ＜０．０１）；球虫感染鸡输卵管中的肠炎沙门氏菌也有增多；球虫感染使泄殖腔拭子的肠炎沙门氏菌阳性率增加。研究结果表明，柔嫩艾美耳球虫感染可以增加鸡群中肠炎沙门氏菌的水平及其垂直传播的危险。

Experiments were conducted to determine the effect of Eimeria tenella infection on the production of Salmonella enteritidis contaminated eggs and susceptibility of egg laying hens to S.enteritidis infection. The dose of sporulated oocysts of E.tenella used in the present study was 2×10 5 per chicken. When hens were infected with 10 6 colony forming units (CFU) of S.enteritidis, E.tenella infection resulted in a significant increase (P<0.05) of S. enteritidis contamination on the shells of fresh eggs, but not in the egg contents of fresh eggs and stored eggs. Significant effects of coccidial infection on the contamination of eggs(shells and contents) were not observed when hens were infected with 10 4 CFU of S.enteritidis. Surface disinfected eggs pooled within each week from individual chickens infected with 10 8 CFU of S.enteritidis and E.tenella showed significantly (P< 0.05 ) more S.enteritidis contamination on eggshells, but not in egg contents, than those from hens infected with S. enteritidis alone. Coccidial infection resulted in a significant increase of S.enteritidis in the cloacal swabs of hens infected with 10 8 CFU S.enteritidis. In all the experiments, chickens infected with S. enteritidis and E.tenella showed significantly higher positive rates and counts of cecal S. enteritidis than those infected with S. enteritidis alone. No significant differences of S.enteritidis positive rates in ovary, oviduct, liver, and spleen were noted whether the hens were infected with a combination of E.tenella and S.enteritidis or with S.enteritidis alone. The results suggested that the infection of E.tenella may enhance the production of Salmonella enteritidis contaminated eggs and the susceptibility of laying hens to S enteritidis infection.