Gast R K, Porter R E, Hold P S
USDA-ARS, Southeast Poultry Research Laboratory, Athens, Georgia 30605, USA.
Avian Dis. 1997 Jan-Mar;41(1):195-202.
Detecting Salmonella enteritidis contamination in eggs has become the cornerstone of many programs for reducing egg-borne disease transmission, but egg culturing is time consuming and laborious. Preliminary screening tests are thus generally applied to minimize the number of flocks from which eggs must be cultured. The usefulness of such tests is directly proportional to both their detection sensitivity and their ability to predict the likelihood of egg contamination. In the present study, samples were collected for 24 days after groups of laying hens were orally inoculated with S. enteritidis. Eggs from each hen were cultured for S. enteritidis in the contents and samples of egg yolk were diluted and tested for specific antibodies to S. enteritidis flagella using both experimental and commercially available enzyme-linked immunosorbent assay (ELISA) methods. Samples of voided feces were also collected regularly from each bird and cultured for S. enteritidis. Although fecal shedding and egg yolk antibody production followed opposite patterns over time (fecal shedding was decreasing as egg yolk antibody titers were increasing), tests for both parameters were effective in predicting whether particular hens would lay contaminated eggs. Among hens that laid at least one egg contaminated by S. enteritidis, 82% were detected as infected by fecal culturing and 96% by the experimental egg yolk ELISA test. Using easily collected samples, egg yolk antibody testing offers a rapid and effective screening method for identifying S. enteritidis-infected laying flocks that might lay contaminated eggs.
检测鸡蛋中的肠炎沙门氏菌污染已成为许多减少蛋源性疾病传播项目的基石，但鸡蛋培养既耗时又费力。因此，通常会采用初步筛查测试，以尽量减少需要进行鸡蛋培养的鸡群数量。此类测试的有效性与它们的检测灵敏度以及预测鸡蛋污染可能性的能力直接相关。在本研究中，给产蛋鸡群口服接种肠炎沙门氏菌后，连续24天采集样本。对每只母鸡所产鸡蛋的内容物进行肠炎沙门氏菌培养，并将蛋黄样本稀释，然后使用实验性和市售的酶联免疫吸附测定（ELISA）方法检测针对肠炎沙门氏菌鞭毛的特异性抗体。还定期从每只鸡采集粪便样本，进行肠炎沙门氏菌培养。尽管随着时间推移，粪便排菌和蛋黄抗体产生呈现相反的模式（粪便排菌减少，而蛋黄抗体滴度增加），但这两个参数的检测都能有效地预测特定母鸡所产鸡蛋是否会被污染。在产下至少一枚被肠炎沙门氏菌污染鸡蛋的母鸡中，82%通过粪便培养检测出感染，96%通过实验性蛋黄ELISA检测出感染。利用易于采集的样本，蛋黄抗体检测为识别可能产下受污染鸡蛋且感染肠炎沙门氏菌的产蛋鸡群提供了一种快速有效的筛查方法。
