U. S. National Poultry Research Center, USDA Agricultural Research Service, Athens, GA 30605.
Department of Poultry Science, North Carolina State University, Raleigh, NC 29765.
Poult Sci. 2019 Oct 1;98(10):5023-5027. doi: 10.3382/ps/pez222.
Human illness caused by the consumption of eggs contaminated with Salmonella Enteritidis is a continuing international public health concern. This pathogen is deposited inside the edible contents of eggs as a consequence of its ability to colonize reproductive tissues in infected hens. Conditions in the housing environment can influence the persistence and transmission of avian Salmonella infections, but the food safety ramifications of different poultry management systems are not entirely clear. The present study assessed the deposition of S. Enteritidis inside eggs laid by groups of experimentally infected laying hens of 4 commercial genetic lines (designated as white egg lines W1 and W2 and brown egg lines B1 and B2). Groups of hens from each line were housed at 555 cm2 of floor space per bird in both conventional cages and colony units enriched with access to perches and nesting areas. All hens were orally inoculated with 5.75 × 107 cfu of a 2-strain S. Enteritidis mixture, and the internal contents of eggs laid 5 to 24 D post-inoculation were cultured to detect the pathogen. No significant differences in egg contamination frequencies were found between the 2 housing systems for any of the hen lines. Contaminated eggs were laid between 7 and 21 D post-inoculation at an overall frequency of 2.47%, ranging from 0.25 to 4.38% for the 4 hen lines. The frequency of S. Enteritidis recovery from egg samples was significantly (P < 0.05) lower for line B2 than for any of the other lines, and the egg contamination frequency for line W1 was significantly greater than for line W2. The overall incidence of contamination among white eggs (3.38%) was significantly higher than among brown eggs (1.56%). These results demonstrate that S. Enteritidis deposition inside eggs can vary between genetic lines of infected laying hens, but housing these hens in 2 different systems did not affect the production of contaminated eggs.
人因食用受肠炎沙门氏菌污染的鸡蛋而患病，这是一个持续存在的国际公共卫生问题。这种病原体能够在感染母鸡的生殖组织中定植，因此会沉积在鸡蛋的可食用部分内。鸡舍环境条件会影响禽源沙门氏菌感染的持续和传播，但不同家禽管理系统的食品安全影响尚不完全清楚。本研究评估了肠炎沙门氏菌在 4 个商业遗传品系（分别为白色蛋品系 W1 和 W2 以及棕色蛋品系 B1 和 B2）的实验感染产蛋母鸡所产鸡蛋中的沉积情况。每个品系的母鸡组都以每只 555 平方厘米的鸡舍空间饲养，分别饲养在普通笼和富含栖木和巢区的群体单元中。所有母鸡都经口接种了 5.75×107cfu 的两菌株肠炎沙门氏菌混合物，接种后 5 至 24 天所产鸡蛋的内部内容物被培养以检测病原体。在任何一种母鸡品系中，两种鸡舍系统之间的鸡蛋污染频率均无显著差异。污染鸡蛋在接种后 7 至 21 天内产下，总频率为 2.47%，4 个母鸡品系的范围为 0.25%至 4.38%。肠炎沙门氏菌从鸡蛋样本中的回收率显著（P<0.05）低于品系 B2，而品系 W1 的鸡蛋污染频率显著高于品系 W2。白色蛋（3.38%）的总体污染发生率显著高于棕色蛋（1.56%）。这些结果表明，肠炎沙门氏菌在感染产蛋母鸡的不同遗传品系之间沉积情况不同，但将这些母鸡饲养在两种不同系统中并不会影响污染鸡蛋的生产。
