Holt P S
U.S. Department of Agriculture, Southeast Poultry Research Laboratory, Athens, Georgia 30605, USA.
Avian Dis. 1995 Apr-Jun;39(2):239-49.
The impact of induced molting on the horizontal transmission of S. enteritidis was studied. In Expt. 1, every other hen in rows of either molted or unmolted hens was infected with S. enteritidis (1 x 10(6) bacteria/hen). S. enteritidis was transmitted more rapidly to the unchallenged hens in the adjacent cages of molted hens than in unmolted hens, and these molted hens shed significantly more of the organism than unmolted hens. In Expts. 2 and 3, the center hen in two rows each of 11 molted and unmolted hens was infected with S. enteritidis (dose of 6-8 x 10(4) in Expt. 2 and 1 x 10(3) in Expt. 3). In both trials of Expt. 2, the rate of transmission was significantly higher in molted hens than in unmolted hens, and the molted hens shed significantly more of the organism. In Trial 1 of Expt. 3, molting had little effect on S. enteritidis shedding. In Trial 2 of Expt. 3, however, molted hens had significantly higher shed rates and shed more S. enteritidis than the unmolted hens. Individual hens in Expts. 2 and 3 frequently shed more S. enteritidis than the original challenge. The amplification of intestinal S. enteritidis in the molted hens plus their previously described higher susceptibility to S. enteritidis infection accelerated transmission of the organism to the uninfected hens in neighboring cages. These results indicate that induced molting can have substantial effects on transmission of S. enteritidis to uninfected hens, which could affect the overall S. enteritidis status of a flock.
研究了强制换羽对肠炎沙门氏菌水平传播的影响。在实验1中,将一排换羽母鸡和一排未换羽母鸡中的每隔一只母鸡感染肠炎沙门氏菌(每只母鸡1×10⁶个细菌)。与未换羽母鸡相比,肠炎沙门氏菌向换羽母鸡相邻笼中未受感染母鸡的传播速度更快,并且这些换羽母鸡排出的该微生物显著多于未换羽母鸡。在实验2和3中,在11只换羽母鸡和11只未换羽母鸡的两排中,每排的中间母鸡感染肠炎沙门氏菌(实验2中的剂量为6 - 8×10⁴,实验3中的剂量为1×10³)。在实验2的两次试验中,换羽母鸡的传播率均显著高于未换羽母鸡,并且换羽母鸡排出的该微生物显著更多。在实验3的试验1中,换羽对肠炎沙门氏菌的排出影响不大。然而,在实验3的试验2中,换羽母鸡的排出率显著更高,并且排出的肠炎沙门氏菌比未换羽母鸡更多。实验2和3中的个体母鸡排出的肠炎沙门氏菌常常比最初感染的更多。换羽母鸡肠道中肠炎沙门氏菌的增殖以及它们先前所述的对肠炎沙门氏菌感染更高的易感性加速了该微生物向相邻笼中未感染母鸡的传播。这些结果表明,强制换羽可对肠炎沙门氏菌向未感染母鸡的传播产生重大影响,这可能会影响鸡群的整体肠炎沙门氏菌状况。