Isah Abubakar Shitu, Ramachandran Reshma, Sukumaran Anuraj Theradiyil, Kiess Aaron S, Castañeda Claudia D, Boltz Tim, Macklin Kenneth, Abdelhamed Hossam, Zhang Li
Department of Poultry Science, Mississippi State University, MS, 39762.
IDEXX Laboratories, Westbrook, Maine 04092, New England.
Poult Sci. 2024 Dec;103(12):104351. doi: 10.1016/j.psj.2024.104351. Epub 2024 Sep 20.
Salmonella Reading (S. Reading) recently emerged as a foodborne pathogen causing extensive human outbreaks in North America from consuming contaminated poultry products, mostly from turkeys. Understanding the transmission dynamics of this pathogen is crucial for preventing future outbreaks. This study investigated the ability of S. Reading to colonize the tissues and contaminate eggs of broiler breeders. We utilized 2 S. Reading strains, marked with bioluminescence gene: the outbreak strain RS330 and a reference strain RS326. We used 32 commercially sourced broiler breeder hens, 34 wk of age, randomly assigned to the 2 treatments (16 hens per strain). Each hen was intravaginally inoculated with 10 CFU of the respective strain on d 1 and was rechallenged on d 4. Eggs were collected daily postchallenge to recover bioluminescent S. Reading strains from the external eggshell surface and internal egg contents. On d 7 postchallenge, 10 hens from each treatment group were euthanized. Ovaries, oviducts, and ceca were aseptically collected to detect S. Reading colonization. Results showed that 70.5% (36 of 51) and 34.5% (19 of 55) of external eggshell surfaces, and 4.0% (2 of 50) and 1.8% (1 of 54) of the internal egg contents tested positive for the outbreak and nonoutbreak strains. Additionally, 40.0% of ovaries, 70.0% of oviduct, and 70.0% of ceca samples from the outbreak strain group, and 20.0% of ovaries, 70.0% of oviduct, and 80.0% of ceca samples from nonoutbreak strain group were positive. No significant difference (P = 0.05) was observed in all the findings among the strains except for the eggshell surface contamination. These findings suggest that S. Reading can effectively colonize reproductive tissues, translocate to the ceca, and contaminate the eggs of hens. Future research is needed to determine whether S. Reading can remain viable within the eggs throughout incubation and until hatching.
雷丁沙门氏菌（S. Reading）最近作为一种食源性病原体出现，它通过食用受污染的家禽产品（主要是火鸡）在北美引发了多起大规模的人类疫情。了解这种病原体的传播动态对于预防未来的疫情至关重要。本研究调查了雷丁沙门氏菌在肉种鸡组织中定殖并污染鸡蛋的能力。我们使用了2株标记有生物发光基因的雷丁沙门氏菌菌株：疫情菌株RS330和参考菌株RS326。我们使用了32只34周龄的商业来源肉种鸡母鸡，随机分配到2种处理组（每种菌株16只母鸡）。每只母鸡在第1天经阴道接种10 CFU各自的菌株，并在第4天再次接种。攻毒后每天收集鸡蛋，以从蛋壳外表面和蛋内容物中回收发光的雷丁沙门氏菌菌株。攻毒后第7天，对每个处理组的10只母鸡实施安乐死。无菌采集卵巢、输卵管和盲肠以检测雷丁沙门氏菌的定殖情况。结果显示，疫情菌株和非疫情菌株检测中，分别有70.5%（51个中的36个）和34.5%（55个中的19个）的蛋壳外表面，以及4.0%（50个中的2个）和1.8%（54个中的1个）的蛋内容物呈阳性。此外，疫情菌株组中40.0%的卵巢、70.0%的输卵管和70.0%的盲肠样本，以及非疫情菌株组中20.0%的卵巢、70.0%的输卵管和80.0%的盲肠样本呈阳性。除蛋壳表面污染外，各菌株在所有检测结果中均未观察到显著差异（P = 0.05）。这些结果表明，雷丁沙门氏菌能够有效地在生殖组织中定殖，转移至盲肠，并污染母鸡的鸡蛋。未来需要开展研究以确定雷丁沙门氏菌在整个孵化期直至孵化前能否在鸡蛋内保持存活。
