PDF(Pubmed)
Abstract：
Eggs, an important part of a healthy daily diet, can protect chicken embryo development due to the shell barrier and various antibacterial components within the egg white. Our previous study demonstrated that Salmonella Pullorum, highly adapted to chickens, can survive in the egg white and, therefore, be passed to newly hatched chicks. However, the survival strategy of Salmonella Pullorum in antibacterial conditions remains unknown. The overall transcripts in the egg white showed a large-scale shift compared to LB broth. The expression of common response genes and pathways, such as those involved in iron uptake, biotin biosynthesis, and virulence, was significantly changed, consistent with the other transovarial transmission serovar Enteritidis. Notably, membrane stress response, amino acid metabolism, and carbohydrate metabolism were specifically affected. Additional upregulated functionally relevant genes (JI728_13095, JI728_13100, JI728_17960, JI728_10085, JI728_15605, and nhaA) as mutants confirmed the susceptible phenotype. Furthermore, fim deletion resulted in an increased survival capacity in the egg white, consistent with the downregulated expression. The second-round RNA-Seq analysis of the Δfim mutant in the egg white revealed significantly upregulated genes compared with the wild type in the egg white responsible for energy metabolism located on the hyc and hyp operons regulated by FhlA, indicating the Δfim mutant cannot receive enough oxygen and switched to fermentative growth due to its inability to attach to the albumen surface. Together, this study provides a first estimate of the global transcriptional response of Salmonella Pullorum under antibacterial egg white and highlights the new potential role of fim deletion in optimizing energy metabolism pathways that may assist vertical transmission.
OBJECTIVE: Pullorum disease, causing serious embryo death and chick mortality, results in substantial economic losses worldwide due to transovarial transmission. Egg-borne outbreaks are frequently reported in many countries. The present study has filled the knowledge gap regarding how the specific chicken-adapted pathogen Salmonella Pullorum behaves within the challenging environment of egg white. The deletion of the fim fimbrial system can increase survival in the albumen, possibly by reprogramming metabolism-related gene products, which reveals a new adaptive strategy of pathogens. Moreover, the comparison, including previous research on Salmonella Enteritidis, capable of vertical transmission, aims to provide diversified data sets in the field and further help to implement reasonable and effective measures to improve both food safety and animal health.
OBJECTIVE: Pullorum disease, causing serious embryo death and chick mortality, results in substantial economic losses worldwide due to transovarial transmission. Egg-borne outbreaks are frequently reported in many countries. The present study has filled the knowledge gap regarding how the specific chicken-adapted pathogen Salmonella Pullorum behaves within the challenging environment of egg white. The deletion of the fim fimbrial system can increase survival in the albumen, possibly by reprogramming metabolism-related gene products, which reveals a new adaptive strategy of pathogens. Moreover, the comparison, including previous research on Salmonella Enteritidis, capable of vertical transmission, aims to provide diversified data sets in the field and further help to implement reasonable and effective measures to improve both food safety and animal health.
摘要：
鸡蛋,健康日常饮食的重要组成部分，由于蛋清内的壳屏障和各种抗菌成分，可以保护鸡胚的发育。我们之前的研究表明，沙门氏菌，高度适应鸡，可以在蛋清中存活，因此,传给新孵化的小鸡。然而,沙门氏菌在抗菌条件下的生存策略仍然未知。与LB肉汤相比，蛋清中的整体转录物显示出大规模的变化。共同反应基因和途径的表达，比如那些参与铁摄取的，生物素生物合成，和毒力，发生了重大变化，与其他经静脉曲张传播血清型肠炎一致。值得注意的是,膜应激反应，氨基酸代谢，和碳水化合物代谢受到特别的影响。其他上调的功能相关基因（JI728_13095，JI728_13100，JI728_17960，JI728_10085，JI728_15605和nhaA）作为突变体证实了易感表型。此外，fim缺失导致蛋清的生存能力增加，与表达下调一致。蛋清中Δfim突变体的第二轮RNA-Seq分析显示，与蛋清中负责能量代谢的野生型相比，基因显着上调，位于FhlA调节的hyc和hyp操纵子上，表明Δfim突变体由于无法附着在蛋白表面而无法接受足够的氧气并转为发酵生长。一起,这项研究首次评估了在抗菌蛋清作用下沙门氏菌的整体转录反应，并强调了fim缺失在优化可能有助于垂直传播的能量代谢途径方面的新潜在作用。
目的：鸡白肠病，导致严重的胚胎死亡和小鸡死亡，由于经血管传播，在全球范围内造成了巨大的经济损失。许多国家经常报道鸡蛋传播的疫情。本研究填补了有关特定的鸡适应病原体鸡沙门氏菌在具有挑战性的蛋清环境中的行为的知识空白。毛皮系统的缺失可以增加蛋白的存活率，可能通过重新编程与代谢相关的基因产物，这揭示了一种新的病原体适应性策略。此外，比较,包括先前对肠炎沙门氏菌的研究，能够垂直传输，旨在提供该领域的多元化数据集，并进一步帮助实施合理有效的措施，以改善食品安全和动物健康。
目的：鸡白肠病，导致严重的胚胎死亡和小鸡死亡，由于经血管传播，在全球范围内造成了巨大的经济损失。许多国家经常报道鸡蛋传播的疫情。本研究填补了有关特定的鸡适应病原体鸡沙门氏菌在具有挑战性的蛋清环境中的行为的知识空白。毛皮系统的缺失可以增加蛋白的存活率，可能通过重新编程与代谢相关的基因产物，这揭示了一种新的病原体适应性策略。此外，比较,包括先前对肠炎沙门氏菌的研究，能够垂直传输，旨在提供该领域的多元化数据集，并进一步帮助实施合理有效的措施，以改善食品安全和动物健康。
