The Salmonella pathogenicity island 1 and Salmonella pathogenicity island 2 type III secretion systems play a major role in pathogenesis of systemic disease and gastrointestinal tract colonization of Salmonella enterica serovar Typhimurium in the chicken
The Salmonella pathogenicity island 1 and Salmonella pathogenicity island 2 type III secretion systems play a major role in pathogenesis of systemic disease and gastrointestinal tract colonization of Salmonella enterica serovar Typhimurium in the chicken
复制标题
DOI：
10.1080/03079450701264118
复制
发表时间：
2007-06-01
期刊：
影响因子：
2.8
通讯作者：
Wigley, Paul
中科院分区：
文献类型：
--
作者：
Jones, Michael A.;Hulme, Scott D.;Wigley, Paul
鸡的沙门氏菌感染是一个重大的公共和动物卫生问题。幼雏S.鼠伤寒感染导致严重的全身感染;在较老的鸡中，感染导致胃肠道定植延长。本研究通过实验性感染鸡沙门氏菌，探讨了沙门氏菌致病岛1（SPI-1）和沙门氏菌致病岛2（SPI-2）III型分泌系统在鸡全身感染和胃肠道定植中的作用。在编码SPI-1（spaS）和SPI-2（ssaU）分泌系统机制的基因中具有突变的鼠伤寒沙门氏菌菌株，其阻止效应蛋白的分泌。在1日龄雏鸡中，SPI-2突变导致全身细菌数量和病理学的减少，但未观察到胃肠道数量的差异。SPI-1基因突变对1日龄雏鸡的影响不大。在1周龄的动物中，SPI-2突变体不能被全身检测到，并且与亲本菌株相比仅以低数量定殖在胃肠道中，并且在1周内被清除。SPI-1突变体表现出大大降低的全身感染水平，并以低于亲本菌株的水平定殖胃肠道。结果表明，SPI-2 III型分泌系统是系统性S.在两种感染模型中鼠伤寒杆菌感染，并且它在胃肠道定植中起重要作用。SPI-1系统参与全身性感染和胃肠道定植，但似乎不是绝对必要的感染过程。
Salmonella enterica serovar Typhimurium infection of chickens is a major public and animal health problem. In young chicks, S. Typhimurium infection results in severe systemic infection; in older chicks, infection results in prolonged gastrointestinal tract colonization. Here we determined the role of the Salmonella pathogenicity island 1 (SPI-1) and Salmonella pathogenicity island 2 (SPI-2) type III secretion systems in systemic infection and gastrointestinal tract colonization of the chicken though experimental infection of chicks with a S. Typhimurium strain with mutations in the genes encoding the secretion system machinery of SPI-1 (spaS) and SPI-2 (ssaU) that prevent secretion of effector proteins. In 1-day-old chicks, mutation of SPI-2 lead to a decrease in both systemic bacterial numbers and pathology, although no difference in gastrointestinal numbers was observed. Mutation of SPI-1 had little effect in 1-day old chicks. In 1-week-old animals the SPI-2 mutants could not be detected systemically and colonized the gastrointestinal tract only in low numbers in comparison with the parent strain, and was cleared in I week. The SPI-1 mutant showed greatly reduced levels of systemic infection, and colonized the gastrointestinal tract at a lower level than the parent strain. The findings show that the SPI-2 type III secretion system is required for systemic S. Typhimurium infection in both infection models, and that it plays a significant role in gastrointestinal colonization. The SPI-1 system is involved in both systemic infection and gastrointestinal colonization, but does not appear absolutely essential for either infection process.