Veterinary Research Institute, Hudcova 70, 621 00 Brno, Czech Republic.
Vet Microbiol. 2012 Apr 23;156(1-2):127-35. doi: 10.1016/j.vetmic.2011.10.004. Epub 2011 Oct 12.
Pigs are considered as one of the major sources of zoonotic strains of Salmonella enterica for humans. Out of many S. enterica serovars, S. Typhimurium dominates in pigs, however, in several countries in Central Europe, S. Enteritidis is also quite frequent in pig herds. In this study we therefore compared the colonisation of pigs with S. Typhimurium and S. Enteritidis. We found that 3 weeks after infection S. Enteritidis 147 colonised the intestinal tract in higher quantities but was shed in faeces in lower quantities than S. Typhimurium 17C10. In a second experiment we found out that S. Enteritidis 147 and its SPI-1 and SPI-4 mutants increased proinflammatory cytokine (IL-1β and IL-8) signalling in the ileum 5 days post infection. On the other hand, independent of SPI-1 or SPI-4, S. Enteritidis 147 suppressed expression of IL-18, MCP1, TLR2, CD86, IL-7, IL-10 and IL-15 in the palatine tonsils. The suppression of cytokine signalling may facilitate the initial colonisation of the palatine tonsils by Salmonella. Moreover, immune suppression may also influence pig resistance to opportunistic pathogens and Salmonella infection in pigs thus may become an issue not only in terms of pork contamination but also in terms of affecting the immunological status of pig herds.
猪被认为是人类沙门氏菌肠亚种的主要动物传染源之一。在许多沙门氏菌血清型中，鼠伤寒沙门氏菌在猪群中占优势，但在中欧的几个国家，肠炎沙门氏菌在猪群中也相当频繁。在本研究中，我们比较了猪感染鼠伤寒沙门氏菌和肠炎沙门氏菌的情况。我们发现，感染后 3 周，肠炎沙门氏菌 147 在肠道中的定植量较高，但粪便中的排出量低于鼠伤寒沙门氏菌 17C10。在第二个实验中，我们发现肠炎沙门氏菌 147 及其 SPI-1 和 SPI-4 突变株在感染后 5 天增加了回肠中的促炎细胞因子（IL-1β 和 IL-8）信号。另一方面，肠炎沙门氏菌 147 独立于 SPI-1 或 SPI-4，抑制了腭扁桃体中 IL-18、MCP1、TLR2、CD86、IL-7、IL-10 和 IL-15 的表达。细胞因子信号的抑制可能促进了沙门氏菌对腭扁桃体的初始定植。此外，免疫抑制也可能影响猪对机会性病原体和沙门氏菌感染的抵抗力，因此，这不仅是猪肉污染的问题，也会影响猪群的免疫状态。
