Departamento de Análises Clínicas e Toxicológicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
Mem Inst Oswaldo Cruz. 2010 Sep;105(6):786-91. doi: 10.1590/s0074-02762010000600009.
Enteroinvasive Escherichia coli (EIEC) and Shigella spp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigella share many genetic and biochemical similarities, the illness caused by Shigella is more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneri with cultured J774 macrophage-like cells. We evaluated several phenotypes: (i) bacterial escape from macrophages after phagocytosis, (ii) macrophage death induced by EIEC and S. flexneri, (iii) macrophage cytokine expression in response to infection and (iv) expression of plasmidial (pINV) virulence genes. The results showed that S. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri.
肠侵袭性大肠杆菌（EIEC）和志贺氏菌属通过侵袭和在结肠黏膜上皮细胞内繁殖引起人类细菌性痢疾。尽管 EIEC 和志贺氏菌属具有许多遗传和生化相似性，但志贺氏菌属引起的疾病更为严重。因此，对这些侵袭性肠杆菌与真核细胞的生物学相互作用的基因组和结构-功能分子研究主要集中在志贺氏菌属上，而不是 EIEC 上。在这里，我们比较研究了 EIEC 和福氏志贺菌与培养的 J774 巨噬样细胞的相互作用。我们评估了几种表型：（i）吞噬后细菌从巨噬细胞中逃逸，（ii）EIEC 和 S. flexneri 诱导的巨噬细胞死亡，（iii）感染后巨噬细胞细胞因子的表达和（iv）质粒（pINV）毒力基因的表达。结果表明，福氏志贺菌比 EIEC 更早、更强烈地引起巨噬细胞杀伤。两种病原体在感染 7 小时后均诱导显著的巨噬细胞产生 TNF、IL-1 和 IL-10。在整个感染过程中，EIEC 中侵袭质粒抗原-C 基因的转录水平均低于 S. flexneri；这可以解释 EIEC 相对于 S. flexneri 的毒力降低。
