Department of Biology, University of Richmond, Richmond, VA 23173, United States.
Microbiol Res. 2012 Apr 20;167(4):238-45. doi: 10.1016/j.micres.2011.09.004. Epub 2011 Oct 19.
Shigella flexneri, a facultative intracellular pathogen, is exposed to a variety of environments inside and outside of the human host. Some of these environments may contain significant oxidative stress. S. flexneri mutants were generated with deletions in the major oxidative stress regulators oxyR and/or soxRS to test their importance in Shigella biology. Strains that contained a deletion of oxyR had reduced growth and survival during aerobic growth, but not microaerobic growth. The mutants were also defective in surviving exposure to oxidative stress: oxyR mutants were sensitive to hydrogen peroxide, while soxRS mutants were sensitive to superoxide. Although the ΔsoxRS, ΔoxyR, and ΔoxyR/ΔsoxRS mutant Shigellae survived similarly to the parental strains within macrophages, the mutants formed plaques on Henle cell monolayers that were slightly smaller than the plaques formed by the wildtype strain.
福氏志贺菌是一种兼性细胞内病原体，它在人体宿主内外的各种环境中暴露。其中一些环境可能含有显著的氧化应激。本研究通过缺失主要氧化应激调节剂 oxyR 和/或 soxRS 来生成福氏志贺菌突变体，以测试它们在志贺菌生物学中的重要性。含有 oxyR 缺失的菌株在有氧生长过程中生长和存活减少，但在微需氧生长中没有减少。突变体在暴露于氧化应激时也存在缺陷：oxyR 突变体对过氧化氢敏感，而 soxRS 突变体对超氧阴离子敏感。尽管 ΔsoxRS、ΔoxyR 和 ΔoxyR/ΔsoxRS 突变的福氏志贺菌在巨噬细胞内与亲本菌株的存活情况相似，但突变体在 Henle 细胞单层上形成的噬菌斑比野生型菌株形成的噬菌斑略小。
