Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
FEMS Microbiol Lett. 2011 Mar;316(1):1-6. doi: 10.1111/j.1574-6968.2010.02186.x. Epub 2011 Jan 10.
Brucella abortus has been shown to produce two siderophores: 2,3-dihydroxybenzoic acid (2,3-DHBA) and brucebactin. Previous studies on Brucella have shown that 2,3-DHBA is associated with erythritol utilization and virulence in pregnant ruminants. The biosynthetic pathway and role of brucebactin are not known and the only gene shown to be involved so far is entF. Using cre-lox methodology, an entF mutant was created in wild-type B. abortus 2308. Compared with the wild-type strain, the ΔentF strain showed significant growth inhibition in iron minimal media that became exacerbated in the presence of an iron chelator. For the first time, we have demonstrated the death of the ΔentF strain under iron-limiting conditions in the presence of erythritol. Addition of FeCl(3) restored the growth of the ΔentF strain, suggesting a significant role in iron acquisition. Further, complementation of the ΔentF strain using a plasmid containing an entF gene suggested the absence of any polar effects. In contrast, there was no significant difference in survival and growth between the ΔentF and wild-type strains grown in the murine macrophage cell line J774A.1, suggesting that an alternate iron acquisition pathway is present in Brucella when grown intracellulary.
2,3-二羟基苯甲酸（2,3-DHBA）和布鲁氏菌素。以前对布鲁氏菌的研究表明，2,3-DHBA 与妊娠反刍动物的赤藓糖醇利用和毒力有关。布鲁氏菌素的生物合成途径和作用尚不清楚，到目前为止，唯一显示参与的基因是 entF。使用 cre-lox 方法，在野生型 B.abortus 2308 中创建了 entF 突变体。与野生型菌株相比，ΔentF 菌株在铁最低培养基中的生长受到明显抑制，而在铁螯合剂存在下则更为严重。我们首次在铁限制条件下并在赤藓糖醇存在下证明了ΔentF 菌株的死亡。添加 FeCl3恢复了ΔentF 菌株的生长，表明其在铁获取中具有重要作用。此外，使用含有 entF 基因的质粒对ΔentF 菌株进行互补表明不存在任何极性效应。相比之下，在鼠巨噬细胞系 J774A.1 中生长时，ΔentF 菌株和野生型菌株的存活和生长之间没有显着差异，这表明布鲁氏菌在细胞内生长时存在替代的铁获取途径。
