Rhodococcus equi is an intracellular veterinary pathogen that is becoming resistant to current antibiotherapy. Genes involved in preserving redox homeostasis could be promising targets for the development of novel anti-infectives. Here, we studied the role of an extracellular thioredoxin (Etrx3/REQ_13520) in the resistance to phagocytosis. An etrx3-null mutant strain was unable to survive within macrophages, whereas the complementation with the etrx3 gene restored its intracellular survival rate. In addition, the deletion of etrx3 conferred to R. equi a high susceptibility to sodium hypochlorite. Our results suggest that Etrx3 is essential for the resistance of R. equi to specific oxidative agents.

中文翻译：

---

马红球菌感染巨噬细胞需要胞外硫氧还蛋白Etrx3。

马红球菌是一种细胞内兽医病原体，对目前的抗生物疗法有抵抗力。参与维持氧化还原稳态的基因可能是开发新型抗感染药的有希望的靶标。在这里，我们研究了细胞外硫氧还蛋白（Etrx3 / REQ_13520）在对吞噬作用的抗性中的作用。一个etrx3-null突变株无法在巨噬细胞中生存，而与etrx3基因的互补恢复了其细胞内存活率。此外，etrx3的缺失使R. equi对次氯酸钠具有很高的敏感性。我们的结果表明，Etrx3对马鞭草对特定氧化剂的抗性至关重要。