Excessive iron in the bacterial cytoplasm can potentiate the production of harmful reactive oxygen species (ROS). Riemerella anatipestifer (R. anatipestifer, RA), a gram-negative bacterium, encodes an iron uptake system, but its iron detoxification mechanism is unknown. Here, the dps gene of R. anatipestifer CH-1 (RA-CH-1) was deleted using sacB as a counterselection marker. The dps mutant was more sensitive to H₂O₂ than the wild type in iron-rich conditions but not in iron-limited conditions, suggesting that Dps prevents H₂O₂-induced damage through iron binding. However, the dps mutant and wild type were identically sensitive to bactericidal antibiotics, and antibiotic treatment did not enhance RA-CH-1 ROS production. Furthermore, Dps prevents DNA damage by binding DNA. The RA-CH-1 dps transcript level was higher in the stationary phase than in the early and exponential phases and was increased by OxyR in the presence of H₂O₂. Finally, duckling colonization by the dps mutant was similar to that by the wild type at 48 h postinfection but significantly lower at 60 h postinfection, suggesting that RA-CH-1 Dps is not involved in host invasion but increases resistance to host clearance. Dps thus likely plays an important role in R. anatipestifer physiology and pathogenesis through protecting against oxidative stress.

细菌细胞质中过量的铁会增强有害活性氧（ROS）的产生。革兰氏阴性细菌Riemerella anatipestifer（R. anatipestifer，RA）编码铁吸收系统，但其铁排毒机制尚不清楚。在此，使用sacB作为反选择标记，删除了R. anatipestifer CH-1（RA-CH-1）的dps基因。该DPS突变体与H更敏感₂ ö ₂比富含铁的条件下，野生型而不是在铁限制的条件下，这表明的Dps防止ħ ₂ ö ₂诱导的通过铁损伤结合。然而dps突变体和野生型对杀菌抗生素具有相同的敏感性，并且抗生素处理不能提高RA-CH-1 ROS的产生。此外，Dps通过结合DNA来防止DNA损伤。固定相的RA-CH-1 dps转录水平高于早期和指数相，并且在H ₂ O ₂存在下被OxyR升高。最后，dps突变体的小鸭定植与野生型在感染后48 h相似，但在感染后60 h明显降低，这表明RA-CH-1 Dps不参与宿主入侵，但增加了对宿主清除的抵抗力。因此，Dps可能在拟南芥中起重要作用 通过预防氧化应激的生理和发病机理。