Staphylococcal enterotoxin B (SEB), which is produced by the major human pathogen, Staphylococcus aureus, represents a powerful superantigenic toxin and is considered a bioweapon. However, the contribution of SEB towards S. aureus pathogenesis has never been directly demonstrated with genetically defined mutants in clinically relevant strains. Many isolates of the predominant Asian community-associated methicillin-resistant S. aureus (CA-MRSA) lineage ST59 harbor seb, implying a significant role of SEB in the observed hypervirulence of this lineage. We created an isogenic seb mutant in a representative ST59 isolate and assessed its virulence potential in mouse infection models. We detected a significant contribution of seb to systemic ST59 infection that was associated with a cytokine storm. Our results directly demonstrate that seb contributes to S. aureus pathogenesis, suggesting value of including SEB as a target in multi-pronged anti-staphylococcal drug development strategies. Furthermore, they indicate that seb contributes to fatal exacerbation of CA-MRSA infection.

中文翻译：

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葡萄球菌肠毒素 B 有助于金黄色葡萄球菌全身感染。

由主要人类病原体金黄色葡萄球菌产生的葡萄球菌肠毒素 B (SEB) 是一种强大的超抗原毒素，被认为是一种生物武器。然而，SEB 对金黄色葡萄球菌发病机制的贡献从未在临床相关菌株中用基因定义的突变体直接证明。主要亚洲社区相关的耐甲氧西林金黄色葡萄球菌(CA-MRSA) 谱系 ST59的许多分离株都含有seb，这意味着 SEB 在观察到的该谱系的高毒力中具有重要作用。我们创建了一个等基因seb在代表性的 ST59 分离株中发现突变体，并评估了其在小鼠感染模型中的毒力潜力。我们检测到 seb 对与细胞因子风暴相关的全身性 ST59 感染的显着贡献。我们的研究结果直接表明，seb有助于金黄色葡萄球菌的发病机制，表明将 SEB 作为多管齐下的抗葡萄球菌药物开发策略中的靶点的价值。此外，他们指出，seb有助于 CA-MRSA 感染的致命恶化。