Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
mSphere. 2021 Jan 27;6(1):e01153-20. doi: 10.1128/mSphere.01153-20.
causes significant infections, responsible for toxic shock syndrome (TSS), hemorrhagic pneumonia, and many other infections. secretes virulence factors, which include superantigens such as staphylococcal enterotoxins (SEs). We examined differences in immunobiological activities and disease associations among the four human SEC subtypes. We sequenced the gene from 35 human isolates to determine SEC subtypes. Upon finding differences in disease association, we used a [H]thymidine uptake assay to examine SEC-induced superantigenicity. We also employed a rabbit model of SEC-induced TSS. SEC-2 and SEC-3 were associated with menstrual TSS and vaginal isolates from healthy women, whereas SEC-4 was produced by USA400 isolates causing purpura fulminans and hemorrhagic pneumonia. SEC subtypes differed in potency in a TSS rabbit model and in superantigenicity. There was no difference in superantigenicity when tested on human peripheral blood mononuclear cells. Despite differences, all SECs reacted with polyclonal antibodies raised against the other SEC subtypes. The associations of SEC subtypes with different infections suggest that produces virulence factors according to host niches. Staphylococcal enterotoxin C has four subtypes that cause human diseases, designated SEC-1 to -4. This study shows that SEC-2 and SEC-3 are the most toxic subtypes in a rabbit model and are associated with human vaginal infections or colonization in association with another superantigen, toxic shock syndrome toxin 1. SEC-4 is associated with purpura fulminans and hemorrhagic pneumonia. SEC-1 is uncommon. The data suggest that there is some selective pressure for the SEC subtypes to be associated with certain human niches.
导致严重感染，引起中毒性休克综合征（TSS）、出血性肺炎等多种感染。分泌毒力因子，包括葡萄球菌肠毒素（SEs）等超抗原。我们研究了 4 种人类 SEC 亚型在免疫生物学活性和疾病相关性方面的差异。我们从 35 个人类分离株中测序了 基因，以确定 SEC 亚型。在发现疾病相关性差异后，我们使用[H]胸腺嘧啶摄取测定法来检测 SEC 诱导的超抗原性。我们还采用了 SEC 诱导 TSS 的兔模型。SEC-2 和 SEC-3 与月经 TSS 和健康女性阴道分离株有关，而 SEC-4 则由引起暴发性紫癜和出血性肺炎的 USA400 分离株产生。SEC 亚型在 TSS 兔模型中的效力和超抗原性方面存在差异。在测试人类外周血单核细胞时，超抗原性没有差异。尽管存在差异，但所有 SEC 都与针对其他 SEC 亚型产生的多克隆抗体反应。SEC 亚型与不同感染的关联表明，根据宿主小生境产生毒力因子。葡萄球菌肠毒素 C 有 4 种亚型会引起人类疾病，分别命名为 SEC-1 到 -4。本研究表明，SEC-2 和 SEC-3 是兔模型中毒性最强的亚型，与人类阴道感染或与另一种超抗原毒性休克综合征毒素 1 有关的定植有关。SEC-4 与暴发性紫癜和出血性肺炎有关。SEC-1 比较少见。这些数据表明，SEC 亚型与某些人类小生境相关存在一定的选择性压力。
