Involvement of Enterotoxins G and I in Staphylococcal Toxic Shock Syndrome and Staphylococcal Scarlet Fever

We investigated the involvement of the recently described staphylococcal enterotoxins G and I in toxic shock syndrome. We reexamined Staphylococcus aureus strains isolated from patients with menstrual and nonmenstrual toxic shock syndrome (nine cases) or staphylococcal scarlet fever (three cases). These strains were selected because they produced none of the toxins known to be involved in these syndromes (toxic shock syndrome toxin 1 and enterotoxins A, B, C, and D), enterotoxin E or H, or exfoliative toxin A or B, despite the fact that superantigenic toxins were detected in a CD69-specific flow cytometry assay measuring T-cell activation. Sets of primers specific to the enterotoxin G and I genes (seg and sei, respectively) were designed and used for PCR amplification. All of the strains were positive for seg and sei. Sequence analysis confirmed that the PCR products, corresponded to the target genes. We suggest that staphylococcal enterotoxins G and I may be capable of causing human staphylococcal toxic shock syndrome and staphylococcal scarlet fever.

本研究探讨了新近报道的葡萄球菌肠毒素G和I（staphylococcal enterotoxins G and I）在中毒性休克综合征中的致病关联。我们对分离自月经性及非月经性中毒性休克综合征患者（9例）或葡萄球菌性猩红热患者（3例）的金黄色葡萄球菌（Staphylococcus aureus）菌株进行了重新分析。筛选这些菌株的依据为：尽管通过检测T细胞活化的CD69特异性流式细胞术可检出超抗原毒素，但上述菌株并未产生已知与此类综合征相关的各类毒素——包括中毒性休克综合征毒素1、肠毒素A、B、C、D，肠毒素E或H，以及剥脱性毒素A或B。我们设计了针对肠毒素G和I基因（分别为seg和sei）的特异性引物，并将其用于聚合酶链反应（PCR）扩增。所有菌株的seg和sei检测均呈阳性。序列分析证实，所得PCR扩增产物与目标基因序列完全匹配。本研究提示，葡萄球菌肠毒素G和I可能具备引发人类中毒性休克综合征及葡萄球菌性猩红热的致病能力。