INTRACELLULAR INFECTION BY INVASIVE GROUP A STREPTOCOCCI

20世纪80年代后期，全身性感染和 风湿热我们证明了一个旧的M血清型的新克隆， 与大多数严重疾病有关。这个克隆人拥有一个 噬菌体编码SPEA毒素和许多其他基因， 可能有助于其入侵表型。初步实验表明， 这种新的入侵性克隆增强了穿透人类的能力， 上皮细胞本项目的主要目的是了解 高毒力菌株倾向的分子基础 链球菌侵入血液并引起全身性疾病，如 如血管闭塞和风湿热我们将确认A组 链球菌可以穿透培养的人肺细胞并在其中生长， 最近出现的M1链球菌的侵袭性克隆能够更好地 相对于侵袭性较小的菌株，它们在人类细胞中的侵袭和繁殖能力更强。 我们将测试这些入侵菌株是否携带噬菌体DNA 基因编码的入侵表型，并试图克隆 负责任的基因并定义它们的产物。链球菌对 庆大霉素和青霉素与培养的上皮细胞联合， 该标准用作细胞内状态的量度。

The late 1980's witnessed a resurgence of both systemic infections and rheumatic fever. We demonstrated that a new clone of an old M serotype was associated with most cases of serious disease. This clone harbors a bacteriophage which encodes the SPEA toxin and many other genes which could contribute to its invasive phenotype. Preliminary experiments showed that this new invasive clone has enhanced capacity to penetrate human epithelial cells. The primary objective of this project is to understand the molecular basis for the propensity of highly virulent strains of group A streptococci to invade the blood stream and cause systemic disease, such as vascular occlusion and rheumatic fever. We will confirm that group A streptococci can penetrate and grow within cultured human lung cells and that the recently emerged invasive clone of M1 streptococci is better able to invade and multiply in human cells relative to less invasive strains. We will test whether bacteriophage DNA harbored by these invasive strains genetically encode for the invasive phenotype, and attempt to clone responsible genes and define their products. Resistance of streptococci to gentamicin and penicillin in association with cultured epithelial cells is the criterion used as a measure of the intracellular state.