BIOCHEMISTRY OF STAPHYLOCOCCAL EXOPOLYSACCHARIDES

某些凝固酶阳性菌株（金黄色葡萄球菌）和 凝固酶阴性（例如，表皮葡萄球菌 被称为胶囊和粘液的胞外多糖。 胶囊和粘液是 形态和化学上不同的聚合物结构。 胶囊 与细菌细胞表面的联系比粘液更紧密。 两 荚膜和粘液是毒力因子，因为荚膜允许菌株 抵抗吞噬作用，并且粘液促进葡萄球菌的粘附。 了解胶囊的化学结构，特别是黏液， 处于相对初级的阶段。 没有深入系统的研究， 已经报道了荚膜和粘液产生的生理学。 小 信息是可利用的遗传学和控制胶囊和粘液 多糖，或生物活性或宿主对这些多糖的反应， 聚合物 这一建议是通过研究来开拓这一领域的研究 葡萄球菌荚膜和粘液的生理学和化学。 的 建议的具体目标是：㈠采用最佳方法， 分离和纯化荚膜和粘液多糖;（ii）确定 化学成分和结构的选择分离和纯化 荚膜和粘液多糖;（iii）检查 生长培养基的组成和培养条件对生产的影响 的荚膜和粘液多糖，以确定关键成分， 选择的葡萄球菌菌株的多糖生产。

Certain strains of coagulase-positive (Staphylococcus aureus) and coagulase-negative (e.g., Staphylococcus epidermidis) staphylococci produce exopolysaccharides known as capsules and slimes. Capsules and slimes are morphologically and chemically distinct polymeric structures. Capsules are more firmly associated with the bacterial cell surface than slimes. Both capsules and slimes are virulence factors in that capsules allow strains to resist phagocytosis, and slimes promote adherence of staphylococci. Knowledge of the chemical structure of capsules, and slimes in particular, is at a relatively rudimentary stage. No in depth systematic studies on the physiology of capsule and slime production have been reported. Little information is available on the genetics and control of capsule and slime polysaccharides, or on the biological activities or host response to these polymers. This proposal is to open up the study of this area through study of the physiology and chemistry of staphylococcal capsules and slimes. The specific aims of the proposal are to: (i) employ optimal methods to isolate and purify capsular and slime polysaccharides; (ii) determine the chemical composition and structure of selected isolated and purified capsular and slime polysaccharides; (iii) examine the influence of the composition of the growth medium and cultural conditions on the production of capsular and slime polysaccharides to identify key components promoting polysaccharide production in selected staphylococcal strains.