Isolation, structural characterization, and immunological evaluation of a high-molecular-weight exopolysaccharide from Staphylococcus aureus
Isolation, structural characterization, and immunological evaluation of a high-molecular-weight exopolysaccharide from Staphylococcus aureus
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DOI：
10.1016/s0008-6215(03)00045-4
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发表时间：
2003-04-22
影响因子：
3.1
通讯作者：
Mark, GE
中科院分区：
文献类型：
--
作者：
Joyce, JG;Abeygunawardana, C;Mark, GE
凝固酶阴性葡萄球菌（如表皮葡萄球菌）对植入医疗器械的定植是由细菌多糖细胞间粘附素（PIA）介导的，PIA是一种β -(1 - bbb6)-连接的氨基葡萄糖聚合物，被n -乙酰基和o -琥珀基成分取代。在表皮葡萄球菌和金黄色葡萄球菌中都发现了含有生产PIA的生物合成基因的icaADBC位点。虽然很明显PIA是表皮葡萄球菌毒力的组成部分，但PIA在金黄色葡萄球菌感染中的作用尚不清楚。最近，从金黄色葡萄球菌中鉴定出一种新的多糖抗原，称为聚n -琥珀酰β -(1—bbb6)-氨基葡萄糖（PNSG）。该聚合物由与PIA相同的聚糖主链组成，但据报道含有高比例的n -琥珀酰化而不是乙酰化。我们从组成型过量生产的金黄色葡萄球菌MN8m菌株中分离出一种含葡萄糖胺的外多糖，以制备多糖-蛋白结合疫苗。在本报告中，我们证明了MN8m产生了高分子量（bbb30万Da）的β -(1 - bbb6)-连接葡萄糖胺聚合物，其中含有45 - 60%的n -乙酰基和少量的o -琥珀基（单糖单位的摩尔比约为10%）。通过对多糖制剂的详细核磁共振分析，我们表明，之前鉴定的n -琥珀酰是一个分析伪影。我们分离的外多糖在体外血凝试验中具有活性，当与蛋白质载体偶联时，在小鼠中具有免疫原性。因此，我们得出结论，金黄色葡萄球菌菌株MN8m产生的聚合物在化学和生物学上与表皮葡萄球菌产生的PIA密切相关。2003爱思唯尔科学有限公司版权所有。
Colonization of implanted medical devices by coagulase-negative staphylococci such as Staphylococcus epidermidis is mediated by the bacterial polysaccharide intercellular adhesin (PIA), a polymer of beta-(1 --> 6)-linked glucosamine substituted with N-acetyl and O-succinyl constituents. The icaADBC locus containing the biosynthetic genes for production of PIA has been identified in both S. epidermidis and S. aureus. Whereas it is clear that PIA is a constituent that contributes to the virulence of S. epidermidis, it is less clear what role PIA plays in infection with S. aureus. Recently, identification of a novel polysaccharide antigen from S. aureus termed poly N-succinyl beta-(1 --> 6)-glucosamine (PNSG) has been reported. This polymer was composed of the same glycan backbone as PIA but was reported to contain a high proportion of N-succinylation rather than acetylation. We have isolated a glucosamine-containing exopolysaccharide from the constitutive over-producing MN8m strain of S. aureus in order to prepare polysaccharide-protein conjugate vaccines. In this report we demonstrate that MN8m produced a high-molecular-weight (> 300,000 Da) polymer of beta-(1 --> 6)-linked glucosamine containing 45 - 60% N-acetyl, and a small amount of O-succinyl (approx 10% mole ratio to monosaccharide units). By detailed NMR analyses of polysaccharide preparations, we show that the previous identification of N-succinyl was an analytical artifact. The exopolysaccharide we have isolated is active in in vitro hemagglutination assays and is immunogenic in mice when coupled to a protein carrier. We therefore conclude that S. aureus strain MN8m produces a polymer that is chemically and biologically closely related to the PIA produced by S. epidermidis. (C) 2003 Elsevier Science Ltd. All rights reserved.