Otten S, Iyer S, Johnson W, Montgomery R
J Bacteriol. 1986 Sep;167(3):893-904. doi: 10.1128/jb.167.3.893-904.1986.
Serospecific antigens isolated by EDTA extraction from four serogroups of Legionella pneumophila were analyzed for their chemical composition, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The antigens were shown to be lipopolysaccharides and to differ from the lipopolysaccharides of other gram-negative bacteria. The serospecific antigens contained rhamnose, mannose, glucosamine, and two unidentified sugars together with 2-keto-3-deoxyoctonate, phosphate, and fatty acids. The fatty acid composition was predominantly branched-chain acids with smaller amounts of 3-hydroxymyristic acid. The antigens contain periodate-sensitive groups; mannosyl residues were completely cleaved by periodate oxidation. Hydrolysis of the total lipopolysaccharide by acetic acid resulted in the separation of a lipid A-like material that cross-reacted with the antiserum to lipid A from Salmonella minnesota but did not comigrate with it on sodium dodecyl sulfate gels. None of the four antigens contained heptose. All of the antigen preparations showed endotoxicity when tested by the Limulus amebocyte lysate assay. The results of this study indicate that the serogroup-specific antigens of L. pneumophila are lipopolysaccharides containing an unusual lipid A and core structure and different from those of other gram-negative bacteria.
通过乙二胺四乙酸（EDTA）提取法从嗜肺军团菌的四个血清群中分离出的血清特异性抗原，对其化学组成、通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析的分子异质性以及免疫学特性进行了分析。结果表明，这些抗原为脂多糖，且与其他革兰氏阴性菌的脂多糖不同。血清特异性抗原含有鼠李糖、甘露糖、葡糖胺和两种未鉴定的糖，以及2-酮-3-脱氧辛酸、磷酸盐和脂肪酸。脂肪酸组成主要为支链酸，3-羟基肉豆蔻酸含量较少。这些抗原含有对高碘酸盐敏感的基团；甘露糖基残基通过高碘酸盐氧化被完全裂解。用乙酸水解总脂多糖，可分离出一种类似脂质A的物质，该物质与来自明尼苏达沙门氏菌的脂质A抗血清发生交叉反应，但在十二烷基硫酸钠凝胶上与其迁移位置不同。这四种抗原均不含庚糖。通过鲎试剂法检测时，所有抗原制剂均显示出内毒素活性。本研究结果表明，嗜肺军团菌的血清群特异性抗原是含有不寻常脂质A和核心结构的脂多糖，与其他革兰氏阴性菌的脂多糖不同。
