Department of Bacteriology, Statens Bakteriologiska Laboratorium, Stockholm, Sweden.
Infect Immun. 1970 Jan;1(1):88-97. doi: 10.1128/iai.1.1.88-97.1970.
The phage adsorption ability and serological specificity of different Salmonella strains having either complete or leaky mutations in their lipopolysaccharide (LPS) synthesis were compared, together with their genotype and sugar composition, to provide a set of standards relating these parameters to LPS structure. Strains that had T1-specific side chains in their LPS, both with or without O side chains, were examined to learn more about the organization of these two side chains in the LPS and a possible competition between them. It was found that (i) adsorption of O-specific antibodies was a very sensitive test for the presence of even very small amounts of O-specific structures, (ii) that phage P22 adsorption was dependent on the presence of a nearly complete O side chain complement, and both long and numerous O side chains were required, and (iii) that the adsorption of the phages FO (Felix O-1), 6SR, and Br2, which attach to structures in the LPS core, was a sensitive indicator of any defect in O-antigen synthesis, and well developed O side chains blocked their attachment efficiently. Semirough (SR) strains with only one O-specific repeating unit per side chain adsorbed FO efficiently, whereas the access of the 6SR and Br2 phages to their receptors was blocked. Strains with T1 side chains adsorbed the FO and 6SR phages efficiently, whereas the adsorption of the Br2 phage was blocked to a large extent. The phage adsorption of four S, T1 strains (with both O and T1 side chains) showed that, as the amount of O side chain material increased, there was a reduction of the adsorption of phages in the following order: 6SR, Br2, and FO. P22 attachment appeared with the increase of O side chains. The LPS composition of these strains revealed a 10-fold reduction of the O-specific structures compared to the smooth parent strain, whereas the amount of T1-specific material was the same as in T1 strains. The short O side chains of a SR, T1 strain were, however, not reduced in number, suggesting that the apparent competition between O and T1 side chains may not be a competition for available sites in the LPS.
比较了具有完整或渗漏突变的脂多糖（LPS）合成的不同沙门氏菌菌株的噬菌体吸附能力和血清学特异性，以及它们的基因型和糖组成，以提供一套将这些参数与 LPS 结构相关联的标准。检查了 LPS 中具有 T1 特异性侧链的菌株，无论是带有 O 侧链还是没有 O 侧链，以了解这两种侧链在 LPS 中的组织以及它们之间可能的竞争。结果发现：（i）O 特异性抗体的吸附是检测 O 特异性结构存在的非常敏感的测试，即使是非常少量的 O 特异性结构也能检测到；（ii）噬菌体 P22 的吸附取决于 O 侧链几乎完整的互补，并且需要长而众多的 O 侧链；（iii）噬菌体 FO（费利克斯 O-1）、6SR 和 Br2 的吸附，它们附着在 LPS 核心中的结构上，是 O 抗原合成任何缺陷的敏感指标，并且发育良好的 O 侧链有效地阻止了它们的附着。每条侧链只有一个 O 特异性重复单元的半粗糙（SR）菌株有效地吸附 FO，而 6SR 和 Br2 噬菌体进入其受体的通道被阻断。具有 T1 侧链的菌株有效地吸附 FO 和 6SR 噬菌体，而 Br2 噬菌体的吸附则被很大程度地阻断。四种 S、T1 菌株（具有 O 和 T1 侧链）的噬菌体吸附表明，随着 O 侧链物质的增加，噬菌体的吸附减少，顺序如下：6SR、Br2 和 FO。P22 附着随着 O 侧链的增加而出现。与光滑亲本菌株相比，这些菌株的 LPS 组成中 O 特异性结构减少了 10 倍，而 T1 特异性物质的量与 T1 菌株相同。然而，SR、T1 菌株的短 O 侧链数量并没有减少，这表明 O 和 T1 侧链之间的明显竞争可能不是对 LPS 中可用位点的竞争。
