Nikolaeva A I, Nastichkin I A, Romanova Iu M, Belova T S, Bondarenko V M, Kabanova E A, Kondrat'eva T K
Mol Gen Mikrobiol Virusol. 1990 Aug(8):15-8.
A nonvirulent strain of Shigella sonnei phase I has been obtained by integration of the transposon Tn5 into the invasiveness plasmid pSS120 in the virulent strain and designated NR18. The presence of the plasmid pSS120 in both strains results in the similar morphology and bacterial ability to agglutinate in the presence of antiserum to Shigella sonnei phase I antigen. The lipopolysaccharide preparations from the virulent and nonvirulent strains give the similar reactions with the antiserum in the reaction of hemagglutination. However, in the reaction of passive local hemolysis in the gel (Jerne reaction) the significant difference is revealed in the immunogenicity of the preparations, with the preparations from the virulent strain being 4-5 fold more immunogenic. In crossreaction, the antibodies secreted by the mouse spleen cells immunized by LPS from the virulent strain show a weak reaction with the ram erythrocytes sensitized by the LPS of the nonvirulent strain. Thus, the biological changes in the LPS of the nonvirulent strains that are, evidently, the consequence of the structural changes, are identified only by the most sensitive immunological techniques.
通过将转座子Tn5整合到有毒菌株的侵袭性质粒pSS120中，获得了宋内志贺氏菌I相的无毒菌株，并将其命名为NR18。两种菌株中均存在质粒pSS120，这导致它们在形态以及在存在针对宋内志贺氏菌I相抗原的抗血清时的细菌凝集能力方面相似。来自有毒和无毒菌株的脂多糖制剂在血凝反应中与抗血清产生相似的反应。然而，在凝胶中的被动局部溶血反应（耶尔恩反应）中，制剂的免疫原性存在显著差异，有毒菌株的制剂免疫原性高4至5倍。在交叉反应中，用有毒菌株的脂多糖免疫的小鼠脾细胞分泌的抗体与用无毒菌株的脂多糖致敏的公羊红细胞反应较弱。因此，无毒菌株脂多糖的生物学变化显然是结构变化的结果，只有通过最敏感的免疫学技术才能识别。
