Campagnari A A, Karalus R, Apicella M, Melaugh W, Lesse A J, Gibson B W
Department of Medicine, State University of New York at Buffalo 14215.
Infect Immun. 1994 Jun;62(6):2379-86. doi: 10.1128/iai.62.6.2379-2386.1994.
Haemophilus ducreyi, a cause of genital ulcer disease in developing countries, appears to facilitate the heterosexual transmission of the human immunodeficiency virus in Africa. Despite an increase in studies of this gram-negative human pathogen, little is known about the pathogenesis of chancroid. Our studies have shown that the lipooligosaccharides (LOS) of H. ducreyi may play an important role in ulcer formation. Monoclonal antibody and mass spectrometric analyses identified a terminal trisaccharide present on H. ducreyi LOS that is immunochemically similar to human paragloboside. This epitope is present on the LOS of Neisseria gonorrhoeae, and it may be the site of attachment for pyocin lysis. We have used pyocin, produced by Pseudomonas aeruginosa, to select LOS variants with sequential saccharide deletions from N. gonorrhoeae. On the basis of the similarities between N. gonorrhoeae and H. ducreyi LOS, we employed the same technique to determine if H. ducreyi strains were susceptible to pyocin lysis. In this study, we report the generation of a pyocin N-resistant H. ducreyi strain which synthesizes a truncated version of the parental LOS. Further studies have shown that this H. ducreyi variant has lost the terminal LOS epitope defined by monoclonal antibody 3F11. This report demonstrates that H. ducreyi is sensitive to pyocins and that this technique can be used to generate H. ducreyi LOS variants. Such variants could be used in comparative studies to relate LOS structure to biologic function in the pathogenesis of chancroid.
杜克雷嗜血杆菌是发展中国家生殖器溃疡疾病的病因之一，在非洲似乎会促进人类免疫缺陷病毒的异性传播。尽管对这种革兰氏阴性人类病原体的研究有所增加，但对软下疳的发病机制仍知之甚少。我们的研究表明，杜克雷嗜血杆菌的脂寡糖（LOS）可能在溃疡形成中起重要作用。单克隆抗体和质谱分析确定了杜克雷嗜血杆菌LOS上存在的一种末端三糖，其免疫化学性质与人类副球蛋白相似。该表位存在于淋病奈瑟菌的LOS上，可能是绿脓菌素裂解的附着位点。我们利用铜绿假单胞菌产生的绿脓菌素，从淋病奈瑟菌中筛选出具有连续糖缺失的LOS变体。基于淋病奈瑟菌和杜克雷嗜血杆菌LOS之间的相似性，我们采用相同技术来确定杜克雷嗜血杆菌菌株是否易受绿脓菌素裂解。在本研究中，我们报告了一株对绿脓菌素N耐药的杜克雷嗜血杆菌菌株的产生，该菌株合成了亲本LOS的截短版本。进一步研究表明，该杜克雷嗜血杆菌变体已失去单克隆抗体3F11所定义的末端LOS表位。本报告表明杜克雷嗜血杆菌对绿脓菌素敏感，且该技术可用于产生杜克雷嗜血杆菌LOS变体。此类变体可用于比较研究，以将LOS结构与软下疳发病机制中的生物学功能联系起来。
