Ensgraber M, Loos M
Institute of Medical Microbiology, Johannes Gutenberg-University, Mainz, Federal Republic of Germany.
Infect Immun. 1992 Aug;60(8):3072-8. doi: 10.1128/iai.60.8.3072-3078.1992.
Salmonella typhimurium infections have increased during the last few years. However, the interplay of virulence factors in S. typhimurium pathogenesis is still poorly understood, particularly with regard to the mechanisms and components of the bacterium which are involved in its interaction with the intestinal mucus. We have observed that S. typhimurium is aggregated by incubation with colonic mucus (guinea pig model). To quantify this phenomenon, an aggregation assay was established. By using this assay, it was found that the aggregation profile of S. typhimurium strains freshly isolated from patients (age 9 and older) with salmonellosis correlated with the severity of the disease. An isolate with high aggregation behavior was chosen for characterization of the bacterial component involved in binding to colonic mucus material. The component of S. typhimurium responsible for aggregation was purified and characterized as a 66-kDa protein which was able to completely inhibit mucus-mediated bacterial aggregation. This protein was recognized by monoclonal antibodies against the 65-kDa heat shock protein (HSP) of Mycobacterium leprae. The 66-kDa protein of S. typhimurium was inducible by incubating the bacteria at 50 degrees C and was secreted into the supernatant, from which it could be isolated in both dimeric and polymeric forms. The monoclonal anti-HSP 65, as well as a polyclonal antibody against the 66-kDa protein of S. typhimurium, caused dose-dependent inhibition of the aggregation of S. typhimurium by crude mucus preparations. This is the first report showing that a bacterial HSP is involved in mucus-mediated interaction of pathogens with the host.
在过去几年中，鼠伤寒沙门氏菌感染有所增加。然而，对于鼠伤寒沙门氏菌致病过程中毒力因子之间的相互作用仍知之甚少，特别是关于该细菌与肠道黏液相互作用所涉及的机制和成分。我们观察到，将鼠伤寒沙门氏菌与结肠黏液（豚鼠模型）一起孵育时会发生聚集。为了量化这一现象，建立了一种聚集测定法。通过使用该测定法发现，从9岁及以上的沙门氏菌病患者中新鲜分离出的鼠伤寒沙门氏菌菌株的聚集情况与疾病的严重程度相关。选择具有高聚集行为的分离株来表征参与结合结肠黏液物质的细菌成分。负责聚集的鼠伤寒沙门氏菌成分被纯化，并鉴定为一种66 kDa的蛋白质，它能够完全抑制黏液介导的细菌聚集。这种蛋白质可被抗麻风分枝杆菌65 kDa热休克蛋白（HSP）的单克隆抗体识别。鼠伤寒沙门氏菌的66 kDa蛋白质在50℃孵育细菌时可被诱导，并分泌到上清液中，可从其中以二聚体和多聚体形式分离出来。抗HSP 65单克隆抗体以及抗鼠伤寒沙门氏菌66 kDa蛋白质的多克隆抗体对粗制黏液制剂诱导的鼠伤寒沙门氏菌聚集具有剂量依赖性抑制作用。这是首次报道表明细菌热休克蛋白参与病原体与宿主的黏液介导的相互作用。
