Bechah Yassina, Capo Christian, Mege Jean-Louis, Raoult Didier
Unité des Rickettsies, CNRS UMR 6020, Université de la Méditerranée, Faculté de Médecine, 27 Bld. Jean Moulin, 13385 Marseille Cedex 05, France.
Future Microbiol. 2008 Apr;3(2):223-36. doi: 10.2217/17460913.3.2.223.
Rickettsiae cause spotted fevers and typhus-related diseases in humans. Some of these diseases occur worldwide and are life-threatening, for example, epidemic typhus is still a major health problem despite the apparent efficiency of antibiotic treatment. In addition, Rickettsia prowazekii, the agent of epidemic typhus, and R. rickettsii, the agent of Rocky Mountain spotted fever, are microorganisms that could potentially be used as bioweapons to induce panic in the population. Rickettsiae are obligate intracellular bacteria in both vertebrate and invertebrate hosts, but rickettsial species differ in terms of association with arthropods, behavior of the vector to infection, pathophysiology and outcome of the disease. Understanding the pathogenic steps of rickettsioses is essential to develop protective strategies against these bacteriological threats. Unfortunately, the mechanisms involved in the pathogenesis of many rickettsioses are poorly characterized, and protective immunity is incompletely understood, in part because accurate animal models that mimic human diseases are lacking. In the past, murine models have been of limited value because infection of mice was without effect or resulted in erratic mortality. Recent studies have reported that rickettsial infection can be established in mice, depending on the genetic background of mice, the type of rickettsial species and the route of inoculation. These models may be useful for analyzing the pathogenesis of rickettsioses, especially epidemic typhus, evaluating new therapeutic molecules and vaccine candidates, and preventing future outbreaks.
立克次氏体可导致人类患斑点热和斑疹伤寒相关疾病。其中一些疾病在全球范围内发生且危及生命，例如，尽管抗生素治疗效果显著，但流行性斑疹伤寒仍是一个重大的健康问题。此外，流行性斑疹伤寒的病原体普氏立克次氏体和落基山斑点热的病原体立氏立克次氏体，是有可能被用作生物武器以引起民众恐慌的微生物。立克次氏体在脊椎动物和无脊椎动物宿主中均为专性细胞内细菌，但不同立克次氏体物种在与节肢动物的关联、载体对感染的行为、疾病的病理生理学和结果方面存在差异。了解立克次氏体病的致病步骤对于制定针对这些细菌学威胁的保护策略至关重要。不幸的是，许多立克次氏体病发病机制所涉及的机制尚未得到充分表征，保护性免疫也未被完全理解，部分原因是缺乏模拟人类疾病的精确动物模型。过去，小鼠模型的价值有限，因为小鼠感染后无效果或导致死亡率不稳定。最近的研究报告称，根据小鼠的遗传背景、立克次氏体物种类型和接种途径，立克次氏体感染可在小鼠中建立。这些模型可能有助于分析立克次氏体病的发病机制，尤其是流行性斑疹伤寒，评估新的治疗分子和候选疫苗，并预防未来的疫情爆发。
