Lück P C, Steinert M
Institut für Medizinische Mikrobiologie, Nationales Konsiliarlabor für Legionellen, TU-Dresden, Fiedlerstrasse 42, 01307 Dresden.
Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2006 May;49(5):439-49. doi: 10.1007/s00103-006-1254-3.
Legionella species are ubiquitous in aquatic environments. About 50 years ago they entered the engineered (technical) environment, i.e. warm water systems with zones of stagnation. Since that time they represent a hygienic problem. After transmission to humans via aerosols legionellae might cause Legionella pneumonia (legionnaires' disease) or influenza-like respiratory infections (Pontiac fever). Epidemiological data suggest that Legionella strains might differ substantially in their virulence properties. Although the molecular basis is not understood L. pneumophila serogroup 1 especially MAb 3/1-positive strains cause the majority of infections. The main virulence feature is the ability to multiply intracellularly. After uptake into macrophages legionellae multiply in a specialized vacuole and finally lyse their host cells. Several bacterial factors like surface components, secretion systems and iron uptake systems are involved in this process. Since the clinical picture of Legionella pneumonia does not allow differentiation from pneumoniae caused by other pathogens, microbiological diagnostic methods are needed to establish the diagnosis. Cultivation of legionellae from clinical specimens, detection of antigens and DNA in patients' samples and detection of antibodies in serum samples are suitable methods. However, none of the diagnostic tests presently available offers the desired quality with respect to sensitivity and specificity. Therefore, the standard technique is to use several diagnostic tests in parallel. Advantages and disadvantages of the diagnostic procedures are discussed. Therapeutic options for Legionella infections are newer macrolides like azithromycin and chinolones (ciprofloxacin, levofloxacin and moxifloxacin).
军团菌属在水生环境中普遍存在。大约50年前，它们进入了工程（技术）环境，即存在停滞区域的温水系统。从那时起，它们就成了一个卫生问题。通过气溶胶传播给人类后，军团菌可能会引发军团菌肺炎（军团病）或类似流感的呼吸道感染（庞蒂亚克热）。流行病学数据表明，军团菌菌株的毒力特性可能有很大差异。尽管分子基础尚不清楚，但嗜肺军团菌血清型1，尤其是单克隆抗体3/1阳性菌株导致了大多数感染。主要的毒力特征是在细胞内繁殖的能力。被巨噬细胞摄取后，军团菌在一个特殊的液泡中繁殖，最终裂解其宿主细胞。几个细菌因子，如表面成分、分泌系统和铁摄取系统都参与了这个过程。由于军团菌肺炎的临床表现无法与其他病原体引起的肺炎相区分，因此需要微生物学诊断方法来确立诊断。从临床标本中培养军团菌、检测患者样本中的抗原和DNA以及检测血清样本中的抗体都是合适的方法。然而，目前可用的诊断测试在敏感性和特异性方面都没有达到理想的质量。因此，标准技术是同时使用几种诊断测试。文中讨论了诊断程序的优缺点。军团菌感染的治疗选择是新型大环内酯类药物，如阿奇霉素和喹诺酮类药物（环丙沙星、左氧氟沙星和莫西沙星）。
