Winn W C, Myerowitz R L
Hum Pathol. 1981 May;12(5):401-22. doi: 10.1016/s0046-8177(81)80021-4.
Following the discovery of Legionella pneumophila as the cause of an epidemic of pneumonia at an American Legion convention in Philadelphia, a group of related bacteria were recognized as additional human pathogens. This newly established bacterial genus, Legionella, includes the agents of Legionnaires' disease, Pittsburgh pneumonia, and several related infections. There are many similarities in the pathology of human infection caused by all the Legionella species. All produce a severe confluent lobular or lobar pneumonia, and abscess formation is not uncommon. A leukocytoclastic inflammatory infiltrate of neutrophils and macrophages, "septic" vasculitis of small blood vessels, coagulation necrosis, and focal septal disruption are characteristic but not diagnostic features. The inflammatory response is clearly that of a bacterial pneumonia with a necrotizing component, and does not resemble most mycoplasmal, chlamydial, or viral pneumonias. The bacteria can be demonstrated well by special stains. Acid fastness of Legionella micdadei, the cause of Pittsburgh pneumonia, is a helpful presumptive clue to diagnosis. The bacteria can be presumptively speciated in tissue by direct immunofluorescence. In addition, reliable recovery of the organisms on agar media now allows a specific diagnosis to be made. As a group, these infections are properly referred to as the Legionella pneumonias.
在费城美国退伍军人协会大会上发现嗜肺军团菌是肺炎流行的病因之后，一组相关细菌被确认为另外的人类病原体。这个新建立的细菌属——军团菌属，包括军团病、匹兹堡肺炎及几种相关感染的病原体。所有军团菌属物种引起的人类感染在病理学上有许多相似之处。所有感染都会导致严重的融合性小叶或大叶性肺炎，脓肿形成也并不罕见。中性粒细胞和巨噬细胞的白细胞破碎性炎性浸润、小血管的“败血性”血管炎、凝固性坏死以及局灶性间隔破坏是其特征性表现，但并非诊断性特征。这种炎症反应显然是伴有坏死成分的细菌性肺炎的反应，与大多数支原体、衣原体或病毒性肺炎不同。通过特殊染色可以很好地显示这些细菌。匹兹堡肺炎的病原体米克戴德军团菌的抗酸性是有助于诊断的一个推测线索。通过直接免疫荧光法可以在组织中初步鉴定这些细菌。此外，现在能够在琼脂培养基上可靠地培养出这些微生物，从而可以做出明确诊断。作为一组感染，这些感染被恰当地称为军团菌肺炎。
