Brouqui P, Raoult D
Unité des Rickettsies, CNRS UPRESA 6020, Faculté de Médecine, 13385 Marseille Cedex 5, France.
Clin Microbiol Rev. 2001 Jan;14(1):177-207. doi: 10.1128/CMR.14.1.177-207.2001.
The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation.
在存在革兰氏阳性球菌持续菌血症的情况下，感染性心内膜炎的病因诊断很容易做出。然而，血培养可能含有一种很少与心内膜炎相关的细菌，如乳酸杆菌属、克雷伯菌属、非产毒性棒状杆菌、沙门氏菌、孪生球菌属、弯曲杆菌属、气单胞菌属、耶尔森菌属、诺卡菌属、巴斯德菌属、李斯特菌属或红斑丹毒丝菌属，这需要进一步调查以确定其与心内膜炎的关系，或者尽管临床评估支持，但血培养可能无诊断价值。在后一种情况下，病原体要么是苛求的细胞外细菌，要么是细胞内细菌。苛求的细胞外细菌，如营养缺陷菌、HACEK菌群细菌、梭菌属、布鲁菌属、军团菌属、分枝杆菌属和巴尔通体属，需要补充培养基、延长培养时间和特殊培养条件。细胞内细菌，如伯氏考克斯体，通常无法分离。培养阴性的心内膜炎最常见的两种病原体是伯氏考克斯体和巴尔通体属。它们的诊断通常通过血清学方法进行。对切除的心脏瓣膜进行包括过碘酸-希夫（PAS）染色和分子方法在内的系统性病理检查，已能够识别惠普尔杆菌性心内膜炎。当通过常规实验室评估无法明确病因诊断时，应系统地对瓣膜进行特殊染色（如沃辛-斯塔里染色、吉姆尼兹染色和PAS染色）和广谱聚合酶链反应的病理检查。
