Clinical Pathology Department, Faculty of Medicine, Cairo University, Giza, Egypt.
Cardiology Department, Faculty of Medicine, Cairo University, Giza, Egypt.
Infection. 2015 Oct;43(5):523-9. doi: 10.1007/s15010-015-0761-2. Epub 2015 Mar 26.
Conventional diagnosis of infective endocarditis (IE) is based mainly on culture-dependent methods that may fail because of antibiotic therapy or fastidious microorganisms.
We aimed to evaluate the added values of serological and molecular methods for diagnosis of infective endocarditis.
One hundred and fifty-six cases of suspected endocarditis were enrolled in the study. For each patient, three sets of blood culture were withdrawn and serum sample was collected for Brucella, Bartonella and Coxiella burnetii antibody testing. Galactomannan antigen was added if fungal endocarditis was suspected. Broad range PCR targeting bacterial and fungal pathogens were done on blood culture bottles followed by sequencing. Culture and molecular studies were done on excised valve tissue when available.
One hundred and thirty-two cases were diagnosed as definite IE. Causative organisms were detected by blood cultures in 40 (30.3 %) of cases. Blood culture-negative endocarditis (BCNE) represented 69.7 %. Of these cases, PCR followed by sequencing on blood and valvular tissue could diagnose five cases of Aspergillus flavus. Eleven patients with BCNE (8.3 %) were diagnosed as zoonotic endocarditis by serology and PCR including five cases of Brucella spp, four cases of Bartonella spp and two cases of Coxiella burnetii. PCR detected three cases of Brucella spp and two cases of Bartonella spp, while cases of Coxiella burnetii were PCR negative. The results of all diagnostic tools decreased the percentage of non-identified cases of BCNE from 69.7 to 49.2 %.
Our data underline the role of serologic and molecular tools for the diagnosis of blood culture-negative endocarditis.
感染性心内膜炎（IE）的传统诊断主要基于依赖培养的方法，由于抗生素治疗或微生物的复杂性，这些方法可能会失败。
我们旨在评估血清学和分子方法对感染性心内膜炎诊断的附加价值。
本研究纳入了 156 例疑似心内膜炎患者。对每位患者采集三套血培养并收集血清样本，用于检测布鲁菌、巴尔通体和贝纳柯克斯体抗体。如果怀疑真菌性心内膜炎，则增加检测半乳甘露聚糖抗原。对血培养瓶进行针对细菌和真菌病原体的广谱 PCR，然后进行测序。如果有瓣膜组织，则进行培养和分子研究。
132 例被诊断为明确的 IE。40 例（30.3%）通过血培养检测到病原体。血培养阴性心内膜炎（BCNE）占 69.7%。在这些病例中，对血液和瓣膜组织进行 PCR 测序可诊断 5 例黄曲霉。11 例 BCNE（8.3%）患者通过血清学和 PCR 诊断为动物源性心内膜炎，包括 5 例布鲁菌属、4 例巴尔通体属和 2 例贝纳柯克斯体属。PCR 检测到 3 例布鲁菌属和 2 例巴尔通体属，而贝纳柯克斯体属则为 PCR 阴性。所有诊断工具的结果将 BCNE 的未识别病例百分比从 69.7%降低至 49.2%。
我们的数据强调了血清学和分子工具在诊断血培养阴性心内膜炎中的作用。
