Detection of Pneumonia Associated Pathogens Using a Prototype Multiplexed Pneumonia Test in Hospitalized Patients with Severe Pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods – particularly in patients with prior antibiotic treatment – and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time.Trial RegistrationDeutsches Register Klinischer Studien (DRKS) DRKS00005684重症肺炎仍是引发发病与死亡的重要病因。聚合酶链式反应（Polymerase Chain Reaction, PCR）已被证实敏感性优于当前主流微生物检测方法——尤其在既往接受过抗生素治疗的患者中——因此可提升住院肺炎患者微生物学诊断的准确性。本研究为一项前瞻性多中心研究，招募成年住院患者并采集其呼吸道样本，针对14种典型细菌性肺炎相关病原体开展传统检测技术与多重PCR检测。研究招募周期为2012年3月至9月，共计纳入739份符合分析标准的新鲜原生样本，其中痰液样本75份、抽吸物样本421份、支气管灌洗液样本234份。通过微生物学方法共检出276株病原体，且均通过Curetis原型系统获得了有效PCR检测结果（阳性或阴性检测结果）。其中120株被该原型检测方法鉴定，另有50株未被检出。该原型检测系统的病原体鉴定总体性能为：灵敏度70.6%（95%置信区间（Confidence Interval, CI）下限：63.3%，上限：76.9%），特异度95.2%（95% CI下限：94.6%，上限：95.7%）。基于本研究结果，后续批量生产的设备临界值设置已完成优化调整。采用CE认证量产设备的调整后参数时，总体性能为：灵敏度78.7%（95% CI下限：72.1%），特异度96.6%（95% CI下限：96.1%）。原型检测的出结果时间中位数为5.2小时，而标准诊疗流程的检测耗时为43.5小时。本肺炎检测应用可实现肺炎致病病原体的快速、中等灵敏度检测，且所需手工操作时间极短。临床试验注册：德国临床研究注册库（Deutsches Register Klinischer Studien, DRKS）DRKS00005684