Point of Care Nucleic Acid Diagnostic Device for Quantifying Bacteremia

描述（由申请人提供）：只有34%的严重脓毒症病例血培养呈阳性，抗生素的选择通常基于患者的临床病史。在危及生命的病例中，在获得培养结果之前就开始使用广谱抗生素治疗，因为在最初48小时内开始治疗可以显著降低死亡率。IQuum开发了一种试管实验室（Liat(tm)）分析仪，可用于在急诊科患者就诊后1小时内检测血流感染。该技术使最低限度训练的医疗从业人员能够使用全血作为样本输入执行核酸测试。我们建议建立一种检测16S核糖体RNA的逆转录聚合酶链反应（RT-PCR）诊断方法。由于RT-PCR检测中每个细胞含有1000到10000个rRNA拷贝，因此该装置的预期灵敏度将允许检测到~3个细胞/10毫升全血的菌血症滴度。我们建议使用BUGS'n BEADS(tm) （Genpoint AS）或凝集素包被过滤器进行样品制备；一种基于细菌对具有高亲和力的固相基质的初始吸附的方法。另外，我们将探索细菌rRNA的核酸特异性捕获。所有这些样品制备替代方案将使用相同的诊断设备进行测试。我们进一步建议获得FDA对多重检测的批准，并为该设备寻求CLIA豁免状态。我们建议提交初始510(k)，重点关注最常见的败血症原因：大肠杆菌和葡萄球菌sp（均为凝固阴性菌和金黄色葡萄球菌），它们占血流感染的60%左右。一旦器械获得该有限使用适应症的510(k)批准，我们建议提交简化的510(k)，用于在临床试验期间获得额外数据时检测额外的细菌（列在工作计划主体中）。

DESCRIPTION (provided by applicant): Positive blood culture results are available in only 34% of such severe sepsis cases and antibiotic selection is usually based on the patient's clinical history. In life threatening cases, treatment is initiated with broad spectrum antibiotics before culture results are obtained because initiating treatment in the first 48 hours can significantly lower mortality rates. IQuum has developed a lab-in-a-tube (Liat(tm)) Analyzer which can be used to detect blood stream infections within 1 hour of patient presentation at an emergency department. This technology enables minimally trained healthcare practitioners to perform a nucleic acid test using whole blood as the sample input. We propose to develop a reverse transcriptase polymerase chain reaction (RT-PCR) diagnostic assay for detecting the 16S ribosomal RNA. Because each cell contains 1,000 to 10,000 copies of rRNA the RT-PCR assay, the expected sensitivity of the device will allow for the detection of bacteremia titers of ~3 cells /10 ml of whole blood. We propose to use BUGS'n BEADS(tm) (Genpoint AS) or lectin coated filters for sample preparation; a method based on an initial adsorption of bacteria to a solid phase matrix with high affinity for bacteria. Alternatively, we will explore nucleic acid specific capture of bacterial rRNA. All of these sample preparation alternatives will be tested using the same diagnostic device. We further propose to obtain FDA approval for a multiplex assay as well as seek CLIA waived status for the device. We propose to file our initial 510(k) focusing on the most common causes of sepsis: Escherichia coli and Staphylococcus sp (both coagulate negative species and S. aureus), which account for ~60% of blood stream infections. Once the device has obtained 510(k) approval for this limited indication of use, we propose to file abbreviated 510(k) for the detection of additional bacteria (listed in the body of the Work Plan) as additional data is acquired during the clinical trial.