采用自动化 PCR 检测方法，即 GenomEra S. pneumoniae，用于快速检测血培养中的肺炎链球菌。

Use of an automated PCR assay, the GenomEra S. pneumoniae, for rapid detection of Streptococcus pneumoniae in blood cultures.

机构信息

From the Fimlab Laboratories , Tampere , Finland.

出版信息

Infect Dis (Lond). 2015;47(11):796-800. doi: 10.3109/23744235.2015.1063157. Epub 2015 Jul 10.

DOI:10.3109/23744235.2015.1063157

PMID:26162002

Abstract

BACKGROUND

Streptococcus pneumoniae is recognized as a major cause of pneumonia, meningitis, and bacteremia. Since the mortality rate for pneumococcal bacteremia remains high, the reliable detection of the bacterium in blood samples is important. In this study, the performance of a new automated PCR assay, the GenomEra(™) S. pneumoniae, for direct detection of S. pneumoniae in blood cultures was investigated.

METHODS

In total, 200 samples were analyzed, including 90 previously identified culture collection isolates and 110 blood culture specimens. The species identification was confirmed with routine diagnostic methods including MALDI-TOF or 16S rDNA sequencing.

RESULTS

From culture collection, the GenomEra S. pneumoniae assay correctly identified all 37 S. pneumoniae isolates consisting of 18 different serotypes, while all 53 non-S. pneumoniae isolates yielded negative test results. Of 110 blood culture specimens, 46 grew S. pneumoniae and all were positive by the GenomEra assay direct from bottle. The detection sensitivity and specificity of the GenomEra assay for direct analysis of S. pneumoniae in signal positive blood culture bottles was 100%, respectively. With a straightforward sample preparation protocol of blood cultures the results were available within 55 min, thus being significantly quicker than by the routinely used identification methods (18-48 h). The two-step, time-resolved fluorometric measurement mode employed by the GenomEra CDX(™) instrument showed no interference from blood or charcoal.

CONCLUSION

The GenomEra S. pneumoniae assay is a tool that performs well for the rapid and reliable detection of S. pneumoniae in blood cultures.

摘要

背景

肺炎链球菌被认为是肺炎、脑膜炎和菌血症的主要病因。由于肺炎球菌菌血症的死亡率仍然很高，因此可靠地检测血液样本中的细菌非常重要。在这项研究中，研究了一种新的自动化 PCR 检测方法——GenomEra(™) S. pneumoniae，用于直接检测血培养物中的肺炎链球菌。

方法

总共分析了 200 个样本，包括 90 个先前鉴定的培养物分离株和 110 个血培养标本。通过包括 MALDI-TOF 或 16S rDNA 测序在内的常规诊断方法确认了物种鉴定。

结果

从培养物中，GenomEra S. pneumoniae 检测方法正确鉴定了由 18 种不同血清型组成的 37 株肺炎链球菌分离株，而所有 53 株非肺炎链球菌分离株的检测结果均为阴性。在 110 个血培养标本中，46 个培养出肺炎链球菌，所有标本均直接从瓶中通过 GenomEra 检测呈阳性。GenomEra 检测方法对信号阳性血培养瓶中肺炎链球菌的直接分析的检测灵敏度和特异性分别为 100%。采用简单的血培养物样品制备方案，结果可在 55 分钟内获得，明显快于常规使用的鉴定方法（18-48 小时）。GenomEra CDX(™) 仪器采用的两步、时间分辨荧光测量模式不会受到血液或木炭的干扰。