Centre de recherche du CHU de Québec, Centre de recherche en infectiologie de l'Université Laval (CRI), Quebec, Canada;
Clin Chem. 2014 Apr;60(4):660-6. doi: 10.1373/clinchem.2013.213504. Epub 2014 Jan 24.
Group B streptococcal infections are the leading cause of sepsis and meningitis in newborns. A rapid and reliable method for the detection of this pathogen at the time of delivery is needed for the early treatment of neonates. Isothermal amplification techniques such as recombinase polymerase amplification have advantages relative to PCR in terms of the speed of reaction and simplicity.
We studied the clinical performance of recombinase polymerase amplification for the screening of group B streptococci in vaginal/anal samples from 50 pregnant women. We also compared the limit of detection and the analytical specificity of this isothermal assay to real-time PCR (RT-PCR).
Compared to RT-PCR, the recombinase polymerase amplification assay showed a clinical sensitivity of 96% and a clinical specificity of 100%. The limit of detection was 98 genome copies and the analytical specificity was 100% for a panel of 15 bacterial and/or fungal strains naturally found in the vaginal/anal flora. Time-to-result for the recombinase polymerase amplification assay was <20 min compared to 45 min for the RT-PCR assay; a positive sample could be detected as early as 8 min.
We demonstrate the potential of isothermal recombinase polymerase amplification assay as a clinically useful molecular diagnostic tool that is simple and faster than PCR/RT-PCR. Recombinase polymerase amplification offers great potential for nucleic acid-based diagnostics at the point of care.
B 群链球菌感染是新生儿败血症和脑膜炎的主要原因。需要一种快速可靠的方法，在分娩时检测这种病原体，以便对新生儿进行早期治疗。与 PCR 相比，等温扩增技术（如重组酶聚合酶扩增）在反应速度和简便性方面具有优势。
我们研究了重组酶聚合酶扩增法在 50 名孕妇的阴道/肛门样本中筛查 B 群链球菌的临床性能。我们还比较了这种等温检测与实时 PCR（RT-PCR）的检测限和分析特异性。
与 RT-PCR 相比，重组酶聚合酶扩增法的临床灵敏度为 96%，临床特异性为 100%。检测限为 98 个基因组拷贝，对一组 15 种自然存在于阴道/肛门菌群中的细菌和/或真菌菌株的分析特异性为 100%。与 RT-PCR 检测 45 分钟相比，重组酶聚合酶扩增检测的结果时间<20 分钟；阳性样本最早可在 8 分钟内检出。
我们证明了等温重组酶聚合酶扩增检测作为一种简单、比 PCR/RT-PCR 更快的临床有用的分子诊断工具的潜力。重组酶聚合酶扩增为即时护理点的核酸诊断提供了巨大的潜力。
