Gazzano Vincent, Berger Anne, Benito Yvonne, Freydiere Anne-Marie, Tristan Anne, Boisset Sandrine, Carricajo Anne, Poyart Claire, Vandenesch François, Descours Ghislaine
Hospices Civils de Lyon, Laboratoire de Bactériologie, Centre de Biologie et de Pathologie Est, Bron, France.
Laboratoire de Bactériologie, CHU de Saint-Etienne, Saint-Etienne, France.
J Clin Microbiol. 2016 Apr;54(4):994-9. doi: 10.1128/JCM.02516-15. Epub 2016 Jan 27.
Rapid antigen detection tests (RADTs) for group A streptococci (GAS) are widely used for diagnosing acute pharyngitis, which has led to a considerable reduction in antibiotic prescriptions over the past decade. Beyond this intended use, their reassessment on invasive samples may be relevant in the management of life-threatening GAS infections. To this end, we evaluated the performances of three RADTs, culture, GAS PCR, and 16S rRNA gene PCR assays, and compared them with a composite gold standard (GAS-PCR assay and/or culture) for the diagnosis of severe GAS infection. A total of 192 specimens from deep-tissue (mostly normally sterile) sites enriched for 75 GAS-positive samples were enrolled in the study. The three evaluated RADTs showed sensitivities ranging from 88.0% to 94.7% versus 98.7% for GAS PCR, 84% for 16S rRNA gene PCR, and 77.3% for culture. The sensitivities of the ImmunoCardSTAT! Strep A test (Meridian Bioscience) and the NADAL Strep A strip (Nal Von Minden) were similar to that of GAS PCR (P= 0.25 and 0.03, respectively) and higher than that of culture (P= 0.001 and 0.006, respectively), whereas the SD Bioline Strep A test strip (Standard Diagnostics) showed a performance similar to that of culture (P= 0.02). The three RADTs detected 10 distinctemmtypes, including a predominance ofemm1 (33.3%),emm89 (10.6%), andemm12 (7.6%). No false-positive results were observed, leading to a specificity of 100% for all the evaluated RADTs. The GAS RADTs turned out to be sensitive, specific, and easy-to-use tools that may aid in the management of invasive GAS infections in 24/7 point-of-care laboratories by enabling early diagnosis and focused therapy.
用于A组链球菌（GAS）的快速抗原检测试验（RADT）被广泛用于诊断急性咽炎，这使得过去十年抗生素处方量大幅减少。除了这一预期用途外，对侵入性样本进行重新评估可能对危及生命的GAS感染的管理具有重要意义。为此，我们评估了三种RADT、培养、GAS PCR和16S rRNA基因PCR检测方法的性能，并将它们与用于诊断严重GAS感染的综合金标准（GAS-PCR检测和/或培养）进行比较。该研究共纳入了192份来自深部组织（大多为正常无菌）部位的标本，其中75份为GAS阳性样本。三种评估的RADT的敏感性范围为88.0%至94.7%，而GAS PCR为98.7%，16S rRNA基因PCR为84%，培养为77.3%。ImmunoCardSTAT! A群链球菌检测试剂（Meridian Bioscience公司）和NADAL A群链球菌检测试纸（Nal Von Minden公司）的敏感性与GAS PCR相似（P值分别为0.25和0.03），且高于培养法（P值分别为0.001和0.006），而SD Bioline A群链球菌检测试纸（Standard Diagnostics公司）的性能与培养法相似（P = 0.02）。三种RADT检测到10种不同的emm型，其中以emm1（33.3%）、emm89（10.6%）和emm12（7.6%）为主。未观察到假阳性结果，所有评估的RADT的特异性均为100%。结果表明，GAS RADT是敏感、特异且易于使用的工具，通过实现早期诊断和针对性治疗，可有助于在全天候即时检验实验室中管理侵入性GAS感染。
