Group B streptococcus (GBS) is an important pathogen causing neonatal early-onset disease. We evaluated the diagnostic performance of BD Max GBS assay (Becton Dickinson, Franklin Lakes, NJ, USA) without enrichment (direct BDM) for detecting GBS using vaginal and rectal specimens in comparison with culture. In total, 716 specimens collected from 358 pregnant women between June 2018 and May 2020 were included in this study. Bacterial culture was performed using ChromID Strep B agar (bioMérieux, Marcy-l'Étoile, France), and species identification results were confirmed using the VITEK-MS system (bioMérieux). The sensitivity of direct BDM for vaginal and rectal specimens was 75.0% and 100%, respectively. Thirteen specimens showed discrepant results: 10 false-negative results in the vaginal specimens and three false-positive results in the rectal specimens. The overall agreement between direct BDM and culture was 98.9% (354/358). The final sensitivity and specificity of direct BDM were 98.5% and 99.0%, respectively. Discrepant results-one false-negative and three false-positives-were obtained for four specimens. Direct BDM shows a good diagnostic performance and will be useful for GBS screening within a few hours.

中文翻译：

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BD MAX B 组链球菌 (GBS) 检测的性能，无需富集检测 GBS。

B族链球菌(GBS)是引起新生儿早发型疾病的重要病原体。我们评估了 BD Max GBS 测定法（Becton Dickinson，Franklin Lakes，NJ，USA）的诊断性能，与培养相比，使用阴道和直肠标本检测 GBS 时没有富集（直接 BDM）。本研究共纳入 2018 年 6 月至 2020 年 5 月期间从 358 名孕妇采集的 716 份标本。使用 ChromID Strep B 琼脂 (bioMérieux, Marcy-l'Étoile, France) 进行细菌培养，并使用 VITEK-MS 系统 (bioMérieux) 确认物种鉴定结果。直接 BDM 对阴道和直肠标本的敏感性分别为 75.0% 和 100%。十三个样本显示出不一致的结果：阴道标本有10个假阴性结果，直肠标本有3个假阳性结果。直接 BDM 和文化之间的总体一致性为 98.9% (354/358)。直接 BDM 的最终敏感性和特异性分别为 98.5% 和 99.0%。四个样本的结果不一致——一个假阴性和三个假阳性。直接 BDM 显示出良好的诊断性能，可在数小时内用于 GBS 筛查。