Richard-Greenblatt Melissa, Rutherford Candy, Luinstra Kathy, Cárdenas Ana María, Pang Xiaoli Lilly, Jayaratne Padman, Smieja Marek
Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
Hamilton Regional Laboratory Medicine Program, St. Joseph's Healthcare, Hamilton, Ontario, Canada.
J Clin Microbiol. 2020 Aug 24;58(9). doi: 10.1128/JCM.00178-20.
The FecalSwab system (Copan Italia, Brescia, Italy) is a convenient alternative to bulk stool for the diagnosis of enteric pathogens. Although the U.S. Food and Drug Administration (FDA) approved for transport and culture of enteric bacterial pathogens, the FecalSwab has not been well assessed for its suitability with molecular platforms. In this study, we evaluated the FecalSwab as a specimen type for the BD Max system using the viral and bacterial enteric panels (BD Diagnostics, Baltimore, MD, USA). A total of 186 unpreserved stool specimens were collected and used to prepare matched bulk stool and FecalSwab samples. Performance was equivalent ( > 0.48) to bulk stool for all targets when 50 μl of FecalSwab specimen was loaded onto the BD Max assays. As stool specimens are often collected off-site from the clinical microbiology laboratory and require transport, we assessed the stability of stool specimens stored for up to 14 days at 4°C, 22°C, or 35°C to account for varying transportation conditions. Molecular detection for the majority of viral targets (excluding astrovirus) was unaffected (change in cycle threshold [Δ ] ≤ 1) by sample storage temperature over the 2-week period; however, detection of enteric bacteria was variable if specimens were not refrigerated (22°C or 35°C). By demonstrating equivalent performance to matched bulk stool and maintaining molecular detection sensitivity when stored at 4°C, we suggest that the FecalSwab is a suitable specimen type for enteropathogen diagnostics on the BD Max system.
粪便拭子系统（意大利科潘公司，意大利布雷西亚）是一种用于诊断肠道病原体的便捷替代方法，可替代大量粪便样本。尽管美国食品药品监督管理局（FDA）已批准其用于肠道细菌病原体的运输和培养，但粪便拭子在分子检测平台上的适用性尚未得到充分评估。在本研究中，我们使用病毒和细菌肠道检测板（美国BD诊断公司，马里兰州巴尔的摩）评估了粪便拭子作为BD Max系统的样本类型。共收集了186份未保存的粪便样本，并用于制备匹配的大量粪便样本和粪便拭子样本。当将50μl粪便拭子样本加载到BD Max检测中时，所有检测目标的性能与大量粪便样本相当（>0.48）。由于粪便样本通常在临床微生物实验室外采集且需要运输，我们评估了粪便样本在4°C、22°C或35°C下保存长达14天的稳定性，以考虑不同的运输条件。在两周时间内，大多数病毒检测目标（不包括星状病毒）的分子检测不受样本储存温度的影响（循环阈值变化[Δ]≤1）；然而，如果样本未冷藏（22°C或35°C），肠道细菌的检测结果则会有所不同。通过证明与匹配的大量粪便样本具有等效性能，并在4°C储存时保持分子检测灵敏度，我们认为粪便拭子是BD Max系统上用于肠道病原体诊断的合适样本类型。
