Department of Pathology, Rhode Island Hospital, Providence, Rhode Island, USA.
The Warren Alpert Medical School of Brown Universitygrid.40263.33, Providence, Rhode Island, USA.
Microbiol Spectr. 2022 Oct 26;10(5):e0179622. doi: 10.1128/spectrum.01796-22. Epub 2022 Sep 7.
Rapid identification of pathogens is critical in bloodstream infections. We evaluated the diagnostic performance of the GenMark Dx ePlex blood culture identification (BCID) panels and the adoption of the ePlex system into the clinical laboratory workflow. Nonduplicate remnant specimens of positive blood cultures were prospectively tested using ePlex panels between January and March 2020. A total of 313 unique positive blood culture specimens were tested. The identified organisms consisted of 98 Gram-negative rods (GNR), 90 Gram-positive cocci (GPC) in clusters, 62 GPC in chains, 21 Gram-positive rods, and 20 yeasts; 22 organisms were off panel. The positive percent agreement was 100% across all organisms tested after discordancy resolution, while the negative percent agreement was 100% across all targets except Corynebacterium spp., where it was 99.7%. The ePlex BCID panels accurately detected 5 pan targets and 42 antimicrobial resistance gene markers, including 31 , 4 , 6 CTX-M, and 1 KPC gene. The median times to result were calculated as 2.5 h for Xpert MRSA/SA in GPC in clusters, 9.5 h for Accelerate Pheno (identification and susceptibility) in GNR, 6 h for peptide nucleic acid fluorescent hybridization [PNA-FISH] in yeasts, 27 h for the latex agglutination test in S. aureus, 29 h for Lancefield serotyping in GPC in chains, and 29 h for Vitek-MS in GNR. In our laboratory, the ePlex panels could substantially reduce the time to result for bloodstream infection (BSI) caused by Streptococcus spp., Enterococcus spp., and Candida spp. The highly accurate ePlex panels can help streamline laboratory efficiency in the blood bench workflow, reducing the time to result for identification of BSI pathogens. Sepsis is a leading cause of morbidity and mortality worldwide. Rapid identification of the causative agent is of critical importance for the prompt initiation of the appropriate antibiotic treatment. In this study, we evaluated the diagnostic performance of the GenMark Dx ePlex blood culture identification (BCID) panels and their adoption into the clinical laboratory workflow. We prospectively tested 313 blood culture isolates and found that ePlex BCID panels had a positive percent agreement of 100% across all organisms tested after discordancy resolution. The negative percent agreement was 100% across all targets except Corynebacterium spp., where it was 99.7%. This new rapid technology (turnaround time of ~90 min) can help streamline laboratory efficiency in the blood bench workflow, reducing the time to result for identification of BSI pathogens. Adoption should be individualized based on the needs of the patient population and capabilities of the laboratory.
快速鉴定血流感染中的病原体至关重要。我们评估了 GenMark Dx ePlex 血培养鉴定（BCID）板的诊断性能，以及将 ePlex 系统引入临床实验室工作流程的情况。2020 年 1 月至 3 月，前瞻性地使用 ePlex 板检测了非重复的阳性血培养剩余标本。共检测了 313 个独特的阳性血培养标本。鉴定出的生物体包括 98 个革兰氏阴性杆菌（GNR）、90 个革兰氏阳性球菌（GPC）簇、62 个 GPC 链、21 个革兰氏阳性杆菌和 20 个酵母；22 个生物体不在板上。经过不一致性解决后，所有测试生物体的阳性符合率均为 100%，而所有靶标（除棒状杆菌属外）的阴性符合率均为 100%，棒状杆菌属的阴性符合率为 99.7%。ePlex BCID 板准确地检测到 5 个 pan 靶标和 42 个抗菌药物耐药基因标记物，包括 31 个 CTX-M 和 1 个 KPC 基因。结果的中位时间计算为：Xpert MRSA/SA 在 GPC 簇中的时间为 2.5 小时，Accelerate Pheno（鉴定和药敏）在 GNR 中的时间为 9.5 小时，肽核酸荧光杂交[PNA-FISH]在酵母中的时间为 6 小时，乳胶凝集试验在金黄色葡萄球菌中的时间为 27 小时，Lancefield 血清分型在 GPC 链中的时间为 29 小时，Vitek-MS 在 GNR 中的时间为 29 小时。在我们的实验室中，ePlex 板可以显著缩短由链球菌属、肠球菌属和假丝酵母菌属引起的血流感染（BSI）的结果时间。高度准确的 ePlex 板有助于简化血液工作台工作流程中的实验室效率，减少鉴定 BSI 病原体的结果时间。败血症是全球发病率和死亡率的主要原因。快速鉴定病原体对于及时启动适当的抗生素治疗至关重要。在这项研究中，我们评估了 GenMark Dx ePlex 血培养鉴定（BCID）板的诊断性能及其在临床实验室工作流程中的应用。我们前瞻性地检测了 313 个血培养分离株，发现 ePlex BCID 板在解决不一致性后，所有测试生物体的阳性符合率均为 100%。除棒状杆菌属外，所有靶标的阴性符合率均为 100%，棒状杆菌属的阴性符合率为 99.7%。这种新的快速技术（~90 分钟的周转时间）可以帮助简化血液工作台工作流程中的实验室效率，减少鉴定 BSI 病原体的结果时间。应根据患者人群的需求和实验室的能力个体化采用。
