Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, California, USA.
Department of Pediatrics, Division of Infectious Diseases, Children's Hospital Los Angeles, Los Angeles, California, USA.
J Clin Microbiol. 2022 Aug 17;60(8):e0012222. doi: 10.1128/jcm.00122-22. Epub 2022 Jul 19.
Bloodstream infection poses a significant medical emergency that necessitates timely administration of appropriate antibiotics. Standard laboratory workup for antimicrobial susceptibility testing (AST) involves subculture of organisms from positive blood bottles followed by testing using broth microdilution; however, this process can take several days. The Accelerate Pheno Blood Culture panel (Pheno) provides rapid phenotypic testing of selected Gram-negative organisms directly from positive blood cultures. This has the potential to shorten the AST process to several hours and impact time to antimicrobial optimization and subsequent clinical outcomes; however, these metrics have not been assessed in pediatric populations. We retrospectively compared two patient cohorts with blood cultures positive for on-panel Gram-negative organisms: 82 cases tested by conventional AST methods, and 80 cases postintervention at our pediatric hospital. Susceptibility testing from the Pheno yielded 91.5% categorical agreement with a broth microdilution-based reference method with 7.4% minor error, 1.1% major error, and 0.1% very major error rates. The median time from blood culture positivity to AST decreased from 20.0 h to 9.7 h ( < 0.001), leading to an overall decrease in time from blood culture positivity to change in therapy from 36.0 h to 25.0 h ( < 0.001). There was no observed change in length of stay or 30-day mortality. Median duration on meropenem decreased from 64.8 h to 31.6 h ( = 0.04). We conclude the Pheno had accurate performance and that implementation allowed for faster AST reporting, improved time to optimal therapy, and decreased duration on meropenem in children.
血流感染是一种重大的医疗紧急情况，需要及时给予适当的抗生素治疗。进行抗菌药物敏感性试验（AST）的标准实验室检测包括从阳性血培养瓶中分离出生物体，然后进行肉汤微量稀释检测；然而，这个过程可能需要几天时间。Accelerate Pheno 血培养板（Pheno）可直接从阳性血培养物中快速检测选定的革兰氏阴性生物体的表型。这有可能将 AST 过程缩短至数小时，并影响抗菌药物优化和随后的临床结果的时间；然而，这些指标尚未在儿科人群中进行评估。我们回顾性比较了两组血培养阳性的革兰氏阴性菌患者：82 例采用传统 AST 方法检测，80 例在我院儿科进行干预后检测。Pheno 的药敏试验与基于肉汤微量稀释的参考方法具有 91.5%的分类一致性，Minor 错误率为 7.4%，Major 错误率为 1.1%，Very Major 错误率为 0.1%。从血培养阳性到 AST 的中位时间从 20.0 小时缩短至 9.7 小时（ < 0.001），从而使从血培养阳性到治疗改变的总时间从 36.0 小时缩短至 25.0 小时（ < 0.001）。住院时间或 30 天死亡率没有观察到变化。美罗培南的中位使用时间从 64.8 小时缩短至 31.6 小时（ = 0.04）。我们得出结论，Pheno 具有准确的性能，实施后可以更快地报告 AST，改善最佳治疗时机，并减少儿童使用美罗培南的时间。
