Marschal Matthias, Bachmaier Johanna, Autenrieth Ingo, Oberhettinger Philipp, Willmann Matthias, Peter Silke
Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany.
German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany.
J Clin Microbiol. 2017 Jul;55(7):2116-2126. doi: 10.1128/JCM.00181-17. Epub 2017 Apr 26.
Bloodstream infections (BSI) are an important cause of morbidity and mortality. Increasing rates of antimicrobial-resistant pathogens limit treatment options, prompting an empirical use of broad-range antibiotics. Fast and reliable diagnostic tools are needed to provide adequate therapy in a timely manner and to enable a de-escalation of treatment. The Accelerate Pheno system (Accelerate Diagnostics, USA) is a fully automated test system that performs both identification and antimicrobial susceptibility testing (AST) directly from positive blood cultures within approximately 7 h. In total, 115 episodes of BSI with Gram-negative bacteria were included in our study and compared to conventional culture-based methods. The Accelerate Pheno system correctly identified 88.7% (102 of 115) of all BSI episodes and 97.1% (102 of 105) of isolates that are covered by the system's identification panel. The Accelerate Pheno system generated an AST result for 91.3% (95 of 104) samples in which the Accelerate Pheno system identified a Gram-negative pathogen. The overall category agreement between the Accelerate Pheno system and culture-based AST was 96.4%, the rates for minor discrepancies 1.4%, major discrepancies 2.3%, and very major discrepancies 1.0%. Of note, ceftriaxone, piperacillin-tazobactam, and carbapenem resistance was correctly detected in blood culture specimens with extended-spectrum beta-lactamase-producing ( = 7) and multidrug-resistant ( = 3) strains. The utilization of the Accelerate Pheno system reduced the time to result for identification by 27.49 h ( < 0.0001) and for AST by 40.39 h ( < 0.0001) compared to culture-based methods in our laboratory setting. In conclusion, the Accelerate Pheno system provided fast, reliable results while significantly improving turnaround time in blood culture diagnostics of Gram-negative BSI.
血流感染（BSI）是发病和死亡的重要原因。抗菌病原体耐药率不断上升限制了治疗选择，促使经验性使用广谱抗生素。需要快速可靠的诊断工具以便及时提供充分治疗并实现降阶梯治疗。Accelerate Pheno系统（美国Accelerate Diagnostics公司）是一种全自动检测系统，可在约7小时内直接从阳性血培养物中同时进行鉴定和抗菌药物敏感性测试（AST）。我们的研究共纳入了115例革兰氏阴性菌血流感染病例，并与传统的基于培养的方法进行比较。Accelerate Pheno系统正确鉴定了所有血流感染病例中的88.7%（115例中的102例）以及系统鉴定面板涵盖的分离株中的97.1%（105例中的102例）。Accelerate Pheno系统对91.3%（104例中的95例）其鉴定出革兰氏阴性病原体的样本生成了AST结果。Accelerate Pheno系统与基于培养的AST之间的总体类别一致性为96.4%，轻微差异率为1.4%，主要差异率为2.3%，非常主要差异率为1.0%。值得注意的是，在产超广谱β-内酰胺酶（n = 7）和多重耐药（n = 3）菌株的血培养标本中，头孢曲松、哌拉西林-他唑巴坦和碳青霉烯耐药性被正确检测到。与我们实验室环境中基于培养的方法相比，使用Accelerate Pheno系统将鉴定结果报告时间缩短了27.49小时（P < 0.000），AST结果报告时间缩短了40.39小时（P < 0.000）。总之，Accelerate Pheno系统提供了快速、可靠的结果，同时显著缩短了革兰氏阴性菌血流感染血培养诊断的周转时间。
