Center for Manufacturing Innovation, Fraunhofer USA, Brookline, Massachusetts, 02446, USA.
Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, 02115, USA.
Sci Rep. 2017 Aug 14;7(1):8031. doi: 10.1038/s41598-017-07584-z.
Bacteremia is a life-threatening condition for which antibiotics must be prescribed within hours of clinical diagnosis. Since the current gold standard for bacteremia diagnosis is based on conventional methods developed in the mid-1800s-growth on agar or in broth-identification and susceptibility profiling for both Gram-positive and Gram-negative bacterial species requires at least 48-72 h. Recent advancements in accelerated phenotypic antibiotic susceptibility testing have centered on the microscopic growth analysis of small bacterial populations. These approaches are still inherently limited by the bacterial growth rate. Our approach is fundamentally different. By applying environmental stress to bacteria in a microfluidic platform, we can correctly assign antibiotic susceptibility profiles of clinically relevant Gram-negative bacteria within two hours of antibiotic introduction rather than 8-24 h. The substantial expansion to include a number of clinical isolates of important Gram-negative species-Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa-reported here underscores the broad utility of our approach, complementing the method's proven utility for Gram-positive bacteria. We also demonstrate that the platform is compatible with antibiotics that have varying mechanisms of action-meropenem, gentamicin, and ceftazidime-highlighting the versatility of this platform.
菌血症是一种危及生命的病症，必须在临床诊断后的数小时内开出抗生素。由于目前菌血症诊断的黄金标准基于 19 世纪中期发展起来的常规方法——琼脂或肉汤上的生长——因此，革兰氏阳性和革兰氏阴性细菌的鉴定和药敏分析至少需要 48-72 小时。最近，加速表型抗生素药敏检测方面的进展集中在对小细菌群体的微观生长分析上。这些方法仍然受到细菌生长速度的内在限制。我们的方法从根本上不同。通过在微流控平台上对细菌施加环境压力，我们可以在抗生素引入后两小时内正确分配临床相关革兰氏阴性细菌的抗生素药敏谱，而不是 8-24 小时。这里报告的大量扩展，包括多种重要革兰氏阴性菌的临床分离株——阴沟肠杆菌、大肠杆菌、肺炎克雷伯菌和铜绿假单胞菌——突出了我们方法的广泛适用性，补充了该方法对革兰氏阳性菌的已证明实用性。我们还证明了该平台与具有不同作用机制的抗生素兼容——美罗培南、庆大霉素和头孢他啶——突出了该平台的多功能性。
