International Iberian Nanotechnology Laboratory (INL), Braga, Portugal.
Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal.
Biotechnol Bioeng. 2021 Aug;118(8):3164-3174. doi: 10.1002/bit.27841. Epub 2021 Jun 6.
Nosocomial or hospital-acquired infections (HAIs) have a major impact on mortality worldwide. Enterococcus and Staphylococcus are among the leading causes of HAIs and thus are important pathogens to control mainly due to their increased antibiotic resistance. The gold-standard diagnostic methods for HAIs are time-consuming, which hinders timely and adequate treatment. Therefore, the development of fast and accurate diagnostic tools is an urgent demand. In this study, we combined the sensitivity of magnetoresistive (MR) sensors, the portability of a lab-on-chip platform, and the specificity of phage receptor binding proteins (RBPs) as probes for the rapid and multiplex detection of Enterococcus and Staphylococcus. For this, bacterial cells were firstly labelled with magnetic nanoparticles (MNPs) functionalized with RBPs and then measured on the MR sensors. The results indicate that the RBP-MNPS provided a specific individual and simultaneous capture of more than 70% of Enterococcus and Staphylococcus cells. Moreover, high signals from the MR sensors were obtained for these samples, providing the detection of both pathogens at low concentrations (10 CFU/ml) in less than 2 h. Overall, the lab-on-chip MR platform herein presented holds great potential to be used as a point-of-care for the rapid, sensitive and specific multiplex diagnosis of bacterial infections.
医院获得性感染（HAI）对全球死亡率有重大影响。肠球菌和葡萄球菌是 HAI 的主要病原体之一，因此是需要主要控制的重要病原体，主要是因为它们的抗生素耐药性增加。HAI 的金标准诊断方法耗时耗力，阻碍了及时和充分的治疗。因此，开发快速准确的诊断工具是当务之急。在这项研究中，我们将磁阻（MR）传感器的灵敏度、芯片实验室平台的便携性以及噬菌体受体结合蛋白（RBP）的特异性结合起来，作为快速和多重检测肠球菌和葡萄球菌的探针。为此，首先用 RBP 功能化的磁性纳米颗粒（MNPs）标记细菌细胞，然后在 MR 传感器上进行测量。结果表明，RBP-MNPs 提供了对超过 70%肠球菌和葡萄球菌细胞的特异性个体和同时捕获。此外，这些样本的 MR 传感器获得了高信号，在不到 2 小时的时间内即可检测到低浓度（10 CFU/ml）的两种病原体。总体而言，本文提出的芯片实验室 MR 平台具有作为即时护理的潜力，可用于快速、敏感和特异性的多重细菌感染诊断。
