Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
PLoS One. 2012;7(7):e41245. doi: 10.1371/journal.pone.0041245. Epub 2012 Jul 27.
This article describes Bacteria ID Chips ('BacChips'): an inexpensive, portable, and autonomous microfluidic platform for identifying pathogenic strains of bacteria. BacChips consist of a set of microchambers and channels molded in the elastomeric polymer, poly(dimethylsiloxane) (PDMS). Each microchamber is preloaded with mono-, di-, or trisaccharides and dried. Pressing the layer of PDMS into contact with a glass coverslip forms the device; the footprint of the device in this article is ∼6 cm(2). After assembly, BacChips are degased under large negative pressure and are stored in vacuum-sealed plastic bags. To use the device, the bag is opened, a sample containing bacteria is introduced at the inlet of the device, and the degased PDMS draws the sample into the central channel and chambers. After the liquid at the inlet is consumed, air is drawn into the BacChip via the inlet and provides a physical barrier that separates the liquid samples in adjacent microchambers. A pH indicator is admixed with the samples prior to their loading, enabling the metabolism of the dissolved saccharides in the microchambers to be visualized. Importantly, BacChips operate without external equipment or instruments. By visually detecting the growth of bacteria using ambient light after ∼4 h, we demonstrate that BacChips with ten microchambers containing different saccharides can reproducibly detect the ESKAPE panel of pathogens, including strains of: Enterococcus faecalis, Enteroccocus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter aerogenes, and Enterobacter cloacae. This article describes a BacChip for point-of-care detection of ESKAPE pathogens and a starting point for designing multiplexed assays that identify bacterial strains from clinical samples and simultaneously determine their susceptibility to antibiotics.
本文介绍了细菌 ID 芯片（“BacChips”）：一种廉价、便携且自主的微流控平台，可用于鉴定致病菌株。BacChips 由一组微室和通道组成，这些微室和通道采用弹性聚合物聚二甲基硅氧烷（PDMS）模制而成。每个微室都预先加载了单糖、二糖或三糖，并进行了干燥处理。将 PDMS 层压到玻璃盖玻片上即可形成器件；本文中器件的足迹约为 6 cm²。组装完成后，BacChips 在大负压下脱气，并储存在密封的塑料袋中。要使用该设备，先打开袋子，将含有细菌的样品引入设备入口，脱气后的 PDMS 将样品吸入中央通道和微室中。入口处的液体消耗完后，空气通过入口被吸入 BacChip，形成物理屏障，将相邻微室中的液体样品隔开。在加载样品之前，将 pH 指示剂与样品混合，从而可以可视化微室中溶解的糖的代谢情况。重要的是，BacChips 无需外部设备或仪器即可运行。通过在约 4 小时后使用环境光来目视检测细菌的生长，我们证明了含有十个微室的 BacChips 可以重复检测 ESKAPE 病原体组，包括以下菌株：粪肠球菌、屎肠球菌、金黄色葡萄球菌、肺炎克雷伯菌、鲍曼不动杆菌、铜绿假单胞菌、产气肠杆菌和阴沟肠杆菌。本文介绍了一种用于即时检测 ESKAPE 病原体的 BacChip，以及设计用于从临床样本中鉴定细菌菌株并同时确定其对抗生素敏感性的多重分析的起点。
