Rapid detection of single bacteria in unprocessed blood using Integrated Comprehensive Droplet Digital Detection

• DOI: 10.1038/ncomms6427
• Publication Date: 2014-11-13T11:10:22Z
• Authors: Dong-Ku Kang; M. Monsur Ali; Kaixiang Zhang; Susan S. Huang; Ellena Peterson; Michelle A. Digman; Enrico Gratton; Weian Zhao
• Keywords: DNA, Bacterial; Drug Compounding; 610; Sensitivity and Specificity; 01 natural sciences; Article; Limit of Detection; Sepsis; Escherichia coli; Humans; Catalytic; Biomedical and Clinical Sciences; Bacterial; Hematology; DNA; DNA, Catalytic; Biological Sciences; Microfluidic Analytical Techniques; 4.1 Discovery and preclinical testing of markers and technologies; 0104 chemical sciences; 3. Good health; Infectious Diseases; Good Health and Well Being; Blood; Medical Microbiology; Infection; Biotechnology

AbstractBlood stream infection or sepsis is a major health problem worldwide, with extremely high mortality, which is partly due to the inability to rapidly detect and identify bacteria in the early stages of infection. Here we present a new technology termed ‘Integrated Comprehensive Droplet Digital Detection’ (IC 3D) that can selectively detect bacteria directly from milliliters of diluted blood at single-cell sensitivity in a one-step, culture- and amplification-free process within 1.5–4 h. The IC 3D integrates real-time, DNAzyme-based sensors, droplet microencapsulation and a high-throughput 3D particle counter system. Using Escherichia coli as a target, we demonstrate that the IC 3D can provide absolute quantification of both stock and clinical isolates of E. coli in spiked blood within a broad range of extremely low concentration from 1 to 10,000 bacteria per ml with exceptional robustness and limit of detection in the single digit regime.