title: Direct detection and drug-resistance profiling of bacteremias using inertial microfluidics.
abstract: Detection of bacteria in bloodstream infections and their antibiotic susceptibility patterns is critical to guide therapeutic decision-making for optimal patient care. Current culture-based assays are too slow (>48 h), leading to excessive up-front use of broad-spectrum antibiotics and/or incorrect antibiotic choices due to resistant bacteria, each with deleterious consequences for patient care and public health. To approach this problem, we describe a method to rapidly isolate bacteria from whole blood using inertial microfluidics and directly determine pathogen identity and antibiotic susceptibility with hybridization-based RNA detection. Using the principle of Dean flow fractionation, bacteria are separated from host blood cells in a label-free separation method with efficient recovery of even low abundance bacteria. Ribosomal RNA detection can then be applied for direct identification of low abundance pathogens (~100 per mL) from blood without culturing or enzymatic amplification. Messenger RNA detection of antibiotic-responsive transcripts after brief drug exposure permits rapid susceptibility determination from bacteria with minimal culturing (~10(5) per mL). This unique coupling of microfluidic cell separation with RNA-based molecular detection techniques represents significant progress towards faster diagnostics (~8 hours) to guide antibiotic therapy.
authors.affiliation: Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. jyhan@mit.edu.
authors.forename: Han Wei
authors.initials: HW
authors.lastname: Hou
authors.forename: Roby P
authors.initials: RP
authors.lastname: Bhattacharyya
authors.forename: Deborah T
authors.initials: DT
authors.lastname: Hung
authors.forename: Jongyoon
authors.initials: J
authors.lastname: Han
mesh_terms: D016470:Bacteremia / Q000097:blood / Q000382:microbiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D056656:Lab-On-A-Chip Devices; D012329:RNA, Bacterial / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics*; D021521:Ribotyping / Q000295:instrumentation / Q000379:methods
chemical_list: D012329:RNA, Bacterial; D012335:RNA, Ribosomal