A Point-of-Care Micro-Laboratory for Direct Pathogen Identification in Body Fluids

摘要

We describe a prototype micro-laboratory for rapid genetic identification of bacterial pathogens from infected human body fluids. The core module of the detection platform is a microfabricated electrochemical sensor array. Picomolar amperometric detection is achieved through formation of a DNA sandwich between capture and detector probe pairs and bacterial 16S rRNA, coupled with an oxidoreductase enzymatic transducer. Using the sensor array functionalized with a panel of species-specific DNA oligonucleotide probes, detection of bacterial urinary pathogens have been demonstrated in a pilot clinical validation study demonstrating 98% sensitivity for Gram-negative pathogen detection, using conventional urine culture as the standard. Genotypic species identification is achieved within 45 minutes, compared to 1-2 days needed for standard bacterial culture technique. A biofilter has also been fabricated and validated with clinical urine specimens. Efficient concentration of the pathogens is demonstrated and replaces the need for conventional centrifugation. A microfluidic mixer to facilitate reagent mixing is also under development as part of sample preparation module. Preliminary experimental data indicate good correlation with computational simulation. These are critical milestones towards our development of an integrated point-of-care platform for pathogen detection in body fluids