Development of a rapid phenotypic test on a microfluidic device for carbapenemase detection using the chromogenic compound nitrocefin.

Routine identification of carbapenemase-producing bacterial isolates is a lengthy process often taking up to 72 h to generate results with standard culture-based tests. Here we describe a rapid test based on the hydrolysis of nitrocefin to identify isolates producing β-lactamase enzymes. A cocktail of inhibitors has been optimized in the reaction mix to provide specificity for carbapenemase enzymes.

Fast and sensitive isothermal DNA assay using microbead dielectrophoresis for detection of anti-microbial resistance genes.

Antimicrobial resistant pathogens are a growing worldwide threat to human health. This study describes a novel method for rapid and sensitive detection of antimicrobial resistance (AMR) genes, specifically bla which encodes for the enzyme that offers resistance to extended spectrum β-lactam antibiotics. The method combines isothermal DNA amplification by recombinase polymerase amplification (RPA), with microbead dielectrophoresis (DEP)-based DNA detection.

Ultra-fast electronic detection of antimicrobial resistance genes using isothermal amplification and Thin Film Transistor sensors.

A low cost thin-film transistor (TFT) nanoribbon (NR) sensor has been developed for rapid real-time detection of DNA amplification using an isothermal Recombinase Polymerase Amplification (RPA) method. The semiconductor chip measures DNA amplification through a pH change, rather than via fluorescence. The utility of the method was demonstrated by amplifying CTX-M and NDM, two genes that confer bacterial resistance to cephalosporins and carbapenems, respectively.

Simple and rapid sample preparation system for the molecular detection of antibiotic resistant pathogens in human urine.

Antibiotic resistance in urinary tract infections (UTIs) can cause significant complications without quick detection and appropriate treatment. We describe a new approach to capture, concentrate and prepare amplification-ready DNA from antibiotic resistant bacteria in human urine samples. Klebsiella pneumoniae NCTC13443 (bla CTX-M-15 positive) spiked into filtered human urine was used as a model system.

Rapid and sensitive detection of antibiotic resistance on a programmable digital microfluidic platform.

The widespread dissemination of CTX-M extended spectrum β-lactamases among Escherichia coli bacteria, both in nosocomial and community environments, is a challenge for diagnostic bacteriology laboratories. We describe a rapid and sensitive detection system for analysis of DNA containing the blaCTX-M-15 gene using isothermal DNA amplification by recombinase polymerase amplification (RPA) on a digital microfluidic platform; active matrix electrowetting-on-dielectric (AM-EWOD). The devices have 16,800 electrodes that can be independently controlled to perform multiple and simultaneous droplet operations.

Shaped apertures in photoresist films enhance the lifetime and mechanical stability of suspended lipid bilayers.

Planar lipid bilayers suspended in apertures provide a controlled environment for ion channel studies. However, short lifetimes and poor mechanical stability of suspended bilayers limit the experimental throughput of bilayer electrophysiology experiments. Although bilayers are more stable in smaller apertures, ion channel incorporation through vesicle fusion with the suspended bilayer becomes increasingly difficult.