BactoSpin: Novel Technology for Rapid Bacteria Detection and Antibiotic Susceptibility Testing.

Inappropriate use of antibiotics is one of the leading causes of the increasing numbers of resistant bacteria strains, resulting in 700,000 deaths worldwide each year. Reducing unnecessary use of antibiotics and choosing the most effective antibiotics instead of broad-spectrum drugs will slow the arms race between germs and humans. Urinary tract infections (UTIs) are among the most common bacterial infections. Currently, accurate diagnosis of UTI requires approximately 48 h from the time of urine sample collection until antibiotic susceptibility test (AST) results. This work presents a rapid bacterial detection device that integrates a centrifuge, microscope, and incubator. Two disposable microfluidic chips were developed. The first chip was designed for bacteria concentration, detection, and medium exchange. A second multi-channel chip was developed for AST. This chip contains superhydrophobic and hydrophilic coatings to ensure liquid separation between the channels without the need for valves. The designed chips supported the detection of E. coli at a concentration as low as 5 × 103 cells/mL within 5 min and AST in under 2 h. AST was also successfully performed with Klebsiella pneumonia isolated from a human urine sample. In addition, machine-learning-based image recognition was shown to reduce the required time for AST and to provide results within 1 h for E. coli cells. Thus, the BactoSpin device can serve as an efficient and rapid platform for UTI diagnostics and AST.

Sequence-encoded self-assembly of multiple-nanocomponent arrays by 2D DNA scaffolding.

Regular 2D arrays of multiple types of nanocomponents were constructed by self-assembly to DNA scaffolding with alternating rows of sequence-encoded hybridization sites. Different-sized Au particles coated with DNA complementary to one of the sites were bound to the scaffolding, producing alternating rows of the two nanocomponents with a 32-nm inter-row spacing. These results demonstrate the potential for using DNA to self-assemble complex arrays of components with nanometer-scale precision.