Characterization of Bacterial Plasmids on a Smartphone

Fredrik Westerlund of Chalmers University of Technology in Sweden will develop a portable device for low-income settings based on a smartphone to identify antimicrobial resistance genes on bacterial plasmid DNA, which is a major source of antibiotic resistance. Plasmids are small pieces of circular DNA that are readily transferred between different bacteria. Current methods for characterizing them are costly and require sophisticated equipment. They have developed a simple assay that detects differences in fluorescence intensities emitted from a plasmid to generate a unique optical barcode that reflects the underlying DNA sequence. These barcodes can be used to measure the numbers and sizes of plasmids in a sample, as well as to identify specific resistance genes using the CRISPR-Cas9 genetic modification technique. They will adapt this optical mapping assay for use on a smartphone with attachable camera, and test their device in the field.