An integrated microfluidic system for antibiotic resistance gene identification capable differentiating live and dead of vancomycin-resistant enterococcus

This study presents an integrated microfluidic system which can identify the vancomycin resistant gene (vanA) from live hetero-bacteria automatically. In this study, a new approach to diagnose the vanA gene from live hetero-bacteria by using ethidium monoazide (EMA) and loop-mediated isothermal amplification (LAMP) was proposed and its feasibility was tested and verified. In addition, an integrated microfluidic system including a microfluidic chip and a home-made control system was also demonstrated. The experimental results showed that the developed system can detect the vanA gene from “live” Enterococcus but not “dead” Enterococcus successfully with a detection limit of 10 colony formation units (CFU). The entire process including the sample pre-treatment process could be automated within 1 hour. This is the first time that an integrated microfluidic system was demonstrated to diagnose the vanA gene from live bacteria by using a molecular diagnosis approach. With its high sensitivity and accuracy, the proposed system may be promising to verify antibiotic resistance genes from live hetero-bacteria which cannot be achieved by using the existing diagnostic methods.