New diagnostic chip offers faster diagnosis of antibiotic-resistant bacteria

Canadian researchers have been able to develop a small and simple chip to rapidly test for antibiotic resistance.

The chip, developed by the University of Toronto, concentrates bacteria in a small space of only two nanolitres in volume in order to increase the effective concentration of the starting sample.

This nano-sized well contains an antibiotic and a signal molecule called resazurin, which is  metabolised by living bacteria into a form called resorufin, whereas this process is halted if the bacteria are effectively killed by the antibiotic.

Electrodes built directly into the chip detect the change in current as resazurin changes to resorufin, allowing users to identify whether the bacteria have antibiotic resistance in around an hour, rather than days.

The chip has been designed to be small enough to fit into a small benchtop instrument, allowing it to be easily used in a doctor's office.

PhD researcher Justin Besant said: "The next step would be to create a device that would allow you to test many different antibiotics at many different concentrations, but we're not there yet."