An interdisciplinary team of engineering and pharmaceutical researchers at the University of Alberta has invented a device that can rapidly identify harmful bacteria and can determine whether it is resistant to antibiotics.
The device could save precious hours in patient care and public health, and prevent the spread of drug-resistant strains of bacteria. The team’s findings are published in a paper entitled Microfluidic cantilever detects bacteria and measures their susceptibility to antibiotics in small confined volumes in the current issue of Nature Communications.
The device was designed to look for and trap different types of bacteria, then find out which antibiotics are most effective against them.
Rather than growing bacterial cultures then testing them – a commonly used and time-consuming approach – the microscopic device relies on nano-scale technology for fast results.
The main feature of the device is a cantilever – a plank that resembles a diving board – that has a microfluidic channel 25 times smaller than the width of a hair etched on its surface. The channel is coated with biomaterials, like antibodies, that harmful bacteria like E. coli or Listeria in fluid samples stick to.
When bacteria are caught, the device sends out three different signals to researchers.
‘When bacteria is detected, the cantilever’s mass changes, and it bends,’ explained Thomas Thundat, a Professor in the Department of Chemical and Materials Engineering, and the Canada Excellence Research Chair in Oil Sands Molecular Engineering.
‘This thus gives us two signals: the mass change and the bending action.’
‘By shining infrared light on the bacteria, a third signal is sent,’ he added.
‘If the bacterial absorbs the light it begins to vibrate, generating a minute amount of heat that sends a confirmation signal. Having three detection methods means there is no ambiguity.’
The research was funded through the Government of Canada’s Canada Excellence Research Chairs program.
