Researchers at EPFL have built a matchbox-sized device that can test for the presence of bacteria in a couple of minutes, instead of up to several weeks. A nano-lever vibrates in the presence of bacterial activity, while a laser reads the vibration and translates it into an electrical signal that can be easily readthe absence of a signal signifies the absence of bacteria. Thanks to this method, it is quick and easy to determine if a bacteria has been effectively treated by an antibiotic, a crucial medical tool especially for resistant strains. Easily used in clinics, it could also prove useful for testing chemotherapy treatment. The research is published in the latest issue of Nature Nanotechnology.
"This method is fast and accurate. And it can be a precious tool for both doctors looking for the right dosage of antibiotics and for researchers to determine which treatments are the most effective," explains Giovanni Dietler.
Laser and nanotechnology read the bacteria's metabolic activity
It currently takes a long time to measure a bacterial infection's response to antibiotic treatment. Clinicians must culture the bacteria and then observe its growth, sometimes for almost a month, as is the case with tuberculosis, in order to determine if the treatment has been effective.
Thanks to advances in laser and optical technology, the EPFL team of physicists has reduced this time to a couple of minutes. To do so, Giovanni Dietler, Sandor Kasas and Giovanni Longo have exploited the microscopic movements of a bacterium's metabolism.
These vital signs are almost unperceivable. In order to test for them, the researchers place the bacteria on an extremely sensitive measuring device that vibrates a small leveronly slightly thicker than a strand of hairin the presence of certain activity. The lever then vibrates under the metabolic activity of the germs. These infinitely small oscillations, on the order of one millionth of
|Contact: Lionel Pousaz|
Ecole Polytechnique Fdrale de Lausanne