Our method is based on the use of hair-thin glass fibres to which the live bacteria being tested are fixed. Their movements are transmitted to the fibres, the vibrations of which are recorded by a laser and visualised on a computer screen. If a bacterium is susceptible to an added antibiotic, it dies and the glass fibre stops moving after about 10 to 20 minutes. If, on the other hand, the laser is still detecting movement after this time has elapsed, then the bacterium is resistant to the antibiotic that has been administered. The advantages of our method compared with conventional tests are the rapid availability of the result and the possibility of testing different antibiotics in parallel by using several glass fibres.

One of the reasons why antibiotic-resistant bacteria multiply is that patients are treated without doctors knowing exactly which bacterial strain is involved. If, however, targeted treatment based on full characterisation of the pathogen is to be given from the outset, new tests are needed that can shorten the time between patients being admitted and treatment being initiated. This will open up new options, such as the use of specific antibiotics instead of broad-spectrum antibiotics.

In addition to the purely medical benefit, our technology will be competitive in a number of ways: compared with current standards, we want to obtain faster and more comprehensive information on the antibiotics to which a pathogen is resistant and to do so at the same or lower cost.

Our new test device is suitable for analytical laboratories in hospitals because the technology can only be operated by technically trained staff. In the longer term, however, the intention is to make the test available for wider use, including in doctors’ practices, by using low-cost glass fibres and simplifying the technology.

A new rapid and reliable bacterial phenotypic diagnostic technique detecting bacterial susceptibility to antibiotics using optical fibers