Despite the modern use of mass spectrometry, identifying infection-causing bacteria is currently a drawn out process that involves culturing bacteria on agar prior to phenotypic analysis. Now, scientists at Lausanne’s University Hospital have devised a new technique that removes the need to culture bacterial on agar plates, cutting diagnosis times by eight hours.
Instead, bacteria from blood culture bottles are prepared by differential centrifugation and addition of a treatment solution. The bacteria can then be identified directly by MALDI-TOF mass spectrometry.
The inventors have demonstrated that their sample preparation method, coupled with MALDI-TOF mass spectrometry, enabled bacteria to be identified correctly in more than 78 per cent of the cases.
This technique is applicable to the routine bacterial identification of blood cultures in clinical laboratory and holds several advantages:
Time taken to identify bacteria is reduced by eight hours, compared to culturing on agar plates and then using MADLI-TOF.
Reduced costs of bacterial identification.
Easy to handle by a technician.
This time and cost saving method is already used in Lausanne’s University Hospital. Having completed the proof-of-concept phase, the University Hospital is seeking to develop a commercial kit, and a patent has been filed (EP09175757.5).