Biophotonic antibiotic susceptibility testing - a fast way to catch resistant pathogens

In times of rising antibiotic resistances, fast susceptibility testing methods are of utmost interest. When the antibiogram has been determined, tailored therapy can be administered. However, currently established diagnosis methods in hospital routine are cultivation based and require at least one, usually two days or more to obtain a result. Biophotonic techniques hold the potential to reduce this time to only a few hours. Here, we show how Raman spectroscopy as a powerful, label-free technique can be used to detect efficient interaction of antibiotics and bacteria. Those interactions can be identified in the bacterial Raman spectra already after 30 minutes of treatment.1 With this information, antibiotic resistances can be detected within less than 3.5 hours as is shown for vancomycin resistant enterococci (VRE).2 When applied directly to patient’s samples, the method has to be combined with a sample pre-treatment step to capture the bacteria from the body fluid. Two microfluidic approaches are presented, the first one utilizing centrifugal forces on a lab-on-a-disc 3, the second one using dielectrophoretic capturing 2,4. Financial support by the BMBF (CSCC, FKZ 01EO1502 and InfectoGnostics) is highly acknowledged. References: 1 Anal. Bioanal. Chem. 2015, 407, 8343 2 Sci. Rep. 2015, 5, 8271. 3 Biomicrofluidics 2015, 9, 044118. 4 Anal. Chem. 2013, 85, 10717.