D5 – A bacterial detection platform
Demonstrator leader: David Olea (AlphaSip)
The diagnosis of Streptococcus pneumoniae, the most common cause of bacterial pneumonia accounting for over 30% of the total pneumonia caseload, at least 50% of the cases in the developing world, and probably a higher proportion of fatal cases is nowadays based on conventional culture of samples from the patient (a technique from the times of Louis Pasteur). Although this technique is simple and cheap, results are obtained rather late (2-3 days). As a result, it becomes a clear threat for many cases where the infection grows quickly. Recently, microfluidic devices using PCR (Polymerase Chain Reaction) and amperometric detection has been developed for a quick detection of Streptococcus pneumonia (2-3 hours). This detection method has been awarded with the first price of the International Dropsens Award 2014 (to the best research work in applied electroanalytical chemistry). Furthermore, positive results were obtained during a pre-clinical validation at Hospital La Paz (Madrid, Spain).
Artist impression of the bacteria detection platform.
In this project, polymer based microfluidic technology integrating silicon based chips will be used for the development and fabrication of first devices. Polymer microfluidics will allow the required liquid handling and will provide the microchamber where the PCR will take place using external heaters. A silicon chip will be included to provide the electrodes needed to perform amperometric detection. Moreover, integrated electronics will be present in the silicon chip next to the amperometric electrodes to optimize signal-to-noise ratio. As a result, high sensitivity and specificity levels are expected. Sample preparation will be performed inside the microfluidic device using silica particles for DNA extraction. A portion of the LytA gene specific to Streptococcus pneumonia will then be amplified by direct asymmetric PCR using specific probes conjugated to magnetic beads and labelled with HRP (Horse Radish Peroxidase) for final amperometric based detection.