A DIAGNOSTIC TOOL FOR IN VIVO SCREENING OF BIOMARKERS
Inflammatory bowel disease (IBD) results in chronic inflammation of the intestines. Current diagnostic methods are invasive and rely on biomarkers that are not sufficiently disease-specific. We have engineered E. coli to detect several disease-specific biomarkers, memorize this event, and allow specific readout of the memory state. While the sensor cells travel through the gut, simultaneously occurring signals are memorized by activating an AND gate which triggers a recombination-based unidirectional switch and commits the observation to memory. After isolation from the patient’s faeces, the memory can be read out through the expression of a fluorescent protein induced by the addition of the candidate biomarker. Thus a single fluorescent protein can differentiate between many different candidate markers. A community of sensor cells can be utilized at the same time, enabling a high degree of multiplexing. Pavlov’s Coli is a non-invasive diagnostic tool for a large selection of specific biomarkers associated with IBD.