Generation Of An Amplifiable Biosensor Based On Conjugation For Detection Of Salmonella In Food Samples
Abstract
Foodborne illness caused by ingestion of pathogens represents a significant, increasingly complex global health challenge. The gold-standard of food pathogen detection is becoming outdated, representing a reasonable target for reducing foodborne illness. The work in this thesis aims to develop and characterize an amplifiable biosensor system based on conjugation from a non-pathogenic E. coli to Salmonella for detection in food samples. The assay functions via conjugation of a plasmid pDETECT to Salmonella, inducing production of luxI and homoserine lactones, which induce fluorescent readout via pLux-driven transcription of thermal green protein (TGP) in an E. coli sensor. With optimized conditions for conjugation and fluorescent readout, the estimated current limit of detection of the assay is 104-105 CFU/mL in spiked food samples, with a total assay time ranging between 11-13 hours.