title: Use of bioluminescent bacterial biosensors to investigate the role of free-living helminths as reservoirs and vectors of Salmonella.
abstract: Free-living microbivorous helminths that consume pathogenic bacteria could offer an environmental refuge for those pathogens and also, in the case of accidental ingestion, could transmit food-borne pathogens to humans and livestock. We tested this hypothesis by comparing the survival of Salmonella bacteria that had been ingested by the helminth Caenorhabditis elegans with that of the bacteria alone, in a series of experiments to mimic harsh environmental conditions. Using lux gene technology to record the in vivo growth of Salmonella we found that when inside C. elegans, the Salmonella exhibited enhanced survival at pH 2 and 3, in the presence of chlorine and when exposed to UV irradiation, thereby providing an environmental refuge or reservoir for the bacteria. On inoculating laboratory mice with C. elegans that had been fed on bioluminescent Salmonella, real-time imaging showed that animals developed a systemic bacterial infection, indicating that free-living helminths could play a role as a vector of pathogens.
authors.affiliation: University of the West of England, Frenchay Campus, BS16 1QY, Bristol, UK. Center for Infectious Disease Dynamics, Mueller Laboratory, Penn State University, University Park, PA 16802, USA. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, BS40 5DU, Bristol, UK.
authors.forename: Lizeth
authors.initials: L
authors.lastname: Lacharme-Lora
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Perkins
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Humphrey
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hudson
authors.forename: Vyv
authors.initials: V
authors.lastname: Salisbury