title: Phage-Based Fluorescent Biosensor Prototypes to Specifically Detect Enteric Bacteria Such as E. coli and Salmonella enterica Typhimurium.
abstract: Water safety is a major concern for public health and for natural environment preservation. We propose to use bacteriophages to develop biosensor tools able to detect human and animal pathogens present in water. For this purpose, we take advantage of the highly discriminating properties of the bacteriophages, which specifically infect their bacterial hosts. The challenge is to use a fluorescent reporter protein that will be synthesized, and thus detected, only once the specific recognition step between a genetically modified temperate bacteriophage and its bacterial host has occurred. To ensure the accuracy and the execution speed of our system, we developed a test that does not require bacterial growth, since a simple 1-hour infection step is required. To ensure a high sensitivity of our tool and in order to detect up to a single bacterium, fluorescence is measured using a portable flow cytometer, also allowing on-site detection. In this study, we have constructed and characterized several "phagosensor" prototypes using the HK620 bacteriophage and its host Escherichia coli TD2158 and we successfully adapted this method to Salmonella detection. We show that the method is fast, robust and sensitive, allowing the detection of as few as 10 bacteria per ml with no concentration nor enrichment step. Moreover, the test is functional in sea water and allows the detection of alive bacteria. Further development will aim to develop phagosensors adapted on demand to the detection of any human or animal pathogen that may be present in water.
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR7283, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Vinay
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR7283, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Franche
authors.affiliation: Aix-Marseille Université, Université Sud Toulon Var, IRD, CNRS, Mediterranean Institute of Oceanology UM110, Marseille, France.
authors.forename: Gérald
authors.initials: G
authors.lastname: Grégori
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR7283, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
authors.forename: Jean-Raphaël
authors.initials: JR
authors.lastname: Fantino
authors.affiliation: Pherecydes-Pharma, Romainville, France.
authors.forename: Flavie
authors.initials: F
authors.lastname: Pouillot
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR7283, Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Ansaldi
mesh_terms: D001435:Bacteriophages / Q000235:genetics*; D015374:Biosensing Techniques; D004926:Escherichia coli / Q000378:metabolism* / Q000821:virology; D005814:Genes, Viral; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D030781:Organisms, Genetically Modified; D012486:Salmonella typhimurium / Q000378:metabolism* / Q000821:virology; D012623:Seawater / Q000382:microbiology; D012680:Sensitivity and Specificity; D014871:Water Microbiology; D060753:Water Quality
chemical_list: D049452:Green Fluorescent Proteins