title: Microconductometric immunosensor for label-free and sensitive detection of Gram-negative bacteria.
abstract: Blood safety is a global health goal. In developed countries, bacterial contamination of platelet concentrates is the highest infectious risk in transfusion despite the current preventive strategies. We aimed to develop a conductometric biosensor for the generic, rapid and sensitive detection of Gram-negative bacteria. Our strategy is based on immunosensors: addressable magnetic nanoparticles coupled with anti-LPS antibodies were used for the generic capture of Gram-negative bacteria. Bacterial capture was characterized by impedancemetric and microscopic measurements. The results obtained with conductometric measurements allowed real-time, sensitive detection of Escherichia coli or Serratia marcescens cultures from 1 to 10(3) CFU mL(-1). The ability of the immunosensor to detect Gram negative bacteria was also tested on clinically relevant strains. The conductometric immunosensor allowed the direct detection of 10-10(3) CFU mL(-1) of Pseudomonas aeruginosa and Acinetobacter baumannii strains that were undetectable using standard immunoblot methods. Results showed that the conductometric response was not inhibited in 1% serum.
authors.affiliation: Etablissement Français du Sang, Laboratoire TransDiag, Parc Euromédecine, 392 Avenue Professeur Jean-Louis Viala, 34184 Montpellier, France; Université de Lyon, Institut des Sciences Analytiques, UMR CNRS 5280, 5 Rue de La Doua, 69100 Villeurbanne, France.
authors.forename: Sarra
authors.initials: S
authors.lastname: El Ichi
authors.affiliation: Etablissement Français du Sang, Laboratoire TransDiag, Parc Euromédecine, 392 Avenue Professeur Jean-Louis Viala, 34184 Montpellier, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Leon
authors.affiliation: Etablissement Français du Sang, Laboratoire TransDiag, Parc Euromédecine, 392 Avenue Professeur Jean-Louis Viala, 34184 Montpellier, France.
authors.forename: Ludivine
authors.initials: L
authors.lastname: Vossier
authors.affiliation: CHRU Montpellier, Laboratoire de Bactériologie UMR 5119, Université Montpellier 2, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Helene
authors.initials: H
authors.lastname: Marchandin
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS 5280, 5 Rue de La Doua, 69100 Villeurbanne, France.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Errachid
authors.affiliation: Etablissement Français du Sang, Laboratoire TransDiag, Parc Euromédecine, 392 Avenue Professeur Jean-Louis Viala, 34184 Montpellier, France.
authors.forename: Joliette
authors.initials: J
authors.lastname: Coste
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS 5280, 5 Rue de La Doua, 69100 Villeurbanne, France. Electronic address: nicole.jaffrezic@univ-lyon1.fr.
authors.forename: Nicole
authors.initials: N
authors.lastname: Jaffrezic-Renault
authors.affiliation: Etablissement Français du Sang, Laboratoire TransDiag, Parc Euromédecine, 392 Avenue Professeur Jean-Louis Viala, 34184 Montpellier, France. Electronic address: chantal.fournier@efs.sante.fr.
authors.forename: Chantal
authors.initials: C
authors.lastname: Fournier-Wirth
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D003217:Conductometry / Q000379:methods*; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D055910:Antibodies, Immobilized; D058185:Magnetite Nanoparticles
keywords: Blood safety; Conductometric transduction; Gram-negative bacteria; Label free detection; Magneto-immunoassay