title: Multiplex detection of microbial and plant toxins by immunoaffinity enrichment and matrix-assisted laser desorption/ionization mass spectrometry.
abstract: Plant and microbial toxins such as ricin, staphylococcal enterotoxin B (SEB), and the botulinum neurotoxins (BoNT) are considered as potential biological warfare agents. Specific screening methods are, therefore, required that enable unambiguous and sensitive identification of these biohazards, particularly for the occurrence of the toxins in complex sample matrixes. The present study describes a combination of a multiplex-immunoaffinity purification approach, followed by matrix-assisted laser desorption/ionization (MALDI)-based detection for the simultaneous identification of ricin, SEB, BoNT/A, and BoNT/B. The method comprises an affinity enrichment step, using specific monoclonal antibodies for each of the four toxins which have been selected from a pool of antibodies. The selected antibodies allow for specific and simultaneous capture of ricin, SEB, BoNT/A, BoNT/B, and the corresponding BoNT complexes. These were subsequently identified by MALDI time-of-flight (TOF) mass spectrometry (MS), following tryptic digest. The sensitivity of the technique was approximately 500 fmol for each of the toxins. These toxins were detectable within 8 h, even when present in complex matrixes such as milk or juice. Furthermore, the MALDI-based multiplex assay allowed for the discrimination of closely related BoNT sero- and subtypes, including a real case of food-borne botulism in Germany.
authors.affiliation: Biomedical Spectroscopy (P25), Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
authors.forename: Skadi
authors.initials: S
authors.lastname: Kull
authors.forename: Diana
authors.initials: D
authors.lastname: Pauly
authors.forename: Britta
authors.initials: B
authors.lastname: Störmann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kirchner
authors.forename: Maren
authors.initials: M
authors.lastname: Stämmler
authors.forename: Martin B
authors.initials: MB
authors.lastname: Dorner
authors.forename: Peter
authors.initials: P
authors.lastname: Lasch
authors.forename: Dieter
authors.initials: D
authors.lastname: Naumann
authors.forename: Brigitte G
authors.initials: BG
authors.lastname: Dorner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D055910:Antibodies, Immobilized / Q000276:immunology / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D001905:Botulinum Toxins / Q000032:analysis / Q000737:chemistry*; D004768:Enterotoxins / Q000032:analysis / Q000737:chemistry*; D005516:Food Microbiology; D018189:Immunomagnetic Separation / Q000379:methods*; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D012276:Ricin / Q000032:analysis / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors
chemical_list: D055910:Antibodies, Immobilized; D000911:Antibodies, Monoclonal; D004768:Enterotoxins; C031818:enterotoxin B, staphylococcal; D012276:Ricin; D001905:Botulinum Toxins