title: Identification of phlebotomine sand flies using one MALDI-TOF MS reference database and two mass spectrometer systems.
abstract: BACKGROUND
  Rapid, accurate and high-throughput identification of vector arthropods is of paramount importance in surveillance programmes that are becoming more common due to the changing geographic occurrence and extent of many arthropod-borne diseases. Protein profiling by MALDI-TOF mass spectrometry fulfils these requirements for identification, and reference databases have recently been established for several vector taxa, mostly with specimens from laboratory colonies.
  
  
  METHODS
  We established and validated a reference database containing 20 phlebotomine sand fly (Diptera: Psychodidae, Phlebotominae) species by using specimens from colonies or field-collections that had been stored for various periods of time.
  
  
  RESULTS
  Identical biomarker mass patterns ('superspectra') were obtained with colony- or field-derived specimens of the same species. In the validation study, high quality spectra (i.e. more than 30 evaluable masses) were obtained with all fresh insects from colonies, and with 55/59 insects deep-frozen (liquid nitrogen/-80 °C) for up to 25 years. In contrast, only 36/52 specimens stored in ethanol could be identified. This resulted in an overall sensitivity of 87 % (140/161); specificity was 100 %. Duration of storage impaired data counts in the high mass range, and thus cluster analyses of closely related specimens might reflect their storage conditions rather than phenotypic distinctness. A major drawback of MALDI-TOF MS is the restricted availability of in-house databases and the fact that mass spectrometers from 2 companies (Bruker, Shimadzu) are widely being used. We have analysed fingerprints of phlebotomine sand flies obtained by automatic routine procedure on a Bruker instrument by using our database and the software established on a Shimadzu system. The sensitivity with 312 specimens from 8 sand fly species from laboratory colonies when evaluating only high quality spectra was 98.3 %; the specificity was 100 %. The corresponding diagnostic values with 55 field-collected specimens from 4 species were 94.7 % and 97.4 %, respectively.
  
  
  CONCLUSIONS
  A centralized high-quality database (created by expert taxonomists and experienced users of mass spectrometers) that is easily amenable to customer-oriented identification services is a highly desirable resource. As shown in the present work, spectra obtained from different specimens with different instruments can be analysed using a centralized database, which should be available in the near future via an online platform in a cost-efficient manner.
authors.affiliation: Swiss National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Winterthurerstrasse 266a, 8057, Zürich, Switzerland. alexander.mathis@uzh.ch.
authors.forename: Alexander
authors.initials: A
authors.lastname: Mathis
authors.affiliation: Université de Reims Champagne-Ardenne, ANSES, EA4688 - USC "transmission vectorielle et épidémiosurveillance de maladies parasitaires (VECPAR)", SFR Cap Santé, 51, rue Cognacq-Jay, 51096, Reims, France. jerome.depaquit@univ-reims.fr.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Depaquit
authors.affiliation: Department of Parasitology, Faculty of Sciences, Charles University in Prague, Vinicna 7, 128 44, Prague 2, Czech Republic. icejumper@seznam.cz.
authors.forename: Vit
authors.initials: V
authors.lastname: Dvořák
authors.affiliation: Swiss National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Winterthurerstrasse 266a, 8057, Zürich, Switzerland. htuten@gmail.com.|Current address: NSF Center for Integrated Pest Management, 1730 Varsity Drive, Suite 110, Venture IV Building, Raleigh, North Carolina, 27606, USA. htuten@gmail.com.
authors.forename: Holly
authors.initials: H
authors.lastname: Tuten
authors.affiliation: MIVEGEC, UMR CNRS-IRD-Université de Montpellier Centre IRD, 911 Avenue Agropolis, BP 64501, , Cedex 34394, Montpellier, France. anne-laure.banuls@ird.fr.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Bañuls
authors.affiliation: Laboratory of Molecular Structure Characterization, Institute of Microbiology, The Czech Academy of Sciences, Videnska 1083, 142 20, Prague 4, Czech Republic. halada@biomed.cas.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Halada
authors.affiliation: Instituto de Microbiología, Universidad San Francisco de Quito, Diego de Robles S/N, Quito, Ecuador. szapata@usfq.edu.ec.
authors.forename: Sonia
authors.initials: S
authors.lastname: Zapata
authors.affiliation: Université de Reims Champagne-Ardenne, ANSES, EA4688 - USC "transmission vectorielle et épidémiosurveillance de maladies parasitaires (VECPAR)", SFR Cap Santé, 51, rue Cognacq-Jay, 51096, Reims, France. veronique.lehrter@univ-reims.fr.
authors.forename: Véronique
authors.initials: V
authors.lastname: Lehrter
authors.affiliation: Department of Parasitology, Faculty of Sciences, Charles University in Prague, Vinicna 7, 128 44, Prague 2, Czech Republic. hlavackova.k@centrum.cz.
authors.forename: Kristýna
authors.initials: K
authors.lastname: Hlavačková
authors.affiliation: MIVEGEC, UMR CNRS-IRD-Université de Montpellier Centre IRD, 911 Avenue Agropolis, BP 64501, , Cedex 34394, Montpellier, France. Jorian.Prudhomme@hotmail.fr.
authors.forename: Jorian
authors.initials: J
authors.lastname: Prudhomme
authors.affiliation: Department of Parasitology, Faculty of Sciences, Charles University in Prague, Vinicna 7, 128 44, Prague 2, Czech Republic. volf@cesnet.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Volf
authors.affiliation: MIVEGEC, UMR CNRS-IRD-Université de Montpellier Centre IRD, 911 Avenue Agropolis, BP 64501, , Cedex 34394, Montpellier, France. denis.sereno@ird.fr.
authors.forename: Denis
authors.initials: D
authors.lastname: Sereno
authors.affiliation: Swiss National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Winterthurerstrasse 266a, 8057, Zürich, Switzerland. anopheles@swissonline.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Kaufmann
authors.affiliation: Mabritec SA, Lörracherstrasse 50, 4125, Riehen, Switzerland. Valentin.Pflueger@mabritec.com.
authors.forename: Valentin
authors.initials: V
authors.lastname: Pflüger
authors.affiliation: Swiss National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Winterthurerstrasse 266a, 8057, Zürich, Switzerland. francis.schaffner@uzh.ch.|Avia-GIS, Risschotlei 33, 2980, Zoersel, Belgium. francis.schaffner@uzh.ch.
authors.forename: Francis
authors.initials: F
authors.lastname: Schaffner
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000235:genetics; D004772:Entomology / Q000379:methods*; D019476:Insect Proteins / Q000032:analysis*; D008969:Molecular Sequence Data; D011576:Psychodidae / Q000737:chemistry* / Q000145:classification*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013696:Temperature
chemical_list: D019476:Insect Proteins; D003576:Electron Transport Complex IV