a1 Vector Entomology Unit, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
a2 Mabritec SA, Riehen, Switzerland
Culicoides biting midges are of great importance as vectors of pathogens and elicitors of allergy. As an alternative for the identification of these tiny insects, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) was evaluated. Protein mass fingerprints were determined for 4–5 field-caught reference (genetically confirmed) individuals of 12 Culicoides species from Switzerland, C. imicola from France, laboratory-reared C. nubeculosus and a non-biting midge. Reproducibility and accuracy of the database was tested in a validation study by analysing 108 mostly field-caught target Culicoides midges and 3 specimens from a non-target species. A reference database of biomarker mass sets containing between 24 and 38 masses for the different species could be established. Automated database-based identification was achieved for 101 of the 108 specimens. The remaining 7 midges required manual full comparison with the reference spectra yielding correct identification for 6 specimens and an ambiguous result for the seventh individual. Specimens of the non-target species did not yield identification. Protein profiling by MALDI-TOF, which is compatible with morphological and genetic identification of specimens, can be used as an alternative, quick and inexpensive tool to accurately identify Culicoides biting midges collected in the field.
(Received June 27 2011)
(Revised August 30 2011)
(Accepted September 05 2011)
(Online publication October 19 2011)
c1 Corresponding author: Vector Entomology Unit, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 266a, CH-8057 Zürich, Switzerland. Tel: +41 44 635 85 01. Fax: +41 44 635 89 07. E-mail: firstname.lastname@example.org