Identification of French Guiana sand flies using MALDI-TOF mass spectrometry with a new mass spectra library.

Agathe Chavy,Renaud Piarroux,Cécile Nabet,Magalie Demar,Thiago Vasconcelos Dos Santos,Marine Ginouves,Anne Cécile Normand,Ghislaine Prévot,Benoît De Thoisy,Arthur Kocher

doi:10.1371/journal.pntd.0007031

Abstract

Phlebotomine sand flies are insects that are highly relevant in medicine, particularly as the sole proven vectors of leishmaniasis. Accurate identification of sand fly species is an essential prerequisite for eco-epidemiological studies aiming to better understand the disease. Traditional morphological identification is painstaking and time-consuming, and molecular methods for extensive screening remain expensive. Recent studies have shown that matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a promising tool for rapid and cost-effective identification of arthropod vectors, including sand flies. The aim of this study was to validate the use of MALDI-TOF MS for the identification of Northern Amazonian sand flies. We constituted a MALDI-TOF MS reference database comprising 29 species of sand flies that were field-collected in French Guiana, which are expected to cover many of the more common species of the Northern Amazonian region, including known vectors of leishmaniasis. Carrying out a blind test, all the sand flies tested (n = 157) with a log (score) threshold greater than 1.7 were correctly identified at the species level. We confirmed that MALDI-TOF MS protein profiling is a useful tool for the study of sand flies, including neotropical species, known for their great diversity. An application that includes the spectra generated here will be available to the scientific community in the near future via an online platform.

Highlights

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) are insects of great medical relevance because they are the most frequent vectors of leishmaniasis [1,2] and transmit various other human pathogens including bacteria and viruses [3]
The newly generated MALDI-TOF MS reference database was composed of 29 sand fly species collected in the field from eight forest sites displaying various ecological niches of French Guiana
We confirm that MALDI-TOF MS protein profiling is well adapted to the identification of sand fly species, including in neotropical areas, known for its great diversity of sand fly species

Summary

Introduction

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) are insects of great medical relevance because they are the most frequent vectors of leishmaniasis [1,2] and transmit various other human pathogens including bacteria and viruses [3]. Leishmaniases are a range of diseases caused by flagellated protozoans of the genus Leishmania (Kinetoplastida: Trypanosomatidae), transmitted through the bite of an infected female sand fly [2]. The epidemiology of leishmaniasis is complex, due to the wide diversity of Leishmania and the sand fly species involved. Other Leishmania species such as L. braziliensis can be more clinically debilitating, since they can cause mucocutaneous (nose, mouth, and throat commitment) or diffuse cutaneous leishmaniasis, requiring specific medical management [4,5]

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