Identification of Algerian Field-Caught Phlebotomine Sand Fly Vectors by MALDI-TOF MS

Abstract

BackgroundPhlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as an accurate tool for arthropod identification. The objective of the present study was to investigate the usefulness of MALDI-TOF MS as a tool for identifying field-caught phlebotomine.Methodology/Principal FindingsSand flies were captured in four sites in north Algeria. A subset was morphologically and genetically identified. Six species were found in these areas and a total of 28 stored frozen specimens were used for the creation of the reference spectrum database. The relevance of this original method for sand fly identification was validated by two successive blind tests including the morphological identification of 80 new specimens which were stored at -80°C, and 292 unknown specimens, including engorged specimens, which were preserved under different conditions. Intra-species reproducibility and inter-species specificity of the protein profiles were obtained, allowing us to distinguish specimens at the gender level. Querying of the sand fly database using the MS spectra from the blind test groups revealed concordant results between morphological and MALDI-TOF MS identification. However, MS identification results were less efficient for specimens which were engorged or stored in alcohol. Identification of 362 phlebotomine sand flies, captured at four Algerian sites, by MALDI-TOF MS, revealed that the subgenus Larroussius was predominant at all the study sites, except for in M’sila where P. (Phlebotomus) papatasi was the only sand fly species detected.ConclusionThe present study highlights the application of MALDI-TOF MS for monitoring sand fly fauna captured in the field. The low cost, reliability and rapidity of MALDI-TOF MS analyses opens up new ways in the management of phlebotomine sand fly-borne diseases.

Comparative analysis of storage conditions and homogenization methods for tick and flea species for identification by MALDI‐TOF MS

“…software (Bruker Daltonics). DB1 included 915 MSPs from eight arthropod families, corresponding to the total MSPs of adult mosquito legs and larvae (Yssouf et al, 2013b(Yssouf et al, ,2014aDieme et al, 2014), tick legs and haemolymph (Yssouf et al, 2013a(Yssouf et al, , 2015a(Yssouf et al, , 2015b as well as sandfly and flea thoraces (Yssouf et al, 2014b;Lafri et al, 2016), which were principally homogenized manually. LSVs reflected MS spectral similarity with reference MS spectra from DB1.…”

Identification of French Guiana anopheline mosquitoes by MALDI-TOF MS profiling using protein signatures from two body parts

“…Protein mass profiles were obtained using a Microflex LT MALDI-TOF Mass Spectrometer (Bruker Daltonics, Germany), with detection in the linear positive-ion mode at a laser frequency of 50 Hz within a mass range of 2-20 kDa. The setting parameters of the MALDI-TOF MS apparatus were identical to those previously used [44].…”

“…The reliability of species identification was estimated using the log score values (LSVs) obtained from the MALDI Biotyper software v.3.0, which ranged from 0 to 3. According to previous studies [26,44], LSVs greater than 1.8 were considered reliable for species identification. Data were analyzed by using GraphPad Prism software version 5.01 (GraphPad, San Diego, CA, USA).…”

MALDI-TOF MS as an innovative tool for detection of Plasmodium parasites in Anopheles mosquitoes

“…This blind test was performed against our in-lab database, composed of the present CT spectra from P. berghei -infected and non-infected An. stephensi , and also spectra from other arthropod species listed in Table 2 [12, 15–18]. The identification level of significance was determined using the log score values (LSVs) given by the MALDI-Biotyper software v.3.3., corresponding to a matched degree of signal intensities of mass spectra of the query and the reference spectra.…”