Identification of blood meal sources in the main African malaria mosquito vector by MALDI-TOF MS.

Ogobara Doumbo,Constentin Dieme,Jean-Michel Berenger,Lionel Almeras,Didier Raoult,Sirama Niare,Philippe Parola

doi:10.1186/s12936-016-1152-6

Abstract

BackgroundThe identification of blood meal sources in malaria vectors is critical to better understanding host/vector interactions and malaria epidemiology and control. Currently, the identification of mosquito blood meal origins is based on time-consuming and costly techniques such as precipitin tests, ELISA and molecular tools. Although these tools have been validated to identify the blood meal and trophic preferences of female Anopheles mosquitoes, they present several limitations. Recently, matrix-assisted, laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was successfully used as a quick and accurate tool for arthropod identification, including mosquitoes. The aim of the present work was to test whether MALDI-TOF MS could also be applied to identification of blood meal sources from engorged mosquitoes.MethodsAbdomen proteins extracted from Anopheles gambiae (stricto sensu, S molecular form) that were either unengorged or artificially engorged on seven distinct types of vertebrate blood (human, horse, sheep, rabbit, mouse, rat, dog) were submitted for MALDI-TOF MS.ResultsThe comparison of mass spectrometry (MS) spectra from mosquito abdomens collected 1 h post-feeding, were able to discriminate blood meal origins. Moreover, using Aedes albopictus specimens, abdominal protein MS spectra from engorged mosquitoes were found specific to host blood source and independent of the mosquito species. A sequential analysis revealed stability of mosquito abdominal protein spectra up to 24 h post-feeding.ConclusionsThese results indicate that MALDI-TOF MS could determine feeding patterns of freshly engorged mosquitoes up to 24 h post-blood meal. The MALDI-TOF MS technique appears to be an efficient tool for large epidemiological surveillance of vector-borne diseases and outbreak source identification.

Highlights

The identification of blood meal sources in malaria vectors is critical to better understanding host/vec‐ tor interactions and malaria epidemiology and control
To confirm that the absence of vertebrate cytochrome c oxidase I gene (vCOI) PCR product could be attributed to degradation of vertebrate blood DNA, a set of primer amplifying a fragment of 710 bp of the mosquito Cytochrome c oxidase I gene was used as described previously [LCO1490:5′-GGTCAACAAATCATAAGATATTGG-3′; HC02198: 5′-TAAACTTCAGGGTGACC AAAAAATCA-3′] [25]
Further experiments are needed to confirm the reproducibility of mass spectrometry (MS) spectra from mosquitoes of different species and genera engorged on the same vertebrate hosts, which will simplified trophic preference (TP) database increments for further identification of mosquitoes from others species engorged on same host

Summary

Introduction

The identification of blood meal sources in malaria vectors is critical to better understanding host/vec‐ tor interactions and malaria epidemiology and control. Mosquito identification is mainly based on the detection of morphological characters using taxonomic keys or on sequencing of targeted genes [5, 6] Both of these approaches present several limitations, such as the requirement of entomological skills or the lack of DNA barcoding for Anopheles population identification. The application of MALDI-TOF MS to mosquito populations demonstrated that this innovative method could unambiguously distinguish mosquito species, and specimens from the same complex and molecular forms of Anopheles gambiae stricto sensu (s.s.)(S molecular form) [9,10,11] This proteomic tool was applied to Anopheles identification at immature stages [12]. The low-cost, rapidity and robustness of MALDI-TOF MS made this tool a reliable method for arthropod identification

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