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

Abstract

BackgroundMalaria is still a major public health issue worldwide, and one of the best approaches to fight the disease remains vector control. The current methods for mosquito identification include morphological methods that are generally time-consuming and require expertise, and molecular methods that require laboratory facilities with relatively expensive running costs. Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) technology, routinely used for bacterial identification, has recently emerged in the field of entomology. The aim of the present study was to assess whether MALDI-TOF MS could successfully distinguish Anopheles stephensi mosquitoes according to their Plasmodium infection status.MethodsC57BL/6 mice experimentally infected with Plasmodium berghei were exposed to An. stephensi bites. For the determination of An. stephensi infection status, mosquito cephalothoraxes were dissected and submitted to mass spectrometry analyses and DNA amplification for molecular analysis. Spectra were grouped according to mosquitoes’ infection status and spectra quality was validated based on intensity and reproducibility within each group. The in-lab MALDI-TOF MS arthropod reference spectra database, upgraded with representative spectra from both groups (infected/non-infected), was subsequently queried blindly with cephalothorax spectra from specimens of both groups.ResultsThe MALDI TOF MS profiles generated from protein extracts prepared from the cephalothorax of An. stephensi allowed distinction between infected and uninfected mosquitoes. Correct classification was obtained in blind test analysis for (79/80) 98.75% of all mosquitoes tested. Only one of 80 specimens, an infected mosquito, was misclassified in the blind test analysis.ConclusionsMatrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry appears to be a promising, rapid and reliable tool for the epidemiological surveillance of Anopheles vectors, including their identification and their infection status.

Molecular and MALDI-TOF identification of ticks and tick-associated bacteria in Mali

“…MALDI-TOF MS has revolutionized clinical microbiology by its use in the routine identification of bacteria [ 41 , 42 ] and archaea [ 43 ]. Even if the MALDI-TOF MS device acquisition could be expensive, its use for entomological analyzes induces low additional costs because reagents used for this high-throughput technique are economical and data analyses are simple and rapid compared to morphological and molecular methods [ 44 ]. This fast, economical and accurate proteomic tool has since been applied to the identification of arthropods: culicoides biting midges [ 45 ], mosquitoes[ 39 , 46 , 47 ], phlebotomine sand flies [ 48 , 49 ], fleas [ 30 ] and tsetse flies [ 50 , 51 ].…”

“…More recently, preliminary studies have investigated the capacity of MALDI-TOF MS to differentiate ticks infected or not by Borrelia spp . or spotted fever group rickettsiae [ 25 – 27 ], and to detect the Plasmodium in anopheles [ 44 ]. However, tick collection is usually far from the analytical laboratories, requiring proper storage of samples.…”

Use of MALDI-TOF MS for the Identification of Chad Mosquitoes and the Origin of Their Blood Meal

“…18 Recently, it has been introduced in medical entomology as a tool for the rapid and accurate identification of arthropods, detection of the origin of their blood meal, and detection of associated microorganisms. 23,24,26,[37][38][39][40][41] In entomology, adjustments such as arthropod-based body selection and sample crushing protocol are required for proper MALDI-TOF MS identification of arthropods or detection of associated pathogens. 10,26,38,39 The method of conservation may also be a limiting factor of this method.…”

MALDI-TOF mass spectrometry: a new tool for rapid identification of cercariae (Trematoda, Digenea)

“…This technique is based on laser ionization of sample proteins after co-crystallization with MALDI-matrix and comparison of the obtained mass spectra with a database of reference spectra [5]. MALDI-TOF MS is currently under development for the study of protozoa with potential use for the identification of Leishmania [22], Plasmodium [23] and trypanosomatids [1]. Few applications, however, have been proposed in the field of helminthology.…”