MALDI-TOF MS protein profiling for the rapid identification of Chagas disease triatomine vectors and application to the triatomine fauna of French Guiana

Abstract

Triatomines are haematophagous insects involved in the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease. The vector competence of these arthropods can be highly variable, depending on the species. A precise identification is therefore crucial for the epidemiological surveillance of T. cruzi and the determination of at-risk human populations. To circumvent the difficulties of morphological identification and the lack of comprehensiveness of the GenBank database, we hereby propose an alternative method for triatomine identification. The femurs of the median legs of triatomines from eight different species from French Guiana were subjected to matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis. Method evaluation was performed on fresh specimens and was applied to dry specimens collected between 1991 and 2003. Femur-derived protein extracts provided reproducible spectra within the same species along with significant interspecies heterogeneity. Validation of the study by blind test analysis provided 100% correct identification of the specimens in terms of the species, sex and developmental stage. MALDI-TOF mass spectrometry appears to be a powerful tool for triatomine identification, which is a major step forward in the fight against Chagas disease.

Detection of Bartonella spp. in fleas by MALDI-TOF MS

“…Recently, MALDI-TOF MS technology has been successfully used for the identification of arthropods such as fleas [ 10 ], mosquitoes [ 20 , 23 ], Culicoides [ 21 ], ticks [ 19 , 24 ], sand flies [ 25 ] tsetse flies [ 26 ] and triatomines [ 22 ]. The success of this method requires the standardization of sample preparation protocols to allow sharing and comparison of MS reference spectra and results between research laboratories.…”

“…pictipes , R . robustus , Panstrongylus geniculatus , Eratyrus mucronatus ) and bedbugs ( Cimex lectularius )[ 8 , 10 , 12 , 19 – 22 ].…”

“…An LSV was obtained for each spectrum of the samples tested blindly. For each specimen, the spectrum with the highest LSVs was selected for identification [ 22 ].…”

Blood meal identification in the cryptic species Anopheles gambiae and Anopheles coluzzii using MALDI-TOF MS

“…The CCIs are calculated by dividing spectra into intervals and comparing these intervals across a dataset. The composition of correlations of all intervals provides the CCI, which is used as a parameter that defines the distance between spectra [ 9 ].…”

“…The results of the database queries are presented as Log Score Values (LSVs) for each spectrum given corresponding to a matched degree of signal intensities of mass spectra of the query and the reference spectra. LSVs ranged from 0 to 3 [ 9 ]. LSVs greater than 1.8 were considered as the threshold value for relevant identification, as previously published [ 17 ].…”