Assessment of MALDI-TOF MS biotyping for Borrelia burgdorferi sl detection in Ixodes ricinus

Abstract

Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been demonstrated to be useful for tick identification at the species level. More recently, this tool has been successfully applied for the detection of bacterial pathogens directly in tick vectors. The present work has assessed the detection of Borrelia burgdorferi sensu lato in Ixodes ricinus tick vector by MALDI-TOF MS. To this aim, experimental infection model of I. ricinus ticks by B. afzelii was carried out and specimens collected in the field were also included in the study. Borrelia infectious status of I. ricinus ticks was molecularly controlled using half-idiosome to classify specimens. Among the 39 ticks engorged on infected mice, 14 were confirmed to be infected by B. afzelii. For field collection, 14.8% (n = 12/81) I. ricinus ticks were validated molecularly as infected by B. burgdorferi sl. To determine the body part allowing the detection of MS protein profile changes between non-infected and B. afzelii infected specimens, ticks were dissected in three compartments (i.e. 4 legs, capitulum and half-idiosome) prior to MS analysis. Highly reproducible MS spectra were obtained for I. ricinus ticks according to the compartment tested and their infectious status. However, no MS profile change was found when paired body part comparison between non-infected and B. afzelii infected specimens was made. Statistical analyses did not succeed to discover, per body part, specific MS peaks distinguishing Borrelia-infected from non-infected ticks whatever their origins, laboratory reared or field collected. Despite the unsuccessful of MALDI-TOF MS to classify tick specimens according to their B. afzelii infectious status, this proteomic tool remains a promising method for rapid, economic and accurate identification of tick species. Moreover, the singularity of MS spectra between legs and half-idiosome of I. ricinus could be used to reinforce this proteomic identification by submission of both these compartments to MS.

Improvement of mosquito identification by MALDI-TOF MS biotyping using protein signatures from two body parts

“…These MS pattern properties reinforce the species identification accuracy and reduce the risk of misidentification. The MS spectra specificity according to body part used, was also reported in others arthropods such as ticks [ 35 ] and it has been recommended to submit legs and half-idiosome from the same tick specimen to MS for MS reference DB creation or to strengthen specimen identification [ 35 ].…”

A Novel Rapid Sample Preparation Method for MALDI-TOF MS Permits Borrelia burgdorferi Sensu Lato Species and Isolate Differentiation

“…For borrelia cultures, such procedures are not applicable due to its growth in liquid medium and requirement of very protein rich, complex medium (Preac-Mursic et al, 1986). MALDI-TOF MS has been explored for the detection of vector-borne pathogens and simultaneous identification of vector species (Yssouf et al, 2014;Yssouf et al, 2016;Boyer et al, 2017). Whilst in some cases the technology offered exciting advantages over other methods, it remained unsuccessful in others.…”

Development of MALDI-TOF mass spectrometry for the identification of lice isolated from farm animals

“…or spotted fever group Rickettsia spp. [3,10,11,43,49], and fleas infected or not with Bartonella spp. [10].…”