Evaluating Different Storage Media for Identification of Taenia saginata Proglottids Using MALDI-TOF Mass Spectrometry

Abstract

Taenia saginata is a helminth that can cause taeniasis in humans and cysticercosis in cattle. A species-specific diagnosis and differentiation from related species (e.g., Taenia solium) is crucial for individual patient management and disease control programs. Diagnostic stool microscopy is limited by low sensitivity and does not allow discrimination between T. saginata and T. solium. Molecular diagnostic approaches are not routinely available outside research laboratories. Recently, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) was proposed as a potentially suitable technique for species-specific helminth diagnosis. However, standardized protocols and commercial databases for parasite identification are currently unavailable, and pre-analytical factors have not yet been assessed. The purpose of this study was to employ MALDI-TOF MS for the identification of T. saginata proglottids obtained from a human patient, and to assess the effects of different sample storage media on the technique’s diagnostic accuracy. We generated T. saginata-specific main spectral profiles and added them to an in-house database for MALDI-TOF MS-based diagnosis of different helminths. Based on protein spectra, T. saginata proglottids could be successfully differentiated from other helminths, as well as bacteria and fungi. Additionally, we analyzed T. saginata proglottids stored in (i) LC–MS grade water; (ii) 0.45% sodium chloride; (iii) 70% ethanol; and (iv) 37% formalin after 2, 4, 6, 8, 12, and 24 weeks of storage. MALDI-TOF MS correctly identified 97.2–99.7% of samples stored in water, sodium chloride, and ethanol, with log-score values ≥2.5, thus indicating reliable species identification. In contrast, no protein spectra were obtained for samples stored in formalin. We conclude that MALDI-TOF-MS can be successfully employed for the identification of T. saginata, and that water, sodium chloride, and ethanol are equally effective storage solutions for prolonged periods of at least 24 weeks.

Combination of MALDI-TOF Mass Spectrometry and Machine Learning for Rapid Antimicrobial Resistance Screening: The Case of Campylobacter spp.

“…It is a fast and cost-efficient process, with a positive impact on public health analytical pipelines (Ge et al, 2017;Rodríguez-Sánchez et al, 2019). Identification of other organisms, like protozoa (Del Chierico et al, 2016), helminths (Bredtmann et al, 2017;Feucherolles et al, 2019b;Sy et al, 2021;Wendel et al, 2021), viruses (Iles et al, 2020;Rybicka et al, 2021), and arthropods (Tahir et al, 2017;Boucheikhchoukh et al, 2018;Tandina et al, 2018), is also feasible in a research context. However, only the routine identification part of the diagnostics workflow is currently carried out by MALDI-TOF MS.…”

MALDI Mass Spectrometry Imaging: A Potential Game-Changer in a Modern Microbiology

“…Commercial MALDI-TOF MS systems include databases for a large panel of microorganisms—including bacteria [ 7 ], mycobacteria [ 8 ] and fungi [ 9 ]—of medical and food interest. Furthermore, many reports underlined the successful application of MALDI-TOF MS for identification of additional microorganisms—such as viruses [ 10 , 11 , 12 ], ectoparasites[ 13 , 14 ], protozoa and helminths [ 15 , 16 , 17 ]—as well as antimicrobial resistance profiles and subtyping in a research context [ 18 , 19 ]. In the post-genomics world, microbial proteomics will be the foremost complement to other omics-powered technologies as protein activity is the most important factor for understanding biological pathways.…”

Species Delimitation of Hexacorallia and Octocorallia Around Iceland Using Nuclear and Mitochondrial DNA and Proteome Fingerprinting

“…The adverse effect of storage under suboptimal conditions has been investigated several times, and authors report significant changes in detected mass peaks, intensities and identification scores (Mathis et al, 2015;Nebbak et al, 2017;Rossel and Martínez Arbizu, 2018b;Vega-Rúa et al, 2018;Wendel et al, 2021). Even though specimens were stored correctly to the best of our knowledge, signal degeneration was observed in Gersemia sp.…”