Lucie Conrad (Homburg / DE), Emmanuel O. Ngbede (Homburg / DE; Makurdi / NG; Braunschweig / DE), Mohammed I. Adah (Makurdi / NG), Saheed T. Yusuf (Abuja / NG), Sören L. Becker (Homburg / DE; Basel / CH), Issa Sy (Homburg / DE)
Abstract text
Introduction
Moniezia spp. and Thysaniezia spp. are intestinal parasites of ruminants that infest the small intestine. Infection with tapeworms occurs worldwide and can lead to symptoms such as diarrhoea, anaemia, and even death in ruminants. The diagnosis of cestodes is mainly based on microscopic observations of eggs and/or molecular detection. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is employed in routine laboratories for the identification of bacteria, fungi, and mycobacteria. Recent studies showed that this method can also be applied for helminths identification.
Objectives
The aim of this study was to assess the capacity of MALDI-TOF MS as a new alternative tool for the identification of adult tapeworms from cattle: Moniezia and Thysaniezia species.
Material and Methods
Sixty-three tapeworms collected from the intestine of slaughtered cattle in Nigeria were morphologically identified as Moniezia spp. and Thysaniezia spp. Molecular confirmation was performed on 9 randomly selected samples to serve as a reference for further MALDI-TOF MS analysis. For this, they were subjected to a protein extraction protocol and measured by MALDI-TOF MS. The obtained spectra were used to create so-called main specific spectra (MSPs) and added to the in-house database. To validate the newly created in-house database, the remaining samples were tested with it after long storage in ethanol. A Log score value (LSV) higher than 1.7 was considered a reliable identification. Furthermore, a clustering analysis (dendrogram) was realized to evaluate the relatedness of the different species.
Results
The 9 adult tapeworms were molecularly confirmed with the detection of the following species: Moniezia benedeni, Moniezia expansa, and Thysaniezia connochaeti. When the in-house database implemented with those species was subsequently tested with the remaining 54 adult tapeworms after long storage in ethanol, 55.1 % of correct identification with an average LSV above 1.7 was achieved. The dendrogram analysis showed a clear separation between the different species (Figure 1).
Conclusion
We conclude that MALDI-TOF MS can be applied for the identification of cestodes. Nevertheless, future research is needed to improve the process.