Rapid identification of Biomphalaria spp. and diagnosis of Schistosoma mansoni infestation using MALDI-TOF mass spectrometry

This study explores the use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify and differentiate Biomphalaria snails infected with the parasite S. mansoni, which causes schistosomiasis. The study was conducted on two snail species, Biomphalaria pfeifferi (collected in the field in Senegal) and Biomphalaria glabrata (a laboratory strain). The snails were infected in the laboratory with S. mansoni miracidia, and their infection was confirmed by cercariae emission tests and quantitative PCR (qPCR). MALDI-TOF MS was then used to analyse proteins from infected and uninfected snails to identify spectral differences. Based on protein profiles, the results of MALDI-TOF mass spectrometry made it possible to accurately differentiate between S. mansoni-infected snails and uninfected snails. An increase in the number of peaks detected and their intensity was observed for the spectra of S. mansoni-infected snails compared to uninfected snails. The application of principal component analysis (PCA) to these mass spectrometry profiles confirmed the discrimination between the two groups according to their infection status. In addition, specific discriminating peaks were identified for each snail species, allowing for the distinction of infected from uninfected snails. The present study revealed, for the first time, that MALDI-TOF MS appears to be a rapid, reliable, and specific tool for the diagnosis of schistosomiasis in snails, offering promising prospects for the surveillance and control of this disease in endemic areas. However, further work is needed to establish a MALDI-TOF MS reference spectra database specific to Schistosoma parasites and to standardise sample collection, storage, and preparation in order to apply this technique in the field.Author summary: This study investigates the use of Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify Biomphalaria snails infected with the Schistosoma mansoni parasite, which causes schistosomiasis. Researchers focused on two snail species: Biomphalaria pfeifferi from Senegal and a laboratory strain of Biomphalaria glabrata. Infected snails were confirmed through tests that measured the emission of cercariae and quantitative PCR (qPCR). The MALDI-TOF MS analysis revealed distinct protein profiles between infected and uninfected snails. In particular, infected snails showed a higher number of spectral peaks and greater peak intensity. By applying principal component analysis (PCA) to the mass spectrometry data, the study successfully differentiated between the two groups based on their infection status. Notably, specific peaks were identified that distinguished each snail species. This research demonstrates that MALDI-TOF MS can serve as a quick and reliable method for diagnosing schistosomiasis in snails, which could enhance disease surveillance and control in affected regions. However, further work is necessary to develop a comprehensive reference database and standardise protocols for field application.