MALDI-TOF mass spectrometry for the identification of freshwater snails from Senegal, including intermediate hosts of schistosomes

This study aims to evaluate MALDI-TOF MS profiling for the identification of both frozen and ethanol-stored snail species using protein extracts from different body parts. A total of 530 field specimens belonging to nine species (Biomphalaria pfeifferi,Bulinus forskalii,Bulinus senegalensis,Bulinus truncatus,Bulinus globosus,Bellamya unicolor,Cleopatra bulimoides,Lymnaea natalensis,Melanoides tuberculata) and 89 laboratory-reared specimens, including three species (Bi.pfeifferi,Bu.forskalii,Bu.truncatus) were used for this study. For frozen snails, the feet of 127 field and 74 laboratory-reared specimens were used to validate the optimised MALDI-TOF MS protocol. The spectral analysis yielded intra-species reproducibility and inter-species specificity which resulted in the correct identification of all the specimens in blind queries, with log-score values greater than 1.7. In a second step, we demonstrated that MALDI-TOF MS could also be used to identify ethanol-stored snails using proteins extracted from the foot using a specific database including a large number of ethanol preserved specimens. This study shows for the first time that MALDI-TOF MS is a reliable tool for the rapid identification of frozen and ethanol-stored freshwater snails without any malacological expertise.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research