Freshwater snails of the genera Biomphalaria, Bulinus, and Oncomelania are intermediate hosts of schistosomes that cause human schistosomiasis, one of the most significant infectious neglected diseases in the world. Identification of freshwater snails is usually based on morphology and potentially DNA-based methods, but these have many drawbacks that hamper their use. MALDI-TOF MS has revolutionised clinical microbiology and has emerged in the medical entomology field. 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.

中文翻译：

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MALDI-TOF 质谱法用于鉴定来自塞内加尔的淡水蜗牛，包括血吸虫的中间宿主。

Bimphalaria、Bulinus 和 Oncomelania 属的淡水蜗牛是导致人类血吸虫病的血吸虫的中间宿主，而血吸虫病是世界上最重要的被忽视的传染性疾病之一。淡水蜗牛的鉴定通常基于形态学和可能基于 DNA 的方法，但这些方法有许多缺点，阻碍了它们的使用。MALDI-TOF MS 彻底改变了临床微生物学，并在医学昆虫学领域崭露头角。本研究旨在评估 MALDI-TOF MS 分析，以使用来自不同身体部位的蛋白质提取物来鉴定冷冻和乙醇储存的蜗牛物种。共有 530 个野外标本，属于 9 个物种（Biomphalaria pfeifferi、Bulinus forskalii、Bulinus senegalensis、Bulinus truncatus、Bulinus globosus、Bellamya unicolor、Cleopatra bulimoides、Lymnaea natalensis、Melanoides tuberculata）和 89 个实验室饲养标本，包括 3 个物种（Bi本研究使用Bu. pfeifferi、Bu. forskalii、Bu. truncatus）。对于冷冻蜗牛，使用 127 个现场饲养样本和 74 个实验室饲养样本的足部来验证优化的 MALDI-TOF MS 方案。光谱分析产生了种内再现性和种间特异性，从而在盲查询中正确识别了所有标本，对数得分值大于 1.7。第二步，我们证明 MALDI-TOF MS 还可以使用从足部提取的蛋白质，使用包括大量乙醇保存标本的特定数据库来识别乙醇保存的蜗牛。这项研究首次表明，MALDI-TOF MS 是快速鉴定冷冻和乙醇储存的淡水蜗牛的可靠工具，无需任何软体动物学专业知识。