Real-time PCR strategy for rapid discrimination among main lymnaeid species from Argentina

Snails of the Family Lymnaeidae act as an intermediate hosts of Fasciola hepatica worldwide. The taxonomy of lymnaeid species is relevant for epidemiological studies and molecular strategies are increasingly used for that purpose. This work presents the first report of a real-time PCR approach used to identify the most important lymnaeid species in the Southern Cone of South America. Species discrimination is based on the sequence polymorphism located within the helix E10-1 of the variable region V2 of the 18S rRNA genes, which yields amplicons with clearly different melting temperatures. This procedure minimises the risk of carry-over contamination because it does not require post-PCR manipulations, and the whole protocol can be completed in less than 4 h with a single snail foot as starting material. This method was successfully carried out in a blind study that included a panel of 20 Galba truncatula, 5 Lymnaea viatrix, 5 Lymnaea diaphana and 5 Pseudosuccinea columella specimens from different endemic areas for fasciolosis. This molecular approach constitutes a key laboratory tool complementing ecological studies that ultimately will promote more efficient control strategies.