Characterization of Bulinus Snails in Sô-Ava and Azowlissè, Two Localities in Southern Benin, Using PCR-RFLP

Abstract

Schistosomiasis is a public health concern in Benin. Freshwater snails of the genus Bulinus serve as intermediate hosts for schistosomes, trematode parasites responsible for bilharzia. The urinary form, caused by Schistosoma haematobium , is the most widespread and is transmitted to humans by these mollusks, with Bulinus truncatus and Bulinus globosus being the most important species. Effective strategies to combat the transmission of these parasites require a prior understanding of the molecular characterization of Bulinus snails. For this purpose, 293 Bulinus snails were collected and morphologically identified from two localities in southern Benin, Sô-Ava and Azowlissè. The snails were preserved in absolute alcohol. To achieve the set objectives, DNA was extracted from the collected biological material, and SSU gene fragments were amplified. Using PCR-RFLP, the amplified fragments were digested with the restriction endonucleases HaeIII, HinfI, and DdeI to perform molecular characterization. In this study, 80 individuals of B. globosus and 10 of B. truncatus were subjected to molecular analysis. The PCR-RFLP profiles showed bands of different sizes for the Bulinus species when analyzed with the three endonucleases using the SSU molecular marker. PCR-RFLP analysis revealed that the snails belonged to the freshwater genus Bulinus , including Bulinus globosus and B. truncatus , based on reference profiles from studies conducted in Nigeria, which enabled precise identification of these gastropods. This study provided initial insights, although still incomplete, into the molecular diversity of these species.