Molecular Characterization and Phylogeny of Bulinus species in North Central, Nigeria

Abstract

Background: Bulinus species are intermediate host of urogenital schistosomiasis, which is widespread in Nigeria. Morphological identification of these snails is problematic; hence, the molecular method is recommended. Therefore, this study aims to characterize Bulinus species sampled from schistosome-endemic areas of North Central Nigeria. Methods: Bulinus species were collected from two Local Government Areas in North Central Nigeria. Infection in snails were detected by targeting Dra1 repeat using polymerase chain reaction (PCR). Snails were character-ized by amplifying the internal transcribed spacer region of the 5.8s ribosomal RNA gene and restriction frag-ment length polymorphism. Some representative samples were sequenced, and the phylogenetic relationship was compared with other African sequences from the European Molecular Biology Laboratory (EMBL) data-base. Results: Out of 368 snails sampled, 37.5 % were positive for schistosome infection. Our study recorded a few B. globosus compared with B. truncatus. Similarly, more snails were recovered from Patigi Local Government (LGA) than Edu LGA. However, schistosome infections in Edu LGA (39.3%) were higher than in Patigi LGA (37.8%). The phylogenetic relationship shows that the dominant species (Bulinus truncatus) matched other se-quences deposited in the EMBL database. However, some mutations were noticeable within the sequence of B. truncatus in our study, but the expressed proteins were not affected. Conclusion: The infection status in snail species is high, contributing to schistosomiasis transmission in the study area. PCR-RFLP showed more accuracy in snail identification than morphological methods.