Occurrence of Biomphalaria cousini (Mollusca: Gastropoda) in Brazil and its susceptibility to Schistosoma mansoni (Platyhelminths: Trematoda)

Abstract

In Brazil, there are three intermediate snail vectors and two potential hosts of Schistosoma mansoni. Previous studies showed three variant molecular profiles to B. amazonica and evidenced intraspecific variations using sequence data. In this context, the aim of this study was to verify whether such differences would correspond to either B. amazonica or B. cousini. The snails were morphologically identified; PCR-RFLP and sequencing were carried out. Besides, B. cousini were submitted to susceptibility experiments to S. mansoni. Noteworthy, morphological data of Brazilian specimens predominantly showed the morphology described for B. amazonica. Nevertheless, PCR-RFLP results exhibited three variant molecular profiles for the specimens previously identified as B. amazonica and the phylogenetic analyses showed two groups one to B. amazonica and another to B. cousini. Furthermore, B. cousini showed to be susceptible to S. mansoni. These results confirm the occurrence of B. cousini in Brazil and points to the risk of introduction of schistosomiasis mansoni into new areas.

Predicting the spatial distribution of Biomphalaria straminea, a potential intermediate host for Schistosoma mansoni, in China

“…Several biotic and abiotic factors in the environment control Biomphalaria abundance and distribution (Brown, 1994;Rollinson, 2011). Nevertheless, some species of Biomphalaria have proven successful in occupying new ecological niches that in turn led to schistosomiasis expansion, even to non-endemic areas (Sturrock, 1973;Yousif et al, 1996;Lardans and Dissous, 1998;Pointier et al, 2005a;Teodoro et al, 2010).…”

Pattern of Genetic Divergence of Mitochondrial DNA Sequences in Biomphalaria tenagophila Complex Species Based on Barcode and Morphological Analysis

“…Nearly one -third of these species occur in freshwater ecosystems related to the main drainage river basins in Brazil (Estrada et al,2006;Teodoro,2010),where Biomphalaria glabrata (Say,1818),Biomphalaria tenagophila (Orbigny,1835) and Biomphalaria straminea (Dunker,1848) have serious impact on human health for these species host Schistosoma mansoni Sambon 1907 (Figure 1). Palasio, R.G.S., 2011) showing the worldwide distribution of the 37 Biomphalaria species, the 26 neotropical Biomphalaria species and the 11 species and 1 subspecies naturally described in Brazil (•) (Brasil,Ministério da Saúde 2007;Carvalho et al, 2008;Teodoro et al,2010). An asterisk indicates Schistosoma mansoni host species (Palasio, RGS, 2011).…”

Hybridism between Biomphalaria cousini and Biomphalaria amazonica and its susceptibility to Schistosoma mansoni

“…Fernandez and Thiengo (2006) confirmed this result using B. amazonica from the state of Mato Grosso, with a low index of infection (3.79%, 13.63% and 9.09%). Teodoro et al (2010) showed a higher infection index of B. cousini to the LE strain of S. mansoni (31.6%). Our results showed that hybrids can be considered a potential host of the trematode because they proved to be susceptible to the three strains of S. mansoni used, LE, SJ and AL (4.4%, 5.6% and 2.2%, respectively).…”