The low stringency-polymerase chain reaction (LS-PCR) with
a pair of specific primers for the amplification of the 18S
rRNA gene was evaluated as a means of differentiating between
the two Schistosoma mansoni intermediate host species
in Brazil: Biomphalaria glabrata and B.
tenagophila. Individual snails obtained from different
states of Brazil were used and the amplification patterns
obtained showed a high degree of genetic variability in these
species. Nevertheless, 4 and 3 clearly defined specific
diagnostic bands was observed in individuals from B.
glabrata and B. tenagophila respectively. The
detection of snail specific diagnostic bands suggests the
possibility of reliable species differentiation at the DNA
level using LS-PCR.