Volume 44, Issue 1
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



A cloned fragment of the ribosomal gene of , pSM 389, which contains part of the small rRNA gene plus a portion of the nontranscribed intergenic spacer, was used in Southern hybridization analyses to investigate genomic variation in natural populations of in Brazil. Genomic DNAs were isolated from schistosomes from infected patients (some of whom did not respond to antischistosomal chemotherapy), and from snails from disparate geographic locations in Brazil. Restriction fragment length polymorphisms (RFLPs) were evident in Southern blot hybridizations of these schistosome DNAs, and the RFLPs indicated that the genomic profiles of a number of Brazilian strains were more similar to each other than they were to parasites from two laboratory reference strains of Puerto Rican origin. In addition, the Brazilian isolates could generally be separated from each other based on these RFLPs. Isolates from the southeastern state of Minas Gerais were more similar to each other than they were to parasites isolated in the northeastern states of Alagoas and Pernambuco. Variation was evident among individual worms from some of the isolates, and these individual variations contributed to the complex RFLP patterns that were characteristic for particular isolates. The variation within a natural population isolated directly from snails at Ressaca, Belo Horizonte, may be more marked than that exhibited by more established strains maintained in the laboratory for numerous generations.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error