Signature pattern analysis of type 1 HCV strains isolated in South America. In (A) the consensus nucleotide sequence in the background set of type 1 HCV strains isolated in South America is shown in black. The consensus nucleotide sequence in the query (signature sequence) set is shown in red. Query sequence signature identified by VESPA is shown in green. Numbers in the figure shows IRES nucleotide positions, relative to strain HCV1b . In (B) an alignment of 5'NCR sequences from strains belonging to the third cluster observed in type 1 HCV strains isolated in the South American region with corresponding consensus sequences of type 1 HCV strains isolated in South America (Background1), Europe (Background 2) or North America (Background3) is shown. Strains are shown by accession number for strains previously described, or by name at the left side of the figure. Identity to consensus sequences is indicated by a dash. Gaps introduced during alignment are indicated by a dot.