| This work shows the complete nucleotide sequences of six dengue-1 (DEN-1) viruses isolated from Paraguay and Argentina in 2000 from patients with dengue fever. Sequences of strains 259par00, 280par00, 295arg00, 297arg00, and 301arg00 are each 10375 nucleotides long and can encode a polyprotein of 3392 amino acids. Strain 293arg00 circulated as a "wild type + deletion mutant" quasispecies, with a subpopulation characterized by a 3-nucleotide deletion in the NS4A region. This variant, containing a 3 amino acid change in the NS4A protein, was found as a minority population in one additional partially-sequenced isolate from the same outbreak. These six South American strains group into two different clades of the "American-African" DEN-1 genotype---one clade is most closely related to strains isolated from Brazil in 1997, the other to a Peruvian strain isolated in 1991 for which only partial sequence information is available. Completely sequenced DEN-1 viruses isolated worldwide comprise at least four different genotypes according to previously defined classification criteria. |
