GENOMIC CHARACTERIZATION OF BRAZILIAN HEPATITIS-C VIRUS GENOTYPES 1A AND 1B

Parts of 5' non-coding (5' NC) and of E1 envelope regions of the hepat itis C virus (HCV:) genome were amplified from sera of 26 Brazilian an ti-HCV antibody-positive patients using the reverse transcription-poly merase chain reaction (RT-PCR). Fourteen samples were PCR positive wit h primers from the 5' NC region and 8 of them were also positive with primers from the E1 region. A genomic segment of 176 bp from the E1 re gion of 7 isolates was directly sequenced from PCR products. The seque nces were compared with those of HCV strains isolated in other countri es and the Brazilian isolates were classified by phylogenetic analysis into genotypes 1a and 1b. This could have a clinical importance since it has been shown that individuals infected with type 1 viruses are l ess Likely to respond to treatment with interferon than individuals in fected with types 2 and 3 viruses. Two quasispecies isolated from the same patient with an interval of 13 months differed by two base substi tutions (1.1%). The sequence of another isolate presented a three-nucl eotide deletion at codon 329.