Hepatitis B virus genotypes and precore and core mutants in Brazilian patients.
A method for genotyping hepatitis B virus by partial HBsAg gene sequencing with primers common to all known genotypes was developed. Mutations related to anti-HBs resistance are also detected with this method. Samples from 103 Brazilian patients were analyzed. Precore and core region of these viruses were also sequenced in 101 patients. Genotypes A, B, C, D, and F were found with frequencies of 49.5, 2.9, 13.6, 24.3, and 9.7%, respectively. Genotypes B and C were found only in Asian patients, whereas genotypes A, D, and F were more common in patients without an Asian background. Precore mutants were found in 32 (31.7%) of 101 patients, with a higher frequency in those infected with genotype D (22 of 25 [88.0%]). Analysis of nucleotide 1858 showed presence of thymine in all patients with genotypes B, C, and D and in a few patients with genotypes A (10.0%) and F (30.0%), who showed more frequently the presence of cytosine. This nucleotide was closely related to the presence of precore mutants. Mutations in the basal core promoter were found in 64 of 101 (63.4%) samples. These mutations were more frequent in patients infected with genotype F (90.0%) and less frequent in patients infected with genotype B (33.3%). Deletions in this region were found in two genotype C-infected patients.
Sitnik
Roberta
R
Serviço de Virologia, Instituto Adolfo Lutz, Av. Brigadeiro Luiz Antonio, 4701, 01401-002 São Paulo, SP, Brazil.
Pinho
João Renato Rebello
JR
Bertolini
Dennis Armando
DA
Bernardini
Antonio Plinio
AP
Da Silva
Luiz Caetano
LC
Carrilho
Flair José
FJ
D000595:Amino Acid Sequence; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA
D006514:Hepatitis B Surface Antigens