title: Low prevalence of primary antiretroviral resistance mutations and predominance of HIV-1 clade C at polymerase gene in newly diagnosed individuals from south Brazil.
abstract: We describe preliminary molecular characterization of HIV-1 pol from 108 consecutive HIV seropositive users of a Voluntary Counseling and Testing (VCT) site of Porto Alegre city, the major metropolitan area in the south of Brazil. Protease and partial reverse transcriptase regions were retrotranscribed from plasma HIV-1 RNA and sequenced after direct nested PCR. Principal antiretroviral resistance mutations (ARM) were observed in 3% of the samples, two cases with K103N and one with M41L, L210W and T215Y, all in HIV-1 clade B infected men. At protease region, no principal mutations were observed, but polymorphisms at secondary codons were frequent. Contrary to other areas in the country where clade B dominates, HIV-1 clade C genomes predominated in this study (58%), clade B (32%) and clade F1 (3%). Of the genomes clustering in clade C, almost half (43%) had a small clade B segment at reverse transcriptase, forming a sub-cluster within clade C with a similar recombinant structure and carrying new amino acid signatures. Other mosaic genomes were also observed (7%). The low prevalence of resistance mutations is consistent with previous observations at this geographical location but the high frequency of HIV-1 clade C and CB mosaics seems pre-eminent and warns close monitoring.
authors.affiliation: Retrovirus Laboratory, Virology Service, Adolfo Lutz Institute, São Paulo, SP, Brazil. rohc@usp.br
authors.forename: Rosangela
authors.initials: R
authors.lastname: Rodrigues
authors.forename: Luciene C
authors.initials: LC
authors.lastname: Scherer
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Oliveira
authors.forename: Heitor Moreira
authors.initials: HM
authors.lastname: Franco
authors.forename: Rosa Dea
authors.initials: RD
authors.lastname: Sperhacke
authors.forename: Joao Leandro Paula
authors.initials: JL
authors.lastname: Ferreira
authors.forename: Simone Martins
authors.initials: SM
authors.lastname: Castro
authors.forename: Isete Maria
authors.initials: IM
authors.lastname: Stella
authors.forename: Luis Fernando Macedo
authors.initials: LF
authors.lastname: Brigido
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019380:Anti-HIV Agents / Q000494:pharmacology*; D001938:Brazil; D024882:Drug Resistance, Viral / Q000235:genetics; D005787:Gene Frequency; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral; D054303:HIV Reverse Transcriptase; D016333:HIV Protease