title: Lower prevalence of human immunodeficiency virus type 1 Brazilian subtype B found in northeastern Brazil with slower progression to AIDS.
abstract: Besides being extremely useful in measuring the level of HIV-1 diversity and prevalence in populations, the molecular analysis of genomic sequences provides crucial surveillance support and aids in the development of new therapies and effective vaccines. The present study focused on gag and env DNA and amino acid sequences that were generated from samples taken from 61 infected patients in the City of Salvador, Bahia, located in northeastern Brazil. In order to determine selective pressure and predict coreceptor usage, Bioinformatics tools were employed in phylogeny reconstruction. Fifty-six (91.8%) viruses were classified as belonging to subtype B, three (4.9%) from F1, and two (3.3%) from BF1 recombinants. Based on the characterization of the V3 region, the subtype B strains were represented by eight (18.2%) Brazilian variants (B'-GWGR), 20 (46.5%) European/EUA B variants (GPGR), and 15 (34.9%) GXGX variants. The mean time elapsed since diagnosis was 13 years among subtype B' and 9 years in subtype B. The mean dN/dS ratios from the GWGR, GPGR, and GXGX groups, when compared to an HXB2 reference, were 0.72, 0.77, and 0.67, respectively. Seventy-six percent of the viruses studied were predicted to use the CCR5 coreceptor for cell entry (R5 viruses), while 24% were predicted to use the CXCR4 or were classified as dual tropic viruses. The prevalence of subtypes B' and recombinant B/F1 was shown to be lower than findings from previous studies performed both in Brazil (B') and in Bahia (B/F1). The association between subtype B' and a lengthy period of time since diagnosis can be correlated with a slower disease progression in infected patients, when compared with those infected with subtype B.
authors.affiliation: Advanced Public Health Laboratory, Gonçalo Moniz Research Center , Oswaldo Cruz Foundation, Salvador, BA, Brazil.
authors.forename: Adriano Fernando
authors.initials: AF
authors.lastname: Araujo
authors.forename: Carlos
authors.initials: C
authors.lastname: Brites
authors.forename: Joana
authors.initials: J
authors.lastname: Monteiro-Cunha
authors.forename: Luciane Amorim
authors.initials: LA
authors.lastname: Santos
authors.forename: Bernardo
authors.initials: B
authors.lastname: Galvao-Castro
authors.forename: Luiz Carlos Junior
authors.initials: LC
authors.lastname: Alcantara
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D016000:Cluster Analysis; D018450:Disease Progression; D005260:Female; D005838:Genotype; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D015728:Receptors, HIV / Q000502:physiology; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D053586:Virus Internalization; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D015728:Receptors, HIV; D054299:env Gene Products, Human Immunodeficiency Virus; D054301:gag Gene Products, Human Immunodeficiency Virus