title: The molecular epidemiology and drug resistance determination of HIV type 1 subtype B infection in Barbados.
abstract: To better understand the emergence of HIV-1 variants in Barbados and the association with transmission modes, we analyzed phylogenetic relationships and genetic variability among HIV-1 strains collected in 1996 from 36 antiretroviral therapy-naive patients. Only subtype B variants were present in this sampling, based on analysis of HIV-1 envelope (env) C2V3, protease (PR), and reverse transcriptase (RT) sequences. The genetic diversity of env sequences was broad (13.9%; range, 5.9-24.9%), suggesting multiple introductions of distinct HIV-1 strains to the island. The frequency of subtype B HIV-1 variants with similar env V3 features, including the tetrameric tips, GPGR and GPGK, the threonine deletion at position 23, and the substitution of threonine to arginine at position 22, was comparable in heterosexual, bisexual, and homosexual patients. Analyses of amino acid variations in PR sequences revealed a lack of major drug resistance-conferring mutations and a high (90%) prevalence of secondary mutations at positions 36, 63, 71, and 77. While the occurrence of 361, 63P, and 71T mutations in Barbadian strains was similar to the global prevalence for subtype B variants, the frequency (64%) of the V77I mutation was more than three times that seen worldwide. Only two RT antiretroviral resistance mutations (M41L and T215Y) were observed, both from a single patient. This comprehensive genetic analysis documents a broad diversity within HIV-1 subtype B in Barbados and suggests a lack of association between particular subtype B variants and transmission modes.
authors.affiliation: School of Clinical Medicine and Research, University of the West Indies, Barbados. mvgittens@partners.org
authors.forename: Marquita V
authors.initials: MV
authors.lastname: Gittens
authors.forename: William W
authors.initials: WW
authors.lastname: Roth
authors.forename: Timothy
authors.initials: T
authors.lastname: Roach
authors.forename: H Gene
authors.initials: HG
authors.lastname: Stringer
authors.forename: Danuta
authors.initials: D
authors.lastname: Pieniazek
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Bond
authors.forename: Paul N
authors.initials: PN
authors.lastname: Levett
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001460:Barbados / Q000453:epidemiology; D024882:Drug Resistance, Viral; D005260:Female; D014644:Genetic Variation; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D054303:HIV Reverse Transcriptase; D016333:HIV Protease