title: Genetic analysis of culture-negative UNAIDS subtype C samples.
abstract: To help in the vaccine development, WHO-UNAIDS launched a program for the isolation and characterization of subtype C viruses, the most prevalent HIV-1 subtype in the world. Isolates were obtained from Brazil, China, India, Israel, and South Africa, countries in which these strains are circulating. In this study we genetically characterized a set of samples displaying the culture-negative phenotype by sequencing the nucleotides of three genomic regions: the p17 region of the gag gene, the C2V3C3 fragment of the env gene, and the nef gene. The association of the culture-negative phenotype with the nef gene was studied, and we found a significant accumulation of gene alterations. Except for one B/C recombinant from India, the samples studied formed a monophylogenetic subtype C clade, although samples from Brazil formed a statistically significant, independent subcluster in two of the three genes analyzed.
authors.affiliation: Centro National de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Sánchez-Merino
authors.forename: Concepción Casado
authors.initials: CC
authors.lastname: Herrero
authors.forename: Angela
authors.initials: A
authors.lastname: Amorin-Nink
authors.forename: Hagen
authors.initials: H
authors.lastname: von Briesen
authors.forename: Cecilio
authors.initials: C
authors.lastname: López-Galíndez
mesh_terms: D000328:Adult; D001208:Asia; D001938:Brazil; D005260:Female; D015752:Genes, env; D015750:Genes, gag; D015754:Genes, nef; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013019:South Africa; D014776:Virus Cultivation; D014944:World Health Organization