title: HTLV-1 infection in blood donors from the Western Brazilian Amazon region: seroprevalence and molecular study of viral isolates.
abstract: To determine the seroprevalence of HTLV-1 in Brazil, and to review the virus molecular epidemiology in this Amazon population (Rio Branco-Acre), 219 blood donors were screened for HTLV-1. Only one case of infection (0.46% seroprevalence) was detected during July 2004 screening at the Acre Hospital Foundation (FUNDACRE). Neighbor-joining and Maximum Likelihood phylogenetic analyses of two (n = 2) complete LTR region sequences were performed with the PAUP* software. Since the HTLV-1 envelope surface (gp46) and transmembrane (gp21) glycoproteins are important for virus fitness, three envelope glycoproteins sequences (n = 3) were analyzed using the Prosite tool to determinate potential protein sites. Phylogenetic analysis demonstrated that the new isolate described in this study, and the unpublished LTR strain described in a previous report belong to the Transcontinental subgroup of the Cosmopolitan subtype, inside the Latin American cluster. A similar result was obtained when submitting, to the Automated Genotyping System, three LTR partial sequences from a previous study of the seroprevalence of HTLV-1 in the same Amazon population. In all analyzed env sequences, the potential protein site was found: two PKC phosphorylation sites at amino acid (aa) positions 310-312 and 342-344, one CK2 phosphorylation site at 194-197aa, three N-glycosylation sites at 222-225aa, 244-247aa and 272-275aa, and a single N-myristylation site at 327-338aa. In conclusion, potential protein sites described in HTLV-1 gp46 and gp21 confirm the presence of conserved sites in the HTLV-1 envelope proteins, likewise phylogenetic analysis suggests a possible recent introduction of the virus into North Brazil.
authors.affiliation: Laboratório Avançado de Saúde Pública, Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil.
authors.forename: Aline Cristina
authors.initials: AC
authors.lastname: Mota-Miranda
authors.forename: Sérgio Pereira
authors.initials: SP
authors.lastname: Araújo
authors.forename: Juarez Pereira
authors.initials: JP
authors.lastname: Dias
authors.forename: Denise Duizit
authors.initials: DD
authors.lastname: Colin
authors.forename: Simone
authors.initials: S
authors.lastname: Kashima
authors.forename: Dimas Tadeu
authors.initials: DT
authors.lastname: Covas
authors.forename: José
authors.initials: J
authors.lastname: Tavares-Neto
authors.forename: Bernardo
authors.initials: B
authors.lastname: Galvão-Castro
authors.forename: Luiz Carlos Junior
authors.initials: LC
authors.lastname: Alcantara
mesh_terms: D001782:Blood Donors; D001938:Brazil / Q000453:epidemiology; D016000:Cluster Analysis; D017124:Conserved Sequence; D015686:Gene Products, env / Q000235:genetics; D005838:Genotype; D015490:HTLV-I Infections / Q000453:epidemiology*; D015368:Human T-lymphotropic virus 1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D016036:Seroepidemiologic Studies
chemical_list: D015686:Gene Products, env; D012367:RNA, Viral