HTLV-1 infection in blood donors from the Western Brazilian Amazon region: seroprevalence and molecular study of viral isolates.
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 Phylogenetic analysis demonstrated that the new isolate described in this study, and the unpublished LTR strain described in a previous report belong to the Transcontinental subgroup of the Cosmopolitan subtype, inside the Latin American cluster.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.
Mota-Miranda
Aline Cristina
AC
Laboratório Avançado de Saúde Pública, Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil.
Araújo
Sérgio Pereira
SP
Dias
Juarez Pereira
JP
Colin
Denise Duizit
DD
Kashima
Simone
S
Covas
Dimas Tadeu
DT
Tavares-Neto
José
J
Galvão-Castro
Bernardo
B
Alcantara
Luiz Carlos Junior
LC
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
D015686:Gene Products, env; D012367:RNA, Viral