title: Distribution of human immunodeficiency virus type 1 subtypes in the State of Amazonas, Brazil, and subtype C identification.
abstract: Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible "homogenous" subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country.
authors.affiliation: Departamento de Parasitologia, Universidade Federal do Amazonas, Manaus, AM, Brasil.
authors.forename: L K H
authors.initials: LK
authors.lastname: Cunha
authors.forename: S
authors.initials: S
authors.lastname: Kashima
authors.forename: M F C
authors.initials: MF
authors.lastname: Amarante
authors.forename: R
authors.initials: R
authors.lastname: Haddad
authors.forename: E S
authors.initials: ES
authors.lastname: Rodrigues
authors.forename: K L T
authors.initials: KL
authors.lastname: Silva
authors.forename: T A
authors.initials: TA
authors.lastname: Lima
authors.forename: D B
authors.initials: DB
authors.lastname: Castro
authors.forename: F C
authors.initials: FC
authors.lastname: Brito
authors.forename: E G
authors.initials: EG
authors.lastname: Almeida
authors.forename: D T
authors.initials: DT
authors.lastname: Covas
authors.forename: A
authors.initials: A
authors.lastname: Malheiro
mesh_terms: D000328:Adult; D001483:Base Sequence; D001782:Blood Donors; D015153:Blotting, Western; D001938:Brazil / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015752:Genes, env / Q000235:genetics; D015750:Genes, gag / Q000235:genetics; D015751:Genes, pol / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D055815:Young Adult