Intersubtype BF Recombinants of HIV-1 in a Population of Injecting Drug Users in Argentina

Abstract

The presence of recombinant intersubtypes of HIV-1 in Argentina has been reported since the mid-1990s. In this study, sequences of a region of the gag, pol, and vpu genes of HIV-1 were analyzed in samples of 21 injection drug users (IDUs) residing in the suburbs of the city of Buenos Aires. Genomic characterization and identification of recombination sites were made comparing the 3 regions with reference isolation sequences of subtypes B, F, C, A, and B/F recombinants: CRF12_BF and non-CRF12_BF sequences. Subtype assignment of the analyzed segments was phylogenetically confirmed. All the samples turned out to be BF recombinants in at least 1 of the 3 studied genes. Twelve samples (57%) had the same pattern as the Argentinean CRF12_BF, whereas in the rest, the pattern differed in at least 1 of the 3 genes. The relation of these fragments to the CRF12_BF was phylogenetically verified. These results indicate the predominance of BF recombinants and the presence of a high percentage of sequences closely related to the CRF12_BF in the IDU population in Argentina and suggest a possible association between viral variants and the transmission route.

Molecular screening shows extensive HIV-1 genetic diversity in Central West Brazil

“…This area is a known drug traffic route from South American countries into Brazil, and intravenous drug use is an important exposure category in this area. Recent studies from South America have shown a link between B/F recombinants and extensive intravenous drug use (Hierholzer et al, 2002;Espinosa et al, 2004). Nevertheless, in Central West Brazil B/F isolates were observed in all risk categories.…”

Prevalência de subtipos do HIV-1 em amostra de pacientes de um centro urbano no sul do Brasil

“…18 Estudos realizados na Argentina e Brasil mostraram que usuários de drogas injetáveis e mulheres apresentaram maior freqüência de recombinantes BF. 8,24 No RS, uma forma recombinante específi ca (CRF31_BC) tem apresentado prevalência bastante elevada, diferindo do restante do Brasil, e tem se disseminado no estado vizinho de Santa Catarina e em outros países limítrofes da América do Sul, tais como Uruguai, Paraguai e Argentina. 3,5 No Brasil estima-se que cerca de 506 mil pessoas estejam infectadas, das quais aproximadamente 46 mil estão no RS.…”

Worldwide molecular epidemiology of HIV

“…13 Another subtype B with V3 loop motif GPGRTW was recently described in Venezuela. 21 Brazilian subtype C (or C Br ) has as a characteristic tetramer GPGQ, 13 also found in Portugal, 36 Japan, 99 and India. 80 In relation to the subtype F, Brazilian F Br possesses GPGR motif 13 that has a small difference compared to the Romanian subtype F R with predominant GPGQ motif, occasionally also observed in Brazil.…”

“…18,54 In Argentina, Uruguay, and Brazil the CRF12_BF became prevalent in heterosexual population, and in vertically infected children. 17,36,51,114,116,120,121 In Brazil, the distribution of HIV-1 subtypes assumes diversified patterns according to the geographic regions. In the Brazilian Southern and Southeastern States the rate of subtype B arise to 50%, and subtypes C and F represent 28% and 7%, respectively, 127 while in Northeastern region occurs a high prevalence of B (>80%) followed by a low frequency (<3%) of subtype F and BC recombinant.…”

“…In the evolutionary origin of HIV and SIV it is estimated that the HIV-1/HIV-2 divergence node occurred in the early 1,800s and, the oldest node linking all human and simian viruses date back 600 to 1,200 years, while the HIV-1 strain causing AIDS were estimated to be 50 to 100 years old. 36,44,45,[77][78][79]97 Studying HIV genetic variation at the global level is needed, not only to learn the origins and understand the epidemiology of HIV-1, but also the emergence of subtypes, Circulating Recombinant Forms (CRFs), and intra-subtypes that may be more readily transmitted or have altered virulence, and to ensure that vaccine antigens are directed against strains of the virus that are currently circulating within specific populations.…”