The HIV-1 epidemic in Bolivia is dominated by subtype B and CRF12_BF "family" strains

Monick L Guimarães,Ketty G Velarde-Dunois,David Segurondo,Mariza G Morgado

doi:10.1186/1743-422x-9-19

Monick L Guimarães, Ketty G Velarde-Dunois + Show 2 more

Open Access

https://doi.org/10.1186/1743-422x-9-19

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Abstract

BackgroundMolecular epidemiological studies of HIV-1 in South America have revealed the occurrence of subtypes B, F1 and BF1 recombinants. Even so, little information concerning the HIV-1 molecular epidemiology in Bolivia is available. In this study we performed phylogenetic analyses from samples collected in Bolivia at two different points in time over a 10 year span. We analyzed these samples to estimate the trends in the HIV subtype and recombinant forms over time.Materials and methodsFifty one HIV-1 positive samples were collected in Bolivia over two distinct periods (1996 and 2005). These samples were genetically characterized based on partial pol protease/reverse transcriptase (pr/rt) and env regions. Alignment and neighbor-joining (NJ) phylogenetic analyses were established from partial env (n = 37) and all pol sequences using Mega 4. The remaining 14 env sequences from 1996 were previously characterized based on HMA-env (Heteroduplex mobility assay). The Simplot v.3.5.1 program was used to verify intragenic recombination, and SplitsTree 4.0 was employed to confirm the phylogenetic relationship of the BF1 recombinant samples.ResultsPhylogenetic analysis of both env and pol regions confirmed the predominance of "pure" subtype B (72.5%) samples circulating in Bolivia and revealed a high prevalence of BF1 genotypes (27.5%). Eleven out of 14 BF1 recombinants displayed a mosaic structure identical or similar to that described for the CRF12_BF variant, one sample was classified as CRF17_BF, and two others were F1pol/Benv. No "pure" HIV-1 subtype F1 or B" variant of subtype B was detected in the present study. Of note, samples characterized as CRF12_BF-related were depicted only in 2005.ConclusionHIV-1 genetic diversity in Bolivia is mostly driven by subtype B followed by BF1 recombinant strains from the CRF12_BF "family". No significant temporal changes were detected between the mid-1990s and the mid-2000s for subtype B (76.2% vs 70.0%) or BF1 recombinant (23.8% vs 30.0%) samples from Bolivia.

Highlights

Molecular epidemiological studies of HIV-1 in South America have revealed the occurrence of subtypes B, F1 and BF1 recombinants
HIV-1 genetic diversity in Bolivia is mostly driven by subtype B followed by BF1 recombinant strains from the CRF12_BF “family”
No significant temporal changes were detected between the mid-1990s and the mid2000s for subtype B (76.2% vs 70.0%) or BF1 recombinant (23.8% vs 30.0%) samples from Bolivia

Summary

Introduction

Molecular epidemiological studies of HIV-1 in South America have revealed the occurrence of subtypes B, F1 and BF1 recombinants. In this study we performed phylogenetic analyses from samples collected in Bolivia at two different points in time over a 10 year span We analyzed these samples to estimate the trends in the HIV subtype and recombinant forms over time. The HIV-1 BF1 Brazilian epidemic is driven mainly by a myriad of different URFs_BF and at least five distinct CRFs_BF [14,15,16,17,18,19], unrelated to CRF12_BF, which usually show no common mosaic recombinant profile among one another Another important difference is that some “pure” full-length subtype F1 genomes have been described in Brazil [20], while the frequency of such full-length subtype F1 viruses or even non-recombinant subtype F1 pol sequences is almost absent in other South American countries [8,12,21,22]

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