Analysis of HIV-1 Protease Gene Reveals Frequent Multiple Infections Followed by Recombination among Drug Treated Individuals Living in São Paulo and Santos, Brazil

Abstract

The present study investigated the prevalence of HIV-1 multiple infections in a population composed by 47 patients under HAART failure and enrolled at the National DST/AIDS, Program, Ministry of Health, Brazil.Detection of multiple infections was done using a previously published RFLP assay for the HIV-1 protease gene, which is able of distinguishing between infections caused by a single or multiple HIV-1 subtypes. Samples with multiple infections were cloned, and sequence data submitted to phylogenetic analysis. We were able to identify 17 HIV-1 multiple infections out of 47 samples. Multiple infections were mostly composed by a mixture of recombinant viruses (94%), with only one case in which protease gene pure subtypes B and F were recovered. This is the first study that reports the prevalence of multiple infections and intersubtype recombinants in a population undergoing HAART in Brazil. Based on the data there was a steep increase of multiple infections after the introduction of the combined antiretroviral therapy in Brazil. Cases of multiple infections may be associated with HIV-1 genetic diversity through recombination allowing for the generation of viruses showing a combination of resistance mutations.

Extensive variation in drug-resistance mutational profile of Brazilian patients failing antiretroviral therapy in five large Brazilian cities

“…In Brazil, circulation of different viral subtypes has been reported, with variable prevalence according to different regions. 3 , 4 , 5 , 6 There is scarce information on regional differences regarding mutational profile, availability of remaining active drugs, and the variability of susceptibility rates for different ARV drugs, according to the use of different algorithms.…”