HIV-1 pol phylogenetic diversity and antiretroviral resistance mutations in treatment naïve patients from Central West Brazil

Abstract

Background Primary resistance represents a challenge for the control of HIV-1 because it can reduce the efficacy of first line antiretroviral therapy and may impact clinical outcomes. Objectives To describe the prevalence of primary HIV-1 drug resistance and subtypes circulating in Central West Brazil. Study design 103 antiretroviral naïve patients were recruited in Goiânia city, Central West Brazil during 2007–2008. Protease and partial reverse transcriptase regions were retrotranscribed from plasma HIV-1 RNA and 97 were sequenced after direct nested PCR. HIV-1 subtype was assigned by phylogenetic analysis. Primary drug resistance was analyzed by the Calibrated Population Resistance (CPR) tool using Stanford Surveillance Drug Resistance Mutation (SDRM) and International AIDS Society- USA (IAS-USA) major mutation list. Results Primary drug resistance mutations ranged from 8% (IAS) to 10% (SDRM). High level resistance to at least one antiretroviral drug was observed. T215D/S revertant mutations were identified in 4/97 patients. HIV-1 subtype B represented 82.5%, subtype F1 6.2%, subtype C 3.1%, B/F1 7.2% and one sample was a F1/C/B mosaic. HIV-1 subtype C sequences formed a monophyletic cluster with other Brazilian subtype C sequences. Conclusions Our HIV-1 pol sequences from Central West region include the first inland HIV-1 subtype C sequences and help compose the molecular epidemiology map of HIV-1 in Brazil. This data also show that a significant proportion of the naïve patients presented important drug resistance mutations. Therefore naive patients from this setting may benefit from pre-treatment genotypic testing to optimize the choice of antiretroviral drugs and to help control HIV-1 transmission.