Analysis of HIV type 1 protease and reverse transcriptase in antiretroviral drug-naive Ugandan adults

We analyzed plasma HIV-1 from 27 antiretroviral drug-naive Ugandan adults. Previous subtype analysis of env and gag sequences from these samples identified subtypes A, C, D, and recombinant HIV-1. Sequences of HIV-1 protease and reverse transcriptase (RT) were obtained with a commercial HIV-1 genotyping system. Subtypes based on protease sequences differed from gag subtypes for 5 of 27 samples, demonstrating a high rate of recombination between the gag and pol regions. Protease and RT sequences were analyzed for the presence of amino acid polymorphisms at positions that are sites of previously characterized drug resistance mutations. At those sites, frequent polymorphisms were detected at positions 36 and 69 in protease and positions 179, 211, and 214 in RT. Subtype-specific amino acid motifs were identified in protease. Most of the subtype A sequences had the amino acids DKKM at positions 35, 57, 69, and 89, whereas most subtype D sequences had the amino acids ERHL at those positions. Detection of those polymorphisms may provide a useful approach for rapid identification of subtype A and D isolates in Uganda. This analysis significantly increases the number of Ugandan protease and RT sequences characterized to date and demonstrates successful use of a commercial HIV-1 genotyping system for analysis of diverse non-B HIV-1 subtypes.